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PRESENTED BY 


“LIBRARY OF CONGRESS. | 


UNITED STATES OF AMERICA, 


U.S. DEPARTMENT OF AGRICULTURE. 


BUREAU OF ANIMAL INDUSTRY. 


De EES 


ANIMAL PARASITES OF SHEEP. 


BY 


COOPER CURTICE, D. V.&., M. D. 


(ub 


PUBLISHED BY AUTHORITY OF THE SECRETARY OF AGRICULTURE. 


WASHINGTON: 
GOVERNMENT PRINTING OFFICE, 
1890. 

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TABLE OF CONTENTS. 


Page. 
Matherot trans niiuta leas acres cli eneepaie = ofete scm misiainal~ teste) eininielelsi si=swl-(=)= === ol == a 
GenicEniercin ne eae feo ae a= ae aia na robes c cis ane aoa er teece se cate cele wince otis 9 
Parasites of the nose: 
Grubunsthehead: Gistrisonvs, Wintias2. 2s. --o 256 eae cen een as ose ~e- 26 
Parasites of the skin: Phthiriasis, Acariasis. 
The sheep tick, Melophagus ovinus, Linn ......----.------------------- 39 
The sheep louse, Trichodectes sphwrocephalus, Nitzsch..---..-.---------- 45 
The goat louse, Trichodectes limbatus, Gervais, and Trichodectes climax, 
INTIS A een sons DooOceloeus HosBeas Send Ghubod HoScCUbSCacdieceu pone 49 
Scab insects: Acariasis, itch, scab. 
Head scab, Sarcoptes scabiei, de Geer, var. 0vi8..---------------------- 53 
Common scab, Psoroptes communis, Fiirst, var. ovis..---.-------------- 56 
Foot scab, Chorioptes communis, Verheyen, var. 0vis....---.----------- 65 
Parasites of diverse organs : 
The pentastoma, Linguatula tanioides, Rud... -.--.---------------+---- 69 
Immature tape-worms: 
Bladder worms, Tenia marginata, Batsch .-...----.-----.------++----- 72 
Gid or staggers, Tenia conurus, Kiich......--.--.-------------+------ 83 
Hydatids, Tania echinococcus, V.Sieb..---...---. ------ -------------- 86 
The mutton measle, Twnia tenella, Cobbold.......-.-..---.---------- 87 
Parasites of the alimentary canal and appendages: 
Adult tape-worms: 
The fringed tape-worm, Tenia fimbriata, Diesing..---..-.----.--------- 89 
The broad tape-worm, Tenia expansa, Rud ...-.. 2.22. .------seeeee-- 113 
Liver-flukes : 
The large liver-fluke, Distoma hepaticum, Linn........---..----.------ 127 
The small liver-fluke, Distoma lanceolatum, Mehlis......---..--------- 137 
The stomach worms: 
Amphistoma conicum, Zeder .....---- See prise cisieiasice sh osccisiomeee sane 138 
SELONGULUS CONLONTLS hu Cannes anata clea acne os tose asa se Se earescs 141 
Intestinal round worms: ; 
Imntroductonysremackesersse aes nae apeee se ecee seine sae wice =n 145 
SURE UCE TG OUADS 10 | oe dels Gece cone Beeuoe Coe CUD SOE SU HOBEDeOmECOare 146 
SURES OAL, VIG Soe Se Sace ss ceSC0e CO0500 cba g BoD DOBEeUEeoe 149 
PAS CURTSLUIEMUTACOLES ss Walnitteee saiel Soteia aie aiaeetes con a\ociciaisie! skiwisie'as wi~iaaincie 151 
nehmuus conuius., Creplitives. gece ess = Avae winisenctsnc = oe ewes So's o-t = 155 
Selerostoma hypostomum, Diesing 2. 5.< s-- 2. -- 20 cece ce vsece eseeee 161 
The nodular disease of the intestine, W@sophagostoma Columbianum,n.sp — 165 
PanCROCEpialus Gjeis TUG eam ea eae escasscceek ese scceec- 181 
Parasites of the lungs: 
introductonryeremankapeesseeeeearts sess ae cies sie aa ees = clea tela ota oiser= 185 
The hair lung-worm, Strongylus ovis-pulmonalis, Diesing .------- ------ 156 
The thread lung-worm, Strongylus filaria, Rud ..---.---.---+---+---- 201 


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XIII. 


XIV. 
XV. 
XVI. 


XVII. 


XVIII. 
XIX. 


XX. 


XXI. 


XXII. 


XXIII. 


XXIV. 
XXV. 


XXVI. 


XXVIT. 


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XXIX. 
XXX. 
XXXI. 
XXXII. 
XXXIII. 
XXXIV. 
XXXV. 
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INDEX OF ILLUSTRATIONS. 


Gonris ObUD, MUN) Bae seocouecocjes5o5 co eocoEaSccogaccoono 
Cstrus ovis, in sinuses of the head ..--.-.----------- Site, Hs oe 
(strus ovis, in nasal cavity and sinuses of the head -... .--- ; 
Melophagus ovinus, Linnzus.....-:.....---. ------ ------ ---- 
Trichodectes sphewrocephalus, Nitzsch ....-..----.------+----- 
Trichodectes limbatus, Gervais, et T. climax, Nitzsch...--.-.-- 
Psoroptes communis, Fiirst., var. ovis. Adult ..---.----.---- 
Psoroptes communis, var. ovis. Young .--------------------- 
Tenia marginata, Batsch .---- BO aR Sb COS EROS Donn oo oaeeoeiee 
Tenia marginata, in the liver .-----.---- Sea etahe Sarees aes nee, 
Tenia tenella, Cobbold, T. cenurus, Kuchenmeister, et T. ech- 

inococcus v. Siebold....---.------ aa Moser sae eles tot ek 
Tenia fimbriata, Diesing -.----- .-----------------<-- BDSECEC 
Tenia fimbriata, original figures of Diesing ..--.------------ 
Tenia expansa, Rudolphi. Adult.........--.--------------- 
Tenia expansa, young stages.-..-...----.----------- ------- 
Distoma hepaticum, Linnzus....---..----.------ ------+----- 


Linguatula taniodes, Rudolphi, Amphistoma conicum, Zeder, 

et Distoma lanceolatum, Mehlis ..---...-----.----.-------.- 
Strongylus contortus, Rudolphi.-.-.-.----------..----------- 
Strongylus filicollis, Rudolphi ...------.---------------+----- 
Strongylus ventricosus, Rudolphi...-..-..---.---------------- 
Ascaris lumbricoides, Linnzeus ....--..------ ~<<«--..-------- 
Dochkmiuscernuus, Crepe ons esse= occ ces <<< se = 
Sclerostoma hypostomum, Dujardin...--..------------------- 
(Hsophagostoma Columbianum, Curtice. Adult ..---.-------- 
(Esophagostoma Columbianum, young stages. .--.--.---------- 
(Esophagostoma Columbianum, in the intestinal coats -..----- 
(@sophagostoma Columbianum, in the intestinal coats..------ 
Trichocephalus affinis, Rudolphi.......---------------------- 
Strongylus ovis-pulmonalis, Diesing ..---..----------+------+- 
Strongylus ovis-pulmonalis, in the lungs...-..----.----+---- é 
Strongylus ovis-pulmonalis, in the lungs. ..-..---------------- 
Strongylus ovis-pulmonalis, in the lungs...-.-.----- +--+ ----- 
Strongylus ovis pulmonalis, in the lungs ..---.-------------- 
Strongylus filaria, Rudolphi- -....--..----------------+----- 
Strongylus filaria, in the lungs ....-.------------ SS eee 
Strongylus filaria, in the lungs ..-.-.-..----------+-----++---- 


LETTER OF TRANSMITTAL. 


WASHINGYLON, D. C., April 21, 1890. 

Sir: I have the honor to submit herewith a report upon the para- 
sites of sheep, which has been prepared with much care and will prove 
of permanent value to all owners of this class of our domesticated ani- 
mals. The information heretofore attainable on this subject in the 
United States has been fragmentary and in many cases unreliable, 
although the parasitic diseases of sheep are among the most frequent 
and serious maladies by which this species of animals are affected. 

It has been the aim in the preparation of this volame to make the 
descriptions and the illustrations so plain that any one‘will be able to 
identify the parasites which he may find in his flock, and yet the sub- 
ject is in some of its aspects so technical that it could not be presented 
entirely in popular language. The technical descriptions which it is 
deemed necessary to insert have, however, been placed in small type, 
and those not interested in the characters by which the species are 
identified can omit such paragraphs. The symptoms and appearances 
presented by diseased animals and the treatment of the diseases have 
beenggiven at considerable length, and these will be read with interest 
by all who desire information on this subject. The illustrations are < 
prominent feature of the work, having been drawn and lithographed 
with the greatest care, and every attention given to make them acecu- 
rate in their most minute details. Nearly all of these are original and 
were drawn from nature. 

The nodular disease of the intestines, together with its cause, is de- 
scribed for the first time in these pages. This disease is common and 
wide-spread, but its cause and nature were mysterious until they were 
discovered through the investigations of this Burean. We have here 
once again a demonstration of the value of systematic, scientific in- 
vestigation of the diseases of animals, for the results obtained by the 
study of this malady are among the most interesting contributions of 
modern research. The facts obtained in the investigations of the fringed 
tape-worm and the hair lung-worm are also of more than ordinary in- 
terest. 

The subject of parasites and parasitic diseases is one of great impor- 
tance, and must become more prominent as the number of domesti- 
cated animals in the country increases and the pastures become more 

7 


8 


limited in comparison with the flocks which graze upon them. Under 
such conditions parasites multiply more rapidly, and their ravages be- 
come more alarming. For this reason the time has come when we must 
pay more attention to these organisms and study more assiduously the 
means of controlling them, if we would preserve that healthfulness and 
vigor for which the animals of this country have heretofore been noted. 
It is hoped that the systematic treatment of the subject presented in 
the accompanying volume may assist in accomplishing this object. 

Very respectfully, 

D. E. SALMON, 

Chief of the Bureau of Animal Industry. 
Hon. J. M. Rusk, 

Secretary of Agriculture. 


ANIMAL PARASITES OF SILEEP. 


GENERAL REMARKS. 


In 1782, Goeze, a distinguished German naturalist, wrote: ‘“‘Among 
all mammals except the horse, the sheep appears to be most harassed 
by worms.” He thus called attention at that early period to the great 
abundance of ovine parasites, an abundance which have transmitted 
their posterity in comparatively undiminished numbers. 

The presentation of all the facts now known concerning these para- 
sites, their structure, their life histories, the injuries they cause, and 
the methods of prevention and treatment, together with such new ma- 
terial as may have been learned concerning them, needs no apology to 
the sheep owner, for he is alive to the fact that the majority of his losses 
is due to these parasites. The sheep industry of the United States 
embraces the product of 42,599,079 sheep, valued at $90,640,369.* De- 
pendent on these sheep and their products are an army of menand their 
families, from the flock-master and his help to the consumers of the flesh 
and the manufacturers of the fleece. Add to this the value of the plant, 
which is dependent on the sheep industry in all of its ramifications, and 
there results an accumulation of many millions of dollars, a value which, 
from a business stand-point alone, should cause the Government to 
foster and to protect it from every source of injury. 

As the whole growth of the industry is dependent on the health and 
vigor of the sheep, it follows that whatever tends to produce a better 
condition or ward off threatening disease from them is for the benefit 
of all interested in and dependent upon the success of the industry. 
The parasitic diseases —those produced by the animal parasites of 
sheep—are, if we may judge from observation and the letters of inquiry 
directed to this Bureau, the chief source of losses, and ifin any way this 
bulletin may result in promoting a better knowledge of these too little 
known pests, and in teaching facts which will lead to better care and 
treatment of the flocks as regards hygienic prevention of diseases, the 
cost and labor laid out upon the work in its various details will be well 
expended. 


Particular attention has been devoted to illustrating each species of 
parasite, and, so far as possible, the lesions of the disease produced by 


* United States Department of Agriculture, report on numbers and values of farm 


animals, January, February, 1889, pp. 5 and 6, 
9 


10 


it. In the illustrations of the species certain features which present 
specific differences have been constantly drawn. Peculiar features of 
anatomy and development have also been illustrated. The entire de- 
velopment of any species from the unimpregnated ovum to the adult 
form is not illustrated, but one species may show the developing ova, 
another the embryo, and still another small and adult forms, and thus 
the entire development of many of the species can be well understood. 
Especial attention has been devoted to representing certain organs of 
economic importance, 7. ée., those organs which are immediately con- 
cerned in injuring the tissues of the sheep. The majority of the draw- 
ings were made from nature by Mr. W.S. D. Haines, and the others by 
Dr. George Marx, both artists connected with this Department. The 
excellence of their work shows for itself. Where material for original 
illustration has been unavailable, figures chosen from the leading 
text-books on the subject under consideration have been copied, and 
due recognition of the source acknowledged in the description at- 
tached. For the accuracy of these drawings the author alone is respon- 
sible. He believes that all the anatomical details are accurate, but such 
is the difficulty of seeing the minuter details that some of the latter are 
omitted. As their presentation belongs properly to a more specific 
investigation than this their absence will scarcely be noticed. It has 
been the constant endeavor of both the artists and the author to make 
technically perfect drawings, and at the same time present the subject 
so clearly to the eye that not only a novice may, by the aid of a small 
magnifying glass, be able to determine the species, but that the scien- 
tist may also use the work profitably in subsequent investigations. 

The text devoted to each species is intended to contain a general 
description of the parasite, its life history, the way it causes disease, 
the disease produced and mode of treatment, both preventive and re- 
medial. Many of the specific descriptions are technical. To the be- 
ginner, who can identify the species by careful comparison with the 
figures, these are unnecessary, but as he advances in their study the 
meaning of the technical descriptions will become more apparent and 
useful. In a work of this character such technical specific descriptions 
are unavoidable. To the scientist they are absolutely necessary. 
Wherever possible the complete life-history of the parasite is described 
and illustrated; unfortunately, however, the species whose life-histories 
are positively known are too few. Although the life-histories of the 
majority of the worms seem very evident, still the evidence upon which 
they are based is not deemed entirely conclusive by scientists. So skep- 
tical are the majority of this guild that rigorous proof alone seems to 
satisfy them, and this is particularly the case when the views set forth 
in regard to either of the species are at variance with pre-existing 
opinions. 

Rigorous demonstration of the various stages in the life-history of a 
parasite demands that its eggs or embryos shall be fed to an uninfected 


11 


host (sheep in this case), and the parasite be found in it subsequently, 
at a stage of growth corresponding to the time which has elapsed dur- 
ing the experiment. The conditions necessary for raising embryos, for 
procuring uninfected sheep and for keeping them from outside sourees 
of infection, are many and difficult to fulfill. Up to the present time, 
with few exceptions, infection has been secured in the experiments only 
by excluding or regulating certain of the conditions surrounding sheep. 
These conditions are such that, although the problems in each case 
have not been absolutely proven, there is much probability that the life- 
history of most species is well determined. In describing the injury 
wrought by the parasite and the resulting disease, technical descrip- 
tion has been avoided as much as possible, in order that the work may 
be rendered more valuable for farmers and ranchmen, who have but a 
limited knowledge of the terms used in medical literature. ‘These de- 
scriptions are, on this account, necessarily imperfect from a scientific 
point of view, but it is hoped none the less efficient for the purpose- 

A careful study of the various diseases will show that the irritations 
set up and the lesions resulting therefrom are mainly due to mechan- 
ical causes, whatever be the organ attacked. Certain of the dis- 
eases, however, seem to be aggravated by nervous or reflex irritation 
induced by the parasite, while others are hastened by a loss of blood or. 
nutritive material abstracted from the host by the parasites. 

The diagnosis of parasitic diseases is always determined by finding the 
parasite or its eggs. The quickest and surest determination for inter- 
nal parasites is made at a post-mortem examination. For intestinal 
parasites many authors recommend the examination of thedung. This 
method has not been verified by experience, but appears to be tedious 
and difficult, and a method better adapted to experts than layman. 

There are certain symptoms from which one may infer that sheep are 
infected with parasites. A large part or all of the flock is affected and 
the symptoms shown by the different individuals are similar. The ap- 
petite is generally good, but individual members present a poor, stunted, 
hide-bound, bloodless, big-headed, pot-bellied appearance. Other local 
symptoms, depending on the organs affected, are present. The most 
positive characteristic is to find that a number of sheep raised together 
are affected in the same way. From these general symptoms those de- 
pending on climatic changes, and irregularity or insufficiency of food 
and water, mustof course beexcluded. The sheep owner who discovers 
weakness among his lambs should not wait until one of them dies before 
he endeavors to make a diagnosis, but should undertake to diagnose the 
disease in the earlier stages by sacrificing one or more of the worst 
affected, and thus gain time in treating and preventing the extension of 
the disease. By waiting for the disease to develop he allows the lambs 
to grow poorer and weaker, and when action is finally undertaken it is 
upon patients which are, in many cases, already too weak to stand 
vigorous treatment, aud which can in no way profit by preventive 


12 


measures as they should. The lambs examined can, if the meat is not 
too poor and watery, be used on the table without harm to the consumer. 
If the animals are at all feverish, as is the case in the later stages of 
disease, the carcasses should be thrown away. It is in the beginning 
of the disease that treatment, both hygienic and medicinal, is needed 
and produces its best results, and therefore an early diagnosis and de- 
termination of the malady is fully as essential as in the more virulent 
bacterial scourges. 

Though the treatment advised in a work of this character should be 
its strongest point, yet it is to be regretted that such is the state of 
knowled ge of the life-history of these parasites and of the practical re- 
sults of medicines used in combating them under the conditions in 
which sheep are held on the pastures, that it is felt that this field is yet 
to be properly entered and worked up from an experimental stand-point. 
The subject appears, as yet, to be in an empirical stage. Although the 
best recipes have been compiled and presented, they appear to be old 
and hackneyed to one who has been enabled to trace the same recipes 
from book to book. Indeed, some of those presented, which contain 
inherent virtues, come from countries where sheep-ranching is unheard 
of, and seem to be sufficient only in the closely settled communities 
where labor is cheap and where time can be devoted to saving property 
even though the value is not great. The medical treatment of large 
flocks should be investigated from a broader stand-point than any yet 
taken. Our insufficiency of knowledge on these points arises from the 
small value of single animals and the hesitation of people to seek the 
aid of skilled veterinarians until they find that they are unable to treat 
the disease themselves. The great benefit in doctoring animals whose 
individual worth is but a few dollars lies in the treatment of numbers 
at a time, and in making an early diagnosis of the disease. Those who 
have large and valuable flocks should watch their lambs for the earli- 
est symptoms, and then if there is a skilled veterinarian available ob- 
tain his services. Oftentimes the family doctor can and will give advice 
that will materially assist, for his knowledge of other diseases, their 
symptoms and lesions, and of the use and effects of medicines, make 
him the most available authority in the absence of the veterinarian. 

Upon the hygienic treatment, %. e., upon the care and attention the 
flock receives, depends in great measure its health and good condition, 
and the prevention of the parasitic diseases. It is out of the province 
of this bulletin to discuss the proper housing, food, and drink of sheep, 
beyond what is required for the prevention of parasitic maladies. The 
chief necessity as regards buildings and yards is that they should be 
kept clean. Periodic cleansings of wood-work and floors should be 
sufficient. Whitewashing and the liberal use of lye water for cleansing 
wood-work are desirable, and in some diseases, such as scab, absolutely 
indispensable. In the care of yards an economic management of the 
manure is to some of prime importance. It would seem that a mixture 


13 


of this manure with lime in the compost heap, and a frequent cleansing 
of the yard, would be far better, so far as the sheep are concerned, than 
to allow it to accumulate. The lime would not only serve to kill the 
eggs of parasites in the manure, but would add fertilizing material to 
it. Manure so treated would be a better fertilizer, and would also be 
less apt to infect sheep when spread upon the fields. The compost 
heap should never be where the liquor from it can be washed by the 
rains into water which the sheep drink. As the manure from these 
yards may prove the source of infection, sheep should never be pastured 
on fields recently enriched with it, unless there is absolute certainty 
that the previous treatment of the manure has destroyed all the em- 
bryos of the parasites. As frequently urged in the text, every means 
should be taken to supply sheep with pure water. Although experi- 
ments show that sheep have other means of getting parasites than from 
the water they drink, yet this is at times a very fertile scource of infec- 
tion. The use of drinking-troughs into which water runs or is pumped, 
and rapidily running water, seem best suited to meet the requirements. 

The grain food should be fed from cleanly swept troughs or floors. 
Hay should be put in racks, as feeding from the ground is not only 
wasteful but tends to infect with parasites. Salt should be supplied in 
boxes placed where sheep can have ready access to it. The mixture 
of a small proportion of finely powdered sulphate of iron with the salt 
is allowable at times. 

Pastures, which are ordinarily uncared for further than to provide 
fences for securely confining the sheep, need careful supervision. Wet 
swails, bogs and swamps should either be fenced out or drained. Past- 
ures which are overstocked, and in which a flock of sheep is kept con- 
tinuously, are the most fertile sources of infection. Not only do the 
sheep become more frequently infected where they are compelled to eat 
the grass close to the ground, but the chances of their being compelled 
to graze on an infected area are largely increased by keeping them 
ranging over the same ground of limited area week after week. Old 
sheep stand such treatment much better than young ones. For the lat- 
ter, those fields which have not been pastured on by older sheep are 
better. The practice of feeding the sheep over fields from which the 
crops are removed is a good one, not only for the sheep but for the 
fields. These remarks, of course, apply more strictly to fenced farms 
and not to unfenced sheep ranges, but even on these certain portions 
of the range can be reserved for the lambs. The practice of allowing 
lambs, after they are old enough to wean, to feed after older sheep is 
also a source of infection. 

The relation of the dog to sheep husbandry is too important to be over- 
looked. Were it not that the definition of parasite excludes such ani- 
mals as can be considered beasts of prey, the dog would be placed at 
the head of the list of parasites as being the most destructive. Though 
this be unmistakably apparent to a large majority of sheep-owners, 


14 


there are many who believe that the dog is man’s most faithful friend 
and that he is of great use even on a sheep farm. It is unfortunate for 
the dog that the mass of testimony on this subject is against him. It 
is not from the stand-point of the dog as a beast of prey, how=ver, that 
this work is written, but it is from the more technical stand-point of the 
dog as a carrier of parasites dangerous to sheep and man. In tne list of 
parasites of sheep there are at least four which are common to the dog 
and sheep, viz: Tania marginata, Batsch; 7. cenurus, Kiich.; T. echi- 
nococcus, V. Siebold, and Linguatula taenioides, Rud. The last is rare, 
and in justice to the dog should not be used against him, although it 
may subsequently afford as damaging evidence as the other species. 
By referring to the descriptions of the other three species it will be 
found that dogs harbor in their intestines the adults of these species, 
and that they scatter the eggs of the parasites broadcast for the infec- 
tion of sheep. Thus each dog, harboring one or more, is a constant 
menace to the health and lives of the flocks in the neighborhood. Nor 
is this all, for man himself can be infected by at least two of these spe- 
cies—Twnia echinococcus and T. marginata—in their cystic stage. The 
former of these species produces a disease of slow development, but one 
which is nearly always fatal in results. To prevent these diseases the 
precautions prescribed in the text must be closely adhered to. A plan 
which would remove much of the loss caused by dogs by doing away 
with them entirely is scarcely practical in this country, where the ma- 
jority of these animals are owned by persons who have no direct inter- 
est in sheep. The hunting and the sheep dog are most to be feared, 
unless we except some of the fiercer watch-dogs which are kept at 
slaughter-houses and fed on waste bits. The day of the usefulness of 
hunting dogs is quite past, and their retention by sheep-men at least 
should be abandoned. The watch-dogs are nearly always chained and 
in places not accessible to sheep. 

In the range country the coyotes and prairie wolves still menace the 
flocks by killing individuals for food, and by harboring the adults of 
Tenia marginata and T. cenurus, the eggs of which they also scatter. 
In most sections, especially where a bounty is offered for their scalps, 
the trap is remorsely exterminating them. Laws which would subject 
the mongrel curs to the same treatment would result in a great gain to 
the farming community and to their respective owners, if they be owned 
by any one. 

There are reports that the sheep can be infected by parasites from 
some of the many wild animals that still haunt the land where they 
were formerly so abundant. The examination of these little quadru- 
peds to ascertain the parasites they contain has not been as extensive 
as it should be for a broad generalization, but so far as it has extended 
it is safe to say that sheep are not infected from either rabbits, skunks, 
squirrels, woodchucks, gophers, prairie dogs, or foxes. Foxes may 
harbor some of the adult Tenia whose cystic stages infest sheep, but 


15 


unless they can obtain the young forms of the parasites by eating the 
viscera of sheep they would be very unlikely to be infected with adults. 
It is also reported that rabbits harbor the cystic form of Taenia margin- 
ata; but this statement has not been corroborated, as the rabits ex- 
amined contained the evstic form of 7. serrata. If rabbits should be 
proven to harbor the cysts of 7. marginata then the danger would 
arise, not from them, but from hunting-dogs which eat the rabbits and 
the cysts they contain, and harbor the adult parasites that alone are 
the source of danger. The possibility of infection by parasites from 
deer is too small to be considered as an economic question, owing to 
the great scarcity of these animals. The antelope (Antilocapra ameri- 
cana, Ord.) may be a bearer of many of the same species of parasites as 
the sheep, but they also are becoming too few to be considered as < 
source of danger. In short, it is futile for the floekmaster to consider 
these sources at all while his own flocks are infecting his fields, and his 
dogs are constantly assisting them. Could these sources of infection 
be controiled, there would be no need for him to regard the wild ani- 
mals as his enemies. 

In purchasing sheep particular attention should be paid to the gen- 
eral appearance and past history of the flock from which the purchase 
is made in order to avoid parasitic diseases. Before adding recent pur- 
chases to flocks they should all be thoroughly dipped to kill external 
parasites. If they are coughing ever so slightly, the cause of the cough 
should be investigated to determine the presence or absence of lung 
worms. If some are hidebound or weak after allowing for the charac- 
ter of the season and the condition of pasturage the possible presence 
of intestinal parasites should be next considered. It is not very prob- 
able that there are any farms free from all parasites, but there are many 
that are free from a considerable portion of the species which are prop- 
erly parasitic on sheep. Purchasing here and there in making up a 
flock brings all sorts of parasites together, thus infecting afarm to such 
a degree that it is difficult to get rid of them. 

The medical treatment must, of course, be specially adapted to the dis- 
ease. The treatment of external parasites is effective, and well repays 
all efforts. The treatment of internal parasites may be divided in gen- 
eral into treatment for lung worms, for intestinal worms, and for liver 
worms. The last is by far the most unproductive of good results. Par- 
asites situated elsewhere in the sheep do not readily yield to medical 
treatment. 

Scab is the only parasitic disease that has been thought worthy 
of legislation. There are others that demand as serious considera- 
tion, but their importance has not yet been fully presented to the 
public. Little attention has been given to police interference in the 
management of these diseases. No doubt such interference might be 
profitably pushed further than it is in this country, especially with 
regard to scab. Not only should the highways be guarded against the 


16 


movement over them of scabby sheep, but a competent imspector 
should be appointed by the State to supervise every sheep dipping, to 
compel the dipping of every scabby flock, and to attend to the renova- 
tion and disinfection of the sheep-yards and walks. Every band of 
scabby sheep is a constant menace to the health of others. In this 
country there seems to be no sheep disease produced by animal para- 
sites which renders the flesh harmful to man, further than that some 
of the flesh may be less nutritious. Until the sale of meat of all kinds 
is guarded by more stringent regulations there does not seem to be any 
reason for urging police restrictions on the sale of meats of the inferior 
quality which some of these diseased lambs undoubtedly furnish. 

There are described in this volume twenty-six species of animal para- 
sites of sheep, as follows: 


1. Estrus ovis. 14. Distoma hepaticum. 

2. Melophaqus ovinus. 15. Amphistoma conicum. 

3. Trichodectes spharocephalus. 15. Distoma lanceolatum. 

4. Trichodectes climac. 17. Strongylus contortus. 

5. Trichodectes limbatus. 18. Strongylus filicollis. 

6. Psoroptes communis. ~ 19. Strongylus ventricosus. 

7. Linguatula tenioides. 20. Ascaris lumbricoides. 

8. Tenia fimbriata. 21. Dochmius cernuus. 

9. Tenia expansa. 22. Sclerostoma hypostomum. 
10. Tenia marginata. 23. @sophagostoma Columbianum. 
11. Tenia tenella. 24. Trichocephalus affinis. 

12. Tenia cenurus. 25. Strongylus ovis-pulmonalis. 
13. Tenia echinococcus. 26. Strongylus filaria. 


Of the species described three genera—Melophagus, Trichodectes, and 
Psoroptes, embracing five species, M. ovinus, T. spherocephalus, T. cli- 
max, T. imbatus, and P. communis—are external parasites. 

The species which there is reason to think do not occur in this coun- 
try are Tenia tenella and Amphistoma conicum. The former is consid- 
ered by continental authorities as a synonym of T. solium or T. margi- 
nata. The writer has not found Linguatula tenioides, Tenia cenurus, 
T. echinococcus, Distoma hepaticum, or D. lanceolatum in sheep, nor 
learned from authentic sources of any of these occurring here except D. 
hepaticum. The other species may eventually be found, but they will 
probably be rare. One other species, Ascaris lumbricoides, seems to 
be a rare one in sheep. _The remaining species are all more or less 
abundant. Tenia fimbriata and (sophagostoma Columbianum seem to 
be exclusively American species. The others are common to all parts 
of the world where there are sheep. Von Linstow (Compendium der 
Helminthology, 1878), catalogues nineteen species of internal parasites 
which infest European sheep. One of these, Monodontus Wedlii, Molin, 
is a synonym of Dochmius cernuus Creplin; another, Nematoideum 
ovis, Diesing, is a lung-worm insufficiently described. Still another, 
Trichosoma papillosum Wedl., isa synonym of Strongylus jfilicollis, Rud. 
The remaining sixteen species are described in this volume. There are 


17 


two lung parasites of sheep in the Old World that have not been found 
here, viz: Strongylus rufescens, Leuckart, and S. minutissimus, Megnin. 
The former is said to occur in Germany and France, but is so meagerly 
described that it probably is not a distinct species, but asynonym of 
Strongylus (Pseudalius) ovis-pulmonalis, Diesing. The latter occurs in 
Algeria, is well described and figured, and- seems to be a well estab- 
lished species. Strongylus ventricosus, also a European species, has 
not, to my knowledge, been described as a parasite of sheep heretofore. 

A further comparison of the above list with those of parasites of sheep 
in other countries is re-assuring, because, first, native sheep have now 
nearly all the parasites that they can acquire in this country; second, 
that although nearly all the European species have been imported, Dis- 
toma hepaticum, L., the liver-fluke, Tania .echinococcus, v. Siebold, and. 
T. cenurus, Kiich., are either very rare or else do not exist in this coun- 
try. These three parasites have been the cause of great loss among 
sheep in other parts of the world. 

The comparatively long list of parasites furnished will seem to the Eu- 
ropean to indicate that sheep in this country are more infected than 
those in Europe; but in this connection it should be remembered that 
much time has been spent in hunting for several of these species, and 
some of them are rare, inconspicaous, and do little damage. 

The following is a list of our mest destructive ovine parasites: 

Hstrus ovis, L.; Psoroptes communis, Fiirst.; Tania fimbriata, Diesing; 
T. expansa, Rud.; Strongylus contortus, Rud.; Dochmius cernwus, Creplin; 
(Hsophagostoma Columbianum, Curtice; Strongylus ovis-pulmonalis, Dies- 
jing; and NS. filaria, Rud. There are nine species in all, a list which 
compares favorably with that of the ovine parasites of any other coun- 
try ; for all but two species, 7. fimbriata and O. Columbianum, are coin- 
mon to all countries, and these two are more than offset by the preva- 
lence of more destructive parasites in the Old World. 

On the whole, the flockmasters of the United States may be congrat- 
ulated on the good condition of their flocks and their comparative free- 
dom from both external and internal parasites. 


PARASITISM. 


Definition.—The animal parasites of sheep are those which live in or 
upon their living bodies and obtain nourishment from them. The term 
‘animal parasites” is used in order to distinctly separate this group 
from the vegetable parasites which attack the living organs of sheep. 
Both animal and vegetable parasites prey upon the flocks and cause 
disease, but such are the differences between them, their effects and the 
methods of investigating them, that an investigation of either forms a 
large field of research. 

Parasites as defined above include a large number of animals so dif- 
ferent from one another that parasitism is the only common character 

23038 A P 2 


18 


which groups them together. Though this distinctive feature is suffi- 
cient for the present purpose, it is a very variable character, for the 
degree of parasitism manifested by each of the species varies through 
all the scale possible from the transient momentary parasites to the 
permanent. 

The animal parasites of, sheep are all embraced within three great 
branches of the animal kingdom: The Protozoa, Vermes, and Arthro- 
poda. None of the first branch, which includes the Coccidia and Bal- 
biana gigantea, Raillet, are described in this volume. Examples of the 
second, which includes all the worms, and of the last, which includes 
the insects, mites, and linguatula, are abundant. 

The worms live, as a rule, in the open cavities of the body—in air 
spaces of the lungs, the ducts of the liver, and the lumen of the intes- 
tine. The exceptions to this rule arise from those immature forms 
which penetrate into the substance and closed cavities of the bodies, 
e. g., the bladder stages of the tape-worms and the young embryos 
of Gsophagostoma. The worms are called internal parasites. It is 
easily understood, however, that being held in the cavities of the body 
which have communication with the exterior, they are really external to 
the body tissues, and only those embryonic forms which penetrate into 
the tissues of the infested animal or host are true internal parasites. 

As a rule the insects live on the surface of the body. They are 
called external parasites. The exceptions are the larva of @strus ovis, 
which lives in the nasal cavities, and Linguatula, whose young stage 
infests various organs of sheep. M/strus is usually classed with the 
external parasites, and Linguatula is in sheep truly internal. As has 
been stated, those parasites which in their young stages penetrate the 
tissues of sheep are alone true internal parasites. Even these spend 
their adult stages in the open cavities of some other host and then be- 
come true external parasites, so that no one of these parasites is, strictly 
speaking, an internal one throughout its life. That every parasite 
should be an external one in its adult stage is a necessary condition of 
its existence and of the perpetuation of its species, for it is only in the 
open cavities that they can obtain sufficient air and food, and can mate. 
From these cavities, too, the eggs and young can eseape for the infec- 
tion of other sheep. The facility offered for mating and distribution 
is the most important reason. In order to avoid confusion of terms 
those parasites infesting the surface of the body will be called, in con- 
formity with custom, external parasites; the others, which inhabit the 
tissues of the body and its cavities, internal. 

Though the animal organisms that infest the living bodies of sheep 
be small, they are endowed with all the vital functions of life. Allcan 
move, feed, feel, and reproduce. None of the worms can see or hear. 
The insects are more highly specialized than the worms. All of them 
have in the past become so adapted to their surroundings that they can 
live in no other, and while sheep thrive better if not infested by para- 


19 


sites the latter can not live without sheep. The only exceptions are 
those species which are also parasitic on other animals, as goats and 
cattle. The modifications of organs which have arisen out of the needs 
of parasitism are too many to givein detail. The great central fact of 
their lives is that all the parasites have arisen from their kind, and under 
favorable circumstances will reproduce their species, and that they are 
to be treated as the originators of disease and not as the products of 
disease. 

The methods by which sheep become infested differ with the species. The 
external parasites are usually transmitted by actual contact of sheep 
against sheep. The parasites may, however, be dislodged from their 
former host and afterwards make their way to another sheep. The first 
is known as mediate, and the second as immediate contact. The dis-. 
eases produced by the external parasites are true contagious diseases, 
and should be regarded as such fully as much as any of the more act- 
ively virulent maladies. The transmission with this class of parasites 
is usually an active one; they may, however, be borne from one sheep 
to another by people, cattle, goats, or by locks of wool, when the trans- 
mission would be passive. 

(Hstrus ovis, which seems to bridge the gap between the external and 
adult internal parasites, differs from these groups in being able to act- 
ively infest its host with its young, without an actual contact or inter- 
mediate bearer. Lice, louse-flies, and scab insects may do this in a 
less degree, butnot to that possessed by the @strus. The Wstrus larvae 
are never transmitted by contact; they must mature, fall to the ground, 
metamorphose, and emerge as adults before the females can infect sheep. 
The internal parasites are passively conveyed into sheep along with 
the food and drink consumed, and never actively enter into the trans- 
mission. They may be conveyed either as eggs or very young embryos. 
(@strus forms the single exception. 

The terms “ contagious” and “infectious” can be applied to these 
parasites. The former is applicable to those parasites which usually 
transmit themselves to other hosts, the latter to those which are trans- 
mitted to their hosts along with food and drink. The young of (strus 
have no agency in their transmission, and hence infect sheep. 

Parasites are frequently said to invade the hosts which harbor them. 
This is only true of those species which actively undertake migration, 
as-scab insects and sheep ticks. A few species invade the organs of 
their hosts after the latter have been infected, thus: The larvee of @strus 
crawl from the margins of the nostrils to the sinuses of the head; the 
lung worms migrate into the lungs; the young embryos of Tenia mar- 

_ginata tunnel the liver; T. cenwrus tunnels the brain; sophagostoma 
penetrates into the intestinal walls. Those internal parasites which 
undertake active migration in the bodies of their hosts seem to form a, 
minor class in the parasitic world, those which lodge in the intestine 
and ducts emptying into it forming the majority. 


20 


The ability to select their final lodgment belongs to each species, and 
is the one character on which their own life and that of the species de- 
pends. This is self-evident in the case of external parasites. After 
hosts are once infected by the internal parasites and the young embryos 
are endowed with activity, they either select their proper place while 
being carried along by intestinal fluids, or force their way to it through 
all opposing tissues and against all counter currents of fluids. Those 
embryos which fail to reach these places finally die for want of the nec- 
essary conditions of life. The very ability that is so absolutely neces- 
sary to enable certain of the parasites to reach their chosen organ often 
proves the means of their premature death. Tania marginata cysts 
invading the liver become lost in the mass of this organ and perish. 
Multitudes of these parasites injure the capsule of the liver and cause 
the sheep invaded to die long before they have matured sufficiently to 
pass into dogs. The embryos of G/sophagostoma often wander into the 
mesenteries, the retro-peritoneal glands and liver, and perish. 

Parasites escape from their ovine hosts either actively, e. g., the 
young and adults of the louse-flies, lice, mites, and the larvee of Gstrus, 
or passively as eggs or young embryos, the young embryos of the 
Strongylus filaria and Tenia expansa, the completely segmented eggs of 
the Strongylus contortus, and as eggs incompletely segmented. In 
the latter case they are rejected with the excreta of the lungs or intes- 
tines. A very few (the cystic tape-worms) escape only after the death of 
their host by theintervention of some carnivorous animal which swal- 
lows them with its food and liberates them from their imprisonment by 
the processes of digestion. The death of the host is usually caused by 
the carnivorain search of their food. The continuance of the parasites’ 
life into the adult stages depends, therefore, on the destruction of their 
host. This fact is contrary to the usual rule of parasitism, which de- 
mands that the host continues to live in order that the parasite may 
live and reproduce its species. 

The length of time and the stage of development at which parasites 
infest their host varies considerably. Lambs have no parasites at birth. 
Within a month or two after, they become infested by a few individ- 
uals of certain species of round worms, and by external parasites. 
From this time on they may harbor any of the species to which they 
become exposed. It will be noticed that the commencement of infection 
begins when the lambs first nibble grass. The louse-flies, lice, and scab 
insects infest the fleeces and skin from generation to generation. Unless 
it should subsequently be proven that the hair-lungworm (Strong- 
ylus ovis-pulmonalis), and the stomach round worm (Strongylus contortus), 
may also perpetually infest sheep, they harbor no other species through, 
out their entire life cycles. Mstrus ovis is parasitical only in its larval 
stage, and consumes months indeveloping. Becauseit can not take nour- 
ishment when adult, it is believed to pass a very ephemeral adult stage. 
The broad tape-worm develops rapidly and disappears, its six-hooked 


21 


embryo apparently spending long seasons of suspended life functions 
on the ground. The fimbriated tape-worm develops more slowly, con- 
suming the greater portion of the year; its embryos may exist on the 
ground for indefinite periods. The cystic tape-worms pass indefinite 
periods as cysts in sheep, depending on their resistance to the vital 
forces of the organs infested and upon the date of their liberation from 
imprisonment. The life cycle of the liver flukes seems to be completed 
ina few months. The majority of the round worms seem capable of 
withstanding the elements while scattered over the pastures for indefi- 
nite periods, either as ova or partially and completely developed 
embryos. Their cycle of life in sheep is of variable periods, depending 
on the species. Ulsophagostoma, some of whose embryos invade the 
intestinal wall, offers a retarded development lasting through months. 
Other species develop more rapidly. The exact cycle for each species 
has not been determined, but most of them become adult in less than 
six months, some in less time than three. 

The seasonal appearance of each species depends on its life eyele, 
the average temperature and the humidity of the season, and the age 
of the lambs. Spring and fall seem to offer the most outbreaks of dis- 
ease produced by parasites. Summer and winter also have their spe- 
cial parasitical diseases. Sheep-ticks, lice, and scab are more prevalent 
in winter when the sheep are closely herded in yards or barns, and when 
they are covered with heavy fleeces. The gad-fly occurs most in June 
and July, but in milder climates it evidently flies the greater part of 
the year. The disease it develops is more prevalent in older sheep, 
yearlings being the youngest that show distinct signs. The broad . 
tape-worm infests young lambs early and causes their disease in a very 
few months. March lambs harbor adult worms in May and June, and 
May lambs in August. The fimbriated tape-worm also infests lambs 
early, but does not produce its worst effects until late fall and winter. 
The liver flukes generally appear first in summer and fall. The round 
worms appear in young sheep of three months and upwards. The ma- 
jority of those that produce disease develop it as they grow adult. The 
thread lung-worms (Strongylus filaria) infest lambs, and epidemics due 
to them usually occur from spring to fall. The hair lung-worm, on the 
other hand, develops slowly, and while their presence can be detected 
in the lungs of young lambs it is the lungs of old sheep which show the 
greatest amount of changes due to their invasion. As a rule warm, 
moist seasons are most favorable to their development. The climate of 
the United States so varies from North to South and East to West that 
no exact seasonal appearances of the various species can be given. Most 
of the species seem to be present in sheep in greater or less numbers 
the year round. The most important factors in the time of outbreak of 
different diseases seem to be the age of the hosts and the cycle of life 
of the parasite. 


22 


The destructiveness of each species is dependent on the numbers of 
the invading parasites, the organ invaded, the method by which they 
produce disease, and the age of the host. As a rule, most parasites 
produce disease by their numbers, each causing its infinitesimal amount 
of annoyance. The sheep-grub, the broad tape-worms, Dochmius cer- 
nuus, and Tenia cenurus, are notable exceptions to the rule. But 
few individuals of each of these species are found invading the organs 
of sheep. Their destructiveness depends on the character of the 
annoyance produced and on the organ invaded. <A few of nearly all 
species may infest sheep, and seemingly cause no loss, but when any 
of the factors favoring the development of either of the species appears 
they increase innumerably and destroy the lives of their hosts. 

Parasites effect injury to the health of sheep in many ways, some of 
which are very evident to all, while others are indefinable and illusive. 
The injuries effected by sheep-scab, by the hair lung-worms, and by 
(Hsophagostoma, are easily discovered; but the injuries produced by the 
tape-worms and various species of round worms can not always be de- 
tected in the intestinal walls. In these the method of determining dis- 
ease is not by testing the various organs by the microscope or chemical 
analysis, but by comparing the patient with a healthy animal of the 
same age in action, appearance, weight, etc., and by comparing the 
organs of the patient with an actual or assumed standard. In these 
ways the effects of the subtle diseases produced by the parasites are 
learned and just allowance made for their importance. 

Most parasites mechanically injure tissues. They may either force 
‘their way through soft tissues as the cysts of Tania marginata, break 
through the structure of lung tissue as Strongylus ovis-pulmonalis, en- 
ter into the intestinal walls as CYsophagostoma, or lacerate the tender 
mucous membrane as Dochmius cernuus. The adult tape-worms seem 
to irritate the intestines, derange their functions, and cause nervous dis- 
turbances. Dochmius cernuus and perhaps Strongylus contortus seem to 
abstract blood. Other round worms may live on tbe intestinal contents. 

The destruction caused by the different diseases produced by para- 
sites is varied. Scab, lung-worms, flukes, and tape-worms often destroy 
entire flocks. The ravages of other species are less patent. There is 
no doubt, however, that each causes more trouble than has yet been 
assigned to it. The least destructive of the species common to sheep in 
this country seems to be Trichodectes sphwrocephalus, Strongylus jilicollis, 
S. ventricosus, and Trichocephalus affinis. 

No rigid system has been adhered to in the succeeding pages. Nev- 
ertheless, a certain plan of arrangement and treatment will be noticed. 
The highest insects in the zoologie classification precede. These are 
followed by the Acarine or scab mites. The Helminths, embracing 
the Platoda or flat worms, and the Nematoda or round worms, follow in 
turn. A systematic classification of the worms among each other is not 
closely adhered to. It may be noticed further that such an arrange- 


” 


23 


ment permits of a second subsidiary treatment of the subject by group- 
ing the parasites together as regards the organs they infest. The vari- 
ations arising are due in part to the antagonism between the two ar- 
rangements adopted. The above plan was adopted more for conven- 
ience than for its scientific accuracy from any single point of view. 
Concluding, the author desires to give due recognition to all sources, 
from which he has drawn in preparing this work. The chief sources 
of information have been the admirable works of Leuckart, Die Mensch- 
lichen Parasiten, 1868; Raillet, Hlements de Zoologie, 1885; Neumann, 
Traité des Maladies Parasitaires, 1888; and A. E. Verrill, Parasites of 
Domestic Animals, Rep, Conn. Board Agriculture, 1870-71. An en- 
deavor has been made to mention every other source in the text. 


MEASUREMENTS. 


The following tables will assist the reader in reducing the measure- 
ments given in one denomination to those in another. 


Metric system in medicine. 


Grams 
i Gani orp ibsrmbniny COON ae Be ahaeeceeasees ase bos Hboaon obTeconibeoeeerapers 0. 06 
15) erhhos Or Sy aaNS) @ClweM s5ecqe Saas sot caaces bocooe CODnbuoeTcee ssadmasces 1. 00 
HY tee etlteT Meet Ee PO ti RUA LS eo sie sraectvinin ccpieiqeics sync c'-)sen swig cetons ne seae es 4, 00 
WonnceorMlunuidvounceved Ualsenemaen ees ses see eleneeteeietarala) cleteletale=(-1= terete = 32. 00 


The cubic centimeter may be considered identical with the gram for 
water or aqueous solutions. 


Metric system in measurement. 


Inch. 
IMIS TELS CU AIS cs setae) jsiciietecto ae arse ca cs sie esarcholnsicisis/enie's jrwacisja'e’el 39, 37 
iigcentime tervequalsyaassc sates ceo sase Sec sere ouis s oct eee oe siciers 23937). Or 2 
female heregualer Seo ooo ser see erent ie ceca cus eee done si .03937 or ys 
One-hundredbthimillimetenequals’--s--asse2>- sees eessce eee sees .00039 or xeoo 
One-thousandth miliimeter equals. ............---..----+-----++- - 000039 or z5000 
eM NE LOLSLE MUM aetse sores sre rete eo awe enee see eieae cee cia 1 nearly. 


OTHER MEASUREMENTS. 


For approximate measurements a liter (2.113 pints) may be consid- 
ered equivalent to a quart; a kilogram to 2} pounds avoirdupois. 

When graduated measures of weight or volume are not at hand, the 
flock-master may use some of the common household utensils. Pint 
and quart bottles, so called, should be tested, as they vary in size. 
The pint contains 16 ounces, or about a pound in weight. The smaller 
bottles are known as 2, 4, 6, 8, and 12 ounce bottles. Vials are quite 
common, those made to contain 1, 2, and 4 drams being most abundant. 
A set of bottles can always be obtained at the drug-store and the size 
marked on them. It is far better, however, to buy a set of graduates 
and other measures, for they are of daily use. Common tumblers con- 


24 


tain from 8to10 fluid ounces; tea-cups, about 5 fluid onces; wine-glasses, 
about 2 fluid ounces; tablespoons, half a fluid ounce ; dessert spoons, 2 
fluid drams, and teaspoons, 1 fluid dram. 

In spite of the fact that the use of the metric system has been legal- 
ized in the United States, so deeply is the old English system engrafted 
upon the customs of our people that there will necessarily be a con- 
fusion of weights and measures until the use of the former is made 
compulsory. This system is so easy to learn and so easy in practical 
application that it will certainly supersede the other in use, as it has in 
the continental countries of Europe. 


THE SHEEP GADFLY—GRUB IN THE HEAD—NASAL 
CATARRH. 


CESTRUS OVIS, Linn. 
Plates I, II, and ITI. 


The popular names of this well-known parasite of sheep convey to 
the reader its epitomized life history, long known to veterinarians 
and farmers. Though the life history is a comparatively simple one, 
there are many of its details which are not only unfamiliar to the aver- 
age Shepherd, but some of which are unknown even to those who have 
made a special study of these pests. : 

The “Sheep Gadfly,” the parent of the ‘Grub in the Head,” is, 
when flying, so small and so quick in its actions that itis very difficult 
to see, and still more difficult to catch. The greater proportion of 
specimens in coilections have been raised from the grubs, 7. e., the adult 
grubs are collected and placed in a net-covered box, the bottom of which 
is covered by a couple of inches of damp sand. «In a few minutes they 
bury themselves in the sand, and in from three to four weeks they re- 
appear as flies. 

C. V. Riley (Insects Missouri, First Annual Report, 1868, p. 161) de- 
scribes the fly (Plate I, Fig. 11) as follows: 


In this stage it looks something like an overgrown house-fly. - The ground color of 
the upper part of the head and thorax is dull yellow, but they are so covered with 
little round, elevated black spots and atoms (scarcely distinguishable withont the 
aid of a magnifier) that they have a brown appearance. The abdomen consists of 
five rings, is velvety and variegated with dark brown and straw color. On the 
under side it isof the same color, but not variegated in the same way, there being a 
dark spot in the middle of each ring. The feet are brown. The under side of the 
head is puffed out and white. The antenn are extremely small and spring from two 
jobes which are sunk into a cavity at the anterior and under part of the head. The 
eyes are purplish brown, and three small eyelets are distinctly visible on the top of 
the head. It hasno mouth, and can not therefore take any nourishment. The wings 
are transparent and extend beyond the body, and the winglets, which are quite large 
and white, entirely cover the poisers. Its only instinct seems to be the continuation 
of its kind. It is quite lazy, and except when attempting to deposit its young its 
wings are seldom used. 


The male is about as large as the female, but may be known by its 
relatively narrower forehead or space between the eyes. Catching a 
male at large would be a chance operation, for though they fly to mate 
with the females around the sheep-yards and pastures, they never make 
their presence known by disturbing sheep. 

20 


26 


Brauer (Monographie der Cistriden, p. 15) records the size of the male 
and female at from 10 to 12™™, or about two-fifths of an inch; the width 
between the eyes of the male at 1™™ or one-twenty-fifth of an inch, 
and of the female at 2.5"" or one-tenth of an inch. The length of the 
wing is 9™™, nearly two-fifths of an inch. 

Distribution.—The species occurs all over the world wherever there 
are sheep. It is now too late to learn ifit was indigenous in this country, 
but we may believe that it was introduced with the earliest flocks im- 
ported, whether in Mexico or on the Atlantic coast. Brauer, in 1863, 
stated that it had then lately been introduced into Chili, South America. 

Life history and description of larva.—The interest of the flock-master 
in this species begins when the fly buzzes around the noses of the sheep 
and deposits its young just within the opening of the nostril. Many of 
the older writers on this subject supposed that the fly deposited eggs, 
but Brauer (0. ¢., p. 154), in agreement with Joly and Dufour, pointed 
out that the genus was one which deposited their young alive. Accord- 
ing to Riley (0. ¢., p. 164) Samuel P. Boardman, of Lincoln, Ill, men- 
tioned the two following independent discoveries: John Brown, ‘ Old 
Ossawattomie,” stated in the Ohio Farmer about 1851 that he saw the 
fly drop the perfectly formed and living grub in the nostrils of sheep. 
About 1861 Dan Kelly, of Du Page County, Ill., made the same discov- 
ery, and records the fact in the Prairie Farmer, October 14, 1865. 
Boardman, in 1867, received a letter from Mark Cockrill, of Tennessee, 
who wrote of having made the discovery years previous. Riley claims 
(0. ¢., p. 165) that he obtained living maggots from a fly in 1866. 

The young larva, having been deposited within the rim of the sheep’s 
nose, soon attaches itself by means of the hooks (Plate I, Fig. 6), and 
begins to make its way upward into the nostrils. The smallest specimens 
collected by the writer are shown in Fig. 7e, natural size, and are not 
much larger than when first deposited ; for the difference between their 
size and that of eggs deposited by flies even smaller than Cistrus ovis 
is inconsiderable. These small larve are in their first stage of growth. 
They are little, white, elongated bodies, less than 2™ long, @. e., about 
one-twelfth of an inch (Figs. 1.and 2). But little of their structure 
can be seen except with a lens. They already show the division of the 
body into eleven segments, two well-defined hooks (Fig. 3a, a), and two 
minute terminal breathing pores (Fig. 4a, a). The ventral surfaces 
(Fig. 2) show the little spines which later on are to become strong 
thorns; some of the spines on the sides are relatively bristle-like and 
longer in proportion than they are later on. In their second stage of 
growth (Fig. 7c, ¢) all the characters are well defined. The skin is 
white and so translucent that the digestive organs, the respiratory ap- 
paratus, and the fine filiform nerves and their gangiia can be readily 
made out; the spines on the abdomen, the hooks, and the stigmata are 
all more pronounced. In the third stage—that of the mature larva 


27 


ready to undergo its change into a fly (Fig. 7a, a, a, and b)—the charac- 
ters outlined in its first stages have been perfected. It is this stage 
that is commonly seen by those who split open the head of an affected 
sheep. The mature grub averages over 20"™ in length and 7™™ in 
width, or about three-fourths of an inch long by one-third of an inch 
wide. Its width and length when measured depend much upon its 
state of contraction. Its back is very convex, its abdomen is slightly 
curved but generally flat, its outline is a very elongated oval, with an 
acute head and obtuse posterior end. Half-grown specimens are more 
pointed at the ends and decidedly flatter on the abdomen. From the 
young to the mature larval state there is a decided change of color. 
At first they are white and semi-transparent. They quickly grow 
whiter and soon after take on a tinge of yellow, which, as they mature, 
grows darker and darker. Then, too, on the back of every segment, 
except the first and last, a dark narrow band appears which eventually 
changes from a brown black to a dead black. These bands are rather 
narrower in front, increasing in width backward. On the side of each 
segment below these bands there is, in mature specimens, a row of dark 
dots. The spines show the same changes, at first white, then tipped with 
brown, and finally changed to black. The spines occur only on the 
abdomen and the closely adjacent edge. They all point backward and 
assist the grub in moving around. 

When the larva is mature it escapes from the nostrils, falls to the 
ground, bores into it for an inch or two, and, according to Riley (o. 
c., p. 162), contracts during the next forty-eight hours to half its for- 
mer size, becomes smooth and hard and of a black color, tapering as 
in the larva towards the head (Fig. 14). It remains in this state 
three or four weeks, or according to some authorities from fifty to sixty 
days, depending on the weather. When the fly has matured within 
the case it pushes off a little round cap, ascends from the ground through 
the hole left by the larva in its descent, and emerges into day to com- 
plete the cycle of its existence. 

The office of the fly seems to be merely to reproduce its kind. On ac- 
count of its rudimentary mouth it is unable even to eat. After emerging 
the fly crawls upon some neighboring grass or twig and rests there until 
its wings and body have hardened. During the first part of its life, ac- 
cording to Brauer (0. ¢., p. 149), it is very sluggish, sitting around in the 
cracks and crevices of the walls of sheep stalls, and is so duli that it 
must be dragged out. When placed on the hand it seldom flies off. 
This dullness vanishes as soon as the fly has reached perfection and the 
right temperature of the air comes. It is then off with a whirr, first 
vertically in the air, and then in the direction of the flocks. 

The effects it produces on sheep and how and where the injury is in- 
flicted may now be stated. 

Bracy Clark, an English veterinarian, describes the effect of theattack 


28 


of the fly in Transactions Linnean Society, 1797, vol. ITI, p. 315, as 
follows : 

Early symptoms.—The moment the fly touches this part (the nose) of the sheep, 
they shake their heads and strike the ground violently with their fore-feet. At the 
same time holding their noses close to the earth they run away, looking about them 
on every side, to see if the fly pursues; they also smell to the grass as they go, lest 
one should be lying in wait for them. If they observe one they gallop back, or take 
some other direction. As they can not, like the horses, take refuge in the water, they 
have recourse to arut, dry dusty road or gravel pits where they crowd together during 
the heat of the day with their noses held close to the ground, which renders it diffi- 
cult for the fly conveniently to get at the nostril. 


This description of the action of the sheep when attacked by the fly 
is correct in all but one or two minor points. The sheep’s actions when 
running indicate that they are taking every means to shake off and 
dodge a single rather than a number of pursuers. If this quotation 
had also described the sheep huddled under buildings, along fences, 
under rock ledges and shade trees, holding their noses close under their 
fellows, it would have completed a picture familiar to every farmer or 
flock-master. 

The fly only works during the heat of the day, while early in the 
morning and late in the evening the sheep seem to enjoy feeding in 
freedom from its annoyance. 

Pathology.—The young larva deposited in the nostril of the sheep im- 
mediately begins its migrations upward into the dark passages of the 
nose. It progresses by means of its hooks and spines. By firmly fix- 
ing the hooks into the mucous membrane it is enabled to draw up the 
rear part of its body after it, and by pushing upon the spines of the 
abdomen it holds itself in place while it thrusts out its head for a new 
hold. The only appearance of limbs that the larva has is the two rows 
of prominences along each side of the abdomen, as shown in Fig 13. In 
this method of progression lies one cause of irritation to the sheep, viz., 
the hooks sink into the mucous membrane and not only irritate it, but 
cause minute points of hemorrhage which are afterwards indicated by 
very minute black dots scattered over the surface of the nares or in- 
ternal nose. Whoever has felt the tickling and itching of a fly at the 
entrance to, or a foreign body in the nose, can imagine some of the sen- 
sations which induce the sheep to make such attempts to escape its foes. 

As the larva grows in size it finds its way farther into the recesses of 
the nose, and by following the grooved passage (see Plate III, Figs. 1 and 
2) penetrates into the furthest chambers. Fig. 1, », n, shows the young 
larvee wandering over the turbinated bones and in the main passage. 
One of these larve, advanced in size, is shown at 7 in Figs. 1 and 2 fol- 
lowing the direction of the channel marked by the straw 0, 0, which 
emerges into the frontal sinus of the head, k. The larve may also wan- 
der among the windings of the superior turbinated bones g, and finally 
growing to such a size that they can not escape, become entrapped 
there. The same may happen when they wander through the small ori- 


29 


fice, near but below that leading into the frontal sinus, which leads into 

, thesuperior maxillary sinus. (See Plate II, a, b.) A bit of straw has been 
inserted into theorifice to show the place of opening. From these places 
the larvee never emerge, but after maturing undergo calcareous degen- 
eration. Those that arrive in the frontal sinuses seem to thrive, and at 
the proper time are able to retreat through the orifice they first trav- 
ersed and are finally sneezed to the ground. This history and the fig- 
ures illustrating it, which have been drawn from nature, should satisfy 
sheepmen who have thought that because the grubs were in the head 
they must be in the brain. A glance at Plate ILI, with its three larvee 
in the sinus (there were originally seven in the head which the artist 
figured), will show that there is a bony partition, a, a, a, between the 
brain and the larvie. This is also the case in regard to those small larve 
which wander among the intricate windings of the upper turbinated 
bone, g. The larvie of the Gstrus, or the grubs, never do and never can 
penetrate into the brain. 

If one may judge from the black dots indicating a previous hemor. 
rhage scattered over the mucous membrane, the irritation set up by the 
wandering embryos is very considerable. In the sinuses of heads which 
contain older embryos other changes are to be noticed. They are filled 
with catarrhal matter which has been produced by the irritation of the 
larvee, and the mucous membrane is greatly thickened. These changes 
may also be observed over the turbinated bones, g, the greatest changes 
occurring in the superior, the one next the brain. The membrane 
which covers the latter is the one in which the nerves of the sense of 
smell are distributed, and a thickening of the membrane must greatly 
interfere with this sense. This is no small matter, for it is mainly by 
this sense that the sheep separates its food from other herbage. 

In addition to the catarrhal product and thickening of the membrane, 
it has been noticed that the membrane near the base of the turbinated 
bone—near m—is sometimes very dark colored. At this point the 
bone is exceedingly thin and pierced by a number of holes through 
which the olfactory nerves, or nerves of the sense of smell, pass. It is 
not unusual to find the membranes of the brain in the immediate vicin- 
ity blackened by minute dots, indicating a previous inflammation at 
this point. This affection of the membranes is probably caused by an 
extension of the inflammatory process from the nasal cavity. 

When the larve become entrapped in the maxillary sinus they ex- 
cite the same catarrhal secretions and thickening of the membranes as 
elsewhere, which finally fill the cavity, the outlet of which is at the top. 
All this irritation is due to the insertion of the claws and scratchings 
of the abdominal spines. The iarvee live on the material in which they 
move. They seem to obtain plenty of air even in the most crowded 
recesses. They continually cover and uncover the breathing pores 
(Plate I, Fig. 10a), and in so doing keep them cleaned of all foreign 


30 


material. Bracy Clark says that they make an audible snap in doing 
this, but the writer has not heard it. 

Late symptoms.—The chief symptom of the disease caused by these 
larve is the catarrhal discharge on the affected side of the nose, which 
gives rise to one of the popular names of the disease, ‘snot-nose.” 
Even this symptom may be absent when but few larvze are present. 

Neumann (Traité des Maladies Parasitaires, 1888, p. 501) accurately - 
describes the symptoms of affected sheep as follows: . 


Three or four lary ot (@strus are frequently found in the frontal sinuses of sheep 
which, during life, had never manifested any symptom. Itis only when these larve 
are numerous, and when they are quite well advanced in their development at the 
commencement of spring-time, that they occasion morbid troubles. The latter begin 
by a discharge, often unilateral, which is at first clear and serous, then thick and 
mucous. Frequently there is sneezing and snorting, accompanied by the expulsion 
of mucus and sometimes of (strus larvee. Later the animals turn the head back- 
ward, often shake it, rub the nose against the ground or some other object within 
reach, or with their front feet. As the malady gradually advances the sheep go with 
lowered head, lifting the feet high as if they were walking in water. Sometimes 
they quickly raise the head, carrying the nose to the wind, and then bend it back- 
ward convulsively. From time to time they stagger and are seized with vertigo, but 
do not turn in a circle. In severer cases there is difficulty of breathing, the first res- 
piratory passages being obstructed by the larve or the inflammation of the mucous 
membrane. The eyes are red and watery. The disease may be still further compli- 
cated. The sick lose appetite and rapidly grow poor; they grate their teeth; a 
frothy saliva runs from the mouth; their eyes roll in the sockets; convulsions arise 
and finally death ensues, sometimes within six or eight days after the appearance of 
the first symptoms. 

But the disease is rarely so fatal; it lasts longer, and the larvee having been suc- 
cessfully cast out, the symptoms generally become more favorable and by degrees 
completely disappear. 

This affection has sometimes been mistaken for ‘‘gid,”’ or ‘‘turn-sick,” due to Ca- 
nurus cerebralis, whence the name ‘ false gid,” or vertigo of strus, which has been 
given to it. Confusion will be avoided by recalling that turning in a circle does not 
take place in the present disease. The latter is nearly always accompanied by nasal 
discharge and snortings, which do not appear in true “ gid,” and which, besides, 
show themselves only in young subjects. 


Occurrence.—The larve of Gstrus ovis may be found in the nasal 
cavities throughout the year, and in nearly all stages of growth. This 
is more especially true of the southern portions of the United States, 
where the winters are mild and short. During the last winter and 
spring, in January and March, larve were collected of allsizes. Those 
represented by natural-sized figures (Plate I, Fig. 7), were collected in 
January at an abattoir in Baltimore, Md. Those figured in Plate IIT 
were collected in May. From the older of these grubs a pair of flies 
were hatched. The presence of very young larve during the past 
winter is very interesting, and indicates the presence of flies at an un- 
expected season. The usual time for the appearance of the fly is said 
to be during the months of June and July, and the usual period of 
pupation about two months. Two of my experiments showed that the 
time might be three weeks or four weeks exactly. The larve is said 


31 


to dwell in the nostrils about ten months. This statement has not yet 
been verified. In very young lambs only young larve can be found, 
while in yearlings the larve may be nearly adult, depending on the 
exact age of the iamb and the time it was infected. In yearlings the 
frontal sinuses are small and the grubs easily escape detection. It is 
in two-year-olds and older sheep that one finds the greatest infection. 
In ewes the sinuses are sufficiently roomy to Lold four or five larvie 
without crowding, but wethers, which have small horns, or bucks which 
have very large frontal sinuses, can harbor many more. Rarely have 
more than six or seven been found. Cases have been reported in other 
countries where far larger numbers, as many as ten to fifteen, were 
found. The largest recorded number seems to be from sixty to eighty. 
The relatively small number discovered, and the comparatively large 
size of the young when deposited, indicate that each female lays but 
few young. It is very unusual to find more than two or three larve of 
the same size, especially if they be mature or nearly so. The young 
larve are sometimes more numerous, six or seven of nearly equal size 
being found together. The presence of all sizes of larvz in the eavi- 
ties is a piain contradiction to the statements made that the fly appears 
only in June and July, for, no matter whether it takes ten months for 
the larve to grow or not, young and middle sized and mature larve 
found in the winter time could not all have been laid within the two 
months indicated. 

The more correct statement is that the fly may appear at any time 
when the temperature is not too low, but that they are more abundant 
in early and midsummer. 

Preventive treatment.—Most authorities on this subject recommend 
preventive measures, but practical application of the means and reme- 
dies proposed is necessary to demonstrate their utility. A change of 
pasturage or an avoidance of brush-fields does not seem to be advisa- 
ble unless the sheep are turned into longer grass, for the flies are able: to 
follow the sheep wherever they may go. 

A practical means of prevention consists in smearing the noses with 
a mixture of equal parts of tar and grease, or of tar and fish-oil, or of 
tar and whale-oil. The better way is to apply the preparation directly 
by abrush. Some recommend smearing the salt and grain troughs with 
the mixture, expecting the sheep while feeding to get more or less on 
the nose. This method is not thorough enough. Fish or whale oil 
alone is also recommended. Powers (American Merino, 1887, p. 300) ad- 
vises the following ointment for this purpose: Beeswax, 1 pound; lin- 
seed-oil, 1 pint; carbolic acid, 4 ounces. Melt the wax and oil together, 
adding 2 ounces of common rosin to give body, then, as it is cooling, stir 
in the carbolic acid. This should be rubbed over the face and nose once 
in two or three days during July and August. He also recommends an 
apparatus which may well be used by owners of first-class breeding 
stock, and possibly others who own but few sheep; “ A canvas face- 


32 


cover smeared with this mixture (the above), or with one of asafcetida 
and tallow, may be hung in such fashion as not to interfere with the 
sight or with grazing and yet protect the lamb against the fly.” 

Whatever the preparation used it should be periodically repeated 
throughout the season during which the fly is known to trouble the 
Sheep, as the nosing of the sheep in the grass, the accumulated dirt, and 
the rain all tend to make the preparation weaker and consequently less 
effective. 

Old authorities recommend plowing furrows in the pastures, but these 
will be beneficial only while the ground is dry and mellow. Removal 
of the grub immediately after if has been deposited is impractical. | All 
grubs seen on the ground should be crushed. Heads of slaughtered 
sheep should be cared for so that mature grubs can not escape to the 
ground. Sheep yards should be periodically cleaned and sprinkled 
with lime. 

Medicinal treatment.—This seems to be hopeless. A study of the life 
history of this parasite, which appears in the south at nearly all 
seasons of the year, and of the anatomy of the recesses into which the 
larva wanders, will convince one of the difficulties to be met with in 
treatment. In the first place, even if a suitable remedy were found, 
the sheep-owner would be compelled to resort to treatment as often as 
he found his sheep troubled, and would have to treat each separately. 
This arises from the fact that irritating fumigations or sneezing pow- 
ders, which pass into the lower part of the nose, would not affect the 
larvie in the sinuses no matter how violent thesneezing which they ex- 
cite. Injections of irritating substances would also fail, excepting pos- 
sibly in the hands of an expert, who, witha syringeand peculiarly bent 
nozzle, could perhaps learn to inject into the nasal sinuses. Even in 
that case failure would result in a certain proportion of cases, and the 
maxillary sinuses could not be injected, nor would the larve in the re- 
cesses of the turbinated bones be reached. In addition to all this, 
most remedies which would kill the larve would injure the delicate 
mucous membranes. For the flockmaster who may wish to try fumi- 
gation or nasal injections, the following recipe for fumigation as given 
by Blacklock is reproduced : 

One person holds the head in a convenient position in front of the operator. The 
latter, having half-filled a pipe with tobacco and kindled it in the usual manner, 
places one or two folds of a handkerchief over the opening of the bowl, then passes 
the stem a good way up the nostril, applies his mouth to the covered bowl, and 
blows vigorously through the handkerchief. When this has continued for a few sec- 
onds the pipe is withdrawn, and the operation repeated on the other nostril. 

Powers (0. ¢. p. 300) advises the following nasal injection, which should 
succeed if any will: 

It is best to procure at the drug store an elastic bulb syringe, price about $1, with a 
small nozzle 6 inches long. Mix turpentine and linseed-oil in equal parts. Accustom 


yourself to the action of the syringe so that you can gauge it accurately. Let the 
affected sheep be held before you in a natural position, and carefully probe the nos- 


trils with the nozzle until you find its bearing and depth (the nozzle will pass up a 
surprising distance—six inches in grown sheep). Then charge the syringe, intro- 
duce it to the extremity of the nasal cavity, and with a quick pressure inject about 
a teaspoonful of the mixture. Withdraw at once and let the sheep recover some- 
what from the effects of the shot, then treat the other nostril in the same way. * * * 
Keep the mixture well shaken. 


If the nozzle has a properly curved tip the injected mass will be more 
likely to reach the larvee. <A trial on the head of a recently dead or 
slaughtered sheep would give the operator more knowledge of the re- 
quirements to be met than any description. Olive oil is preferable to 
linseed. 

Surgical treatment.—There remains but one other method of remov- 
ing the parasites, and that is mainly surgical. If the disease is appar- 
ent on but one side (it may be on both), an opening is made into the 
froutal sinus (see Plate II), with a special instrument called a trephine. 
The opening is made on the dotted lines.which connect the middle of 
the eyebrows, and a little nearer the middle line of the head than the 

eye. The operation is a tedious one, requires some skill, and if advisa- 
ble to undertake with a number of sheep, should only be trusted to a 
competent veterinarian. Moreover, the ultimate results are not such 
that the operation could be advised in the majority of cases. Yet, as it 
is the only means that offers any hope for the worst affected, Ziirn’s 
directions (Raillet, Maladies Parasitaires, p. 504) for operating are given: 
Cut off the wool which covers the forehead. Trace with colored chalk a transverse 
line uniting the middle of the two superciliary arches (the eyebrows) and divide it 
by another line passing at the middle of the forehead. The point of choice for tre- 
phining will be in each of the two upper angles thus obtained without engaging the 
lines which limit them. The operation is performed according tothe ordinary rules 
of surgery. From the opening made one often sees the larvie, which are extracted 
by forceps. To kill others benzine moderately diluted with water is injected. The 
flap of skin is then cleaned, applied to the opening, and sewed to the adjoining skin. 
The whole is then covered with a turpentine coated leather plaster. The patient is 


separated for a few days from other sheep. Sheep bear the operation with the same 
impunity as they do marking the ears or other little operations. 


Trephining may also be resorted to for the large cavities at the base 
of buck’s horns, or for the maxillary sinus. The latter is a far more 
difficult operation, and the vicinity of important nerves and blood-ves- 
sels demands that only a skilled veterinarian should undertake it. The 
operation is, after all, only temporary in its effects, for the next larve 
laid in the nose will crawl into the same sinuses and create the same 
disturbances as those removed. 

Neumann’s advice, with which he closes his chapter on this parasite, 
is, perhaps, the soundest to follow, except in the case of breeders of 
valuable sheep : 

At all times, if the number of animals affected is considerable, the malady should 


be left to follow its course, and those which present the gravest symptoms should be 
sent to the shambles. 


23038 A P—3 


Fig. 
Fig. 


Fig. 


Fig. 
Fig. 
Fig. 
Fig. 


Fig. 
Fig. 
Fig. 
Fig. 
Fig. 
Fig. 


Fig. 
Fig. 


34 


CESTRUS OVIS, Linn. 


PRAHA 


. Larva in the first stage. Dorsal view. 
. Larva in the first stage. Ventral view. 
. Head of larya in the first stage: a, hooks by which the parasite attacheg © 


itself to the mucous membrane. 


. Tail of larva in the first stage: a, the stigmata or breathing pores, 
. Hooks of well-developed larva. 
. Hooks of very young larva. 


Larve in various stages of growth; natural size: a, a, a, fully developed 
larve in the thirdstage; b, three-fourths developed; cand d, yet younger 
larvie, possibly in the second stage; e, the youngest found, and those from 
which figures from 1 to 4 were taken. 


. Cephalic end of full grown larva (Brauer). 

. Dorsal view of full grown larva (Brauer). 

. Caudal end of full grown larva (Brauer): a, stigmata or breathing pores, 

. Adult female fly with line indicating natural length (Brauer). 

. Front view of head of the above (Brauer). 

. Ventral view of full grown larva, showing the spines which enable the para- 


site to push itself along the smooth, soft mucous membrane. 


. Pupa case dissected to show the imago or young fly within (Raillet). 
. Eggs taken from fly (Raillet), 


PLATE I 


Haines, del. A.Hoen & Co Lith Baltimore 


a ESTRUS OVIS, 
. (The Gad Fly of Sheep.) 


(ESTRUS OVIS, Linn. 


PLATE II. 


Dissection of the head of a sheep to show the cavities into which the gad-fly grubs 
penetrate. The straws indicate the passages from the cavities into the inside of 
the nose: a, the superior maxillary sinus, in which there is imprisoned the calci- 
fied remains of a fully developed larva; b, the ridge made by the infra-orbital 
division of the fifth pair of nerves; c, the infra-orbital foramen; d, an opening 
into the nares; e, ¢, the frontal sinuses with young larvwin them. The dotted 
line f, f, indicates the levei at which trephining, if it is done, should be per- 
formed. Figure reduced to three-fourths of natural size, 


Il ALWTd 


BOW [EW DySnesoysy Oo’) -y uaoy’y 


‘WAUVT SOQULSD Ad CACVANI GVAH S.dHAHS AO SUSONIS 


——— —L——  —————— —- = ee 


“jap ‘sauapyy 


Ba 
Ps 
rotors 


\ a 
, 


PGs 


? 


5] 


4 
Be 


(te 


Fig. 1. 


38 


(EsTRUS OVIS, Linn. 


PLATE III. 


Section of head of sheep made a little to the right of mesial plane: a, a, 
a, a, a, section of bone surrounding }, the brain, and ¢, the nasial cavity ; 
d, the lower jaw bone; e, nostril; f, opening of tear duct; g, g, g, turbi- 
nated bones; h, the posterior opening of the nasal cavity, andnear the 
opening of Eustachian tube; ¢, placed on the turbinated bone over a grub 
in the groove leading to the frontal sinus; k, the frontal sinus; J, the nasal 
sinus; m, the thin perforated plate of bone called the cribriform plate; 7, 
n, n, larve of Gstrus ascending the nares and wandering about its surface ; 
i, one ascending to the sinus; k, opposite three, nearly mature larve in the 
sinus. Figure reduced to three-fourths of natural size. 

Outline drawing of the skull surrounding the frontal sinus after removal of 
part of the turbinated bone, lettered as in Fig. 1; 0, 0, straws passed 
through the channels connecting the nares with the sinuses, marking 
the path by which the larva reaches the sinus; p, cut ends of the removed 
bones. 


WI ALW Id 


‘WAUVI SNULSW Ad CHACVANI 


GVHH SdHGHS HO NOLLOYS TVISHW 


‘jap ‘soupy 


via 


. 


\ 


i 


THE. SHEEP-TICK OR LOUSE-FLY--PHTHIRIASIS. 


MELOPHAGUS OVINUS, Linn. 


Plate IV. 


One ot the best known of all the external parasites of sheep is the 
sheep-tick, Melophagus ovinus, Linn. This pest is a very common one in 
the Eastern States, and although it seldom causes any serious. damage 
either to the sheep or to the wool, it is at all times an annoyance, and 
occasionally causes decided losses to the flock-master. 

This tick, like a majority of the parasites of the domesticated animals, 
was introduced into this country from Europe. The name “ sheep-tick,” 
though not a misnomer, as every one knows what a sheep-tick is, is 
misleading. So much do they resemble the true ticks that they are 
often classified together. The most superficial study will, however, 
serve to show their differences. 

Description.—The sheep-tick is a wingless fly having but six legs, 
whereas the true ticks are more closely related to spiders, and have 
eight legs in their adult state. The adults are less than a quarter of 
an inch long, and have a short, flattened, bristly, leathery body. The 
head is slightly wider than the thorax, into which it is sunk. They 
have very short antennx, which are sunk in sockets in the face; the 
proboscis is tubular, and is protected externally by two flat, elongated 
bristly pieces, the labrum; its end is armed with teeth. The thorax 
or limb-bearing portion of their bodies is nearly square when looked at 
from above. It is composed of three pieces, the middle being the one 
seen on the back. The legs are very stout, covered with bristles, and 
each is provided with two strong, sharp claws. The last joint of each 
foot bears a pinniform or feather-like organ whose office is as vet un- 
determined, but is probably that of coiling around hair for better pre- 
hension. There are no wings. On either side may be seen two small, 
bristle-covered, round spots at points where the wings should be 
attached. At the posterior outer corners of the thorax are two little 
projections which remind one of balancers. ‘The abdomen, usually 
Jarger in females than in males, is flattened and bag-like, and is as 
large or larger than the rest of the body, especially after the louse- 
fly has eaten, when the red blood sucked from its host may be seen 
through its skin. Its skin is tough, unsegmented, semi-translucent, 
and permits the abdominal organs to show through. On each side 
there are seven stigmata or breathing pores. The anus is situated on 

39 


40 


the ventral side and just behind the genital orifice. The sexes resemble 
each other, but may be separated by their size and by the form of the 
external genital apparatus. 

In habit these parasites resemble lice living among the hairs of the 
fleece, whence the name, louse-fly. They seldom remain attached to the 
skin longer than a sufficient time to fill up with blood; this they suck up 
through the proboscis with which they perforate the skin. They try to 
evade capture by running into the wool, and when caught cling tena- 
ciously. 

Life history.—The family of flies to which this parasite belongs is 
truly wonderful, in that they bring forth their young as puparia. The 
puparia of Melophagus are laid. as flat, ovoid, chestnut brown, glistening 
seed-like eggs, which are nearly one-third as large as the abdomen of 
the parent, and contain an imperfectly developed larva within them. 
The egg cases or pupa are marked by two rows of seven dots each on 
one surface, a slight depression, indented by two dots in one end, and a 
slight elevation at the other. The two dots are at the anal end. A 
dissection of one of these, taken from a female, shows the pointed end 
to be connected with a membrane, and to be the end through which the 
larva obtains food. 

Some authorities say that each female produces but one or two of 
these puparia; others say that they can lay about eight or nine during 
their life-time. They lay one at atimein the wool. A portion of each 
puparium will be found to be covered with a dry, dark substance, which 
came from the parent when the puparium was laid, was sticky, and glued 
it to the surrounding hairs. This prevents the pupa, which becomes 
hard, dry, and glassy, falling from the wool. The insect emerge, 
with adult characters from the pups cases, through an opening in the 
end of the case made by a round lid splitting off, and wanders into the 
wool. Some of these eggs collected in the course of our investigations 
hatched within four weeks at ordinary temperatures. 

Occurrence.—These ticks, or their young, may be found on the sheep .- 
at all times of the year, but appear to be most numerous in spring. 
They are particularly noticeable at shearing time on the old sheep after 
they are deprived of their shelter. At this time those that can do so 
take refuge in the longer wool of the lambs, and prove veritable pests. 

‘The others perish either from being eaten by the sheep, carried away in 
the wool, or dropped to the ground. They frequently become attached 
to the clothing and persons of people with whom they come in contact, 
but they prove but a slight source of discomfort, as they are easily 
caught and killed. It is not at all probable that they can exist many 
days apart from the sheep, as they are unfitted by structure for any 
other habitat. Their food consists wholly of the blood which they suck 
from the sheep. They depend also on the sheep for warmth ; in warm 
Spring days they may be found crawling near the ends of the wool, 
while in the colder days they will always be found either engaged in 


Al 


feeding or resting at but little distance from the roots of the wool. A 
dozen or more of these ticks, which were moderately well fed when 
taken from the sheep were, with some wool, placed in a cotton-stoppered 
bottle and kept in a room with a temperature varying between 60° and 
80° Fah. They all died in less than four days. The leanest succumbed 
first, in about two days, while those that were better nourished grad- 
ually grew smaller and thinner, and lived little longer than the third 
day. Others placed in wool over the damp soil of a geranium in a . 
flower-pot died within four days. On the other hand, some young ones 

which were hatched out in a bottle were kept for nearly two weeks, or 

until their daily feeding was neglected. ‘To feed them they were placed 

on the back of my hand. By this means I could, with a lens, watch 

them bore into the skin and see the abdomen slowly enlarge as they 

drew in the blood. They had some difficulty in penetrating the thick 

skin, but usually succeeded by slipping their tube into a hair follicle, 

At first no itching or irritation was felt, except a slight twinge when 

the bills first penetrated the skin ; but little swellings camé on a day or 

two later which itched for over a week. The itching was tar more per- 

sistent than with mosquito bites. They must in this way cause lambs 

much discomfort. It was at first thought that a fluid could be seen 

running from the parasite to the hand through the bill, but no more was 

thought of it until the elevations began to rise and itech; then it ap- 

peared certain that the little pests had secreted a poisonous fluid. The 

oflice of this secreted fluid is probably to assist the flow of blood by 

keeping it from clotting. 

The above experiments show that the parasite spends its whole life 
on the sheep. 

Source of contagion.—The fact that this parasite passes its whole life on 
the sheep, and that it produces but few young, are very important con- 
siderations in efforts for exterminating the pest and preventing a new 
infection. They indicate that if all are killed the sheep will not again 
he infected except from other sheep. 

Disease.—The injury sustained by sheep from these parasites varies 
according to the number present. It arises from the itching and pain 
inflicted by them when obtaining their food. A few cause but little 
annoyance, and, were it not that these may become the source of future 
multitudes, would be searcely worth noticing. To lambs the annoy- 
ance is particularly aggravating, as their skin is tender and the number 
of parasites attacking them after shearingis unusually large. In older 
sheep the irritation is the more noticeable towards spring. At thistime 
the parasites are more numerous and the animals bite and scratch them- 
selves oftener. 

Medical treatment.—The well-known means of ridding the sheep of 
these pests are the tobacco or other mixtures used for scab-dips. The 
best time of the year to dip is at shearing time. Then the older sheep 
can easily be handled and cleansed. The dipping should not be delayed 


AZ 


long after, for each additional day is cne of torment to the lambs. The 
lambs also should be thoroughly dipped. One dip is said to be sufiicient 
to kill the old parasites. However,a few of the pup may remain in the 
fleece of the lambs. They should be thoroughly examined two or three 
weeks after, and if there are any present they should again be djpped. 
All the precautions taken in dipping sheep should be carefully ob- 
served. The shoru wool should be stored where the young ticks which 
may hatch from the pupa cases can not crawl back to the sheep. How- 
ever, they seem to have great difficulty in crawling, and may not be able 
to go far. An experiment in which some of the pup became wet with 
moisture from other ticks in the same bottle demonstrated that they 
would not hatch, and indicates that the sheep bath will very likely kill 
the inclosed larvee. 

In The American Agriculturist, October, 1889, page 490, Mr. Joseph 
Harris advises fall dipping for these pests. This is a good plan if the 
sheep have become infested with ticks after the spring dipping by some 
inadvertence of the master. He advises the use of tobacco, carbolic¢ 
acid, and kerosene emulsion dips. The carbolic acid dip is composed of 
a pound of soap and a pint of crude carbolic acid to each 50 gallons of 
water. Dissolve the soap in a gallon or more of boiling water, add the 
acid and stir thoroughly. Keep the mixture well thinned, and do not 
let it get into the mouths, nostrils, or eyes of the sheep. Hold each 
sheep in the bath not less than half a minute. 

The formula for kerosene emulsion is as follows: Churn fresh 
skimmed milk and kerosene together in the proportion of 1 gallon of 
milk to 2 gallons of kerosene, either in a churn or by using a force- 
pump until an emulsion is made. The method of using the force-pump 
is to set it in the vessel containing the mixture and turn the stream 
back into the same vessel. The emulsion will form quicker if boiling 
hot milk is used. For dipping use 1 gallon of the emulsion for each 10 
gallons of water required. Mr. Harris seems to think 20 gallons, with 
a reserve of 10 gallons, sufficient ; but he was evidently thinking of a 
very few sheep. He did not use this emulsion, but a variation made 
with soap, as follows : j 

Boil a gajlon of water, dissolving a pound of soap in it; add 2 gal- 
lons kerosene; churn the mixture until it emulsifies, or until all the oil 
is'“eut.” Use 1 gallon of emulsion to 8 of water. Mr. Harris ad- 
vises dipping twice with an interim of two weeks. 

Fifty gallons ot the dip will suffice for fifty sheep. Seventy would 
probably answer for one hundred; but much depends upon the amount 
of waste on account of the liquor being carried off by the fleece. The 
recipe is very easily modified for ranching purposes. 

The emulsion has already been advised for cattle lice in Bulletin No. 5, 
Iowa Agricultural Station, p. 184, May, 1889, and for cattle ticks in 
Insect Life, Vol. 11, No. 1, p. 20, U. S. Department of A griculture, 
July, 1889. Though the efficacy of this remedy against the various 


43 


kinds of insect parasites of domestic animals has yet to be tried in de- 
tail, its importance in this field has already been demonstrated. 

Preventive treatment.—The sheep should not be turned into the old 
pens or pastures until a week after the first dip, by which time it may 
reasonably be supposed that all parasites on the ground have died. To 
avoid the chance of any recently hatched parasites getting from the 
ground to sheep in places where the sheep rest, it is best to scrape out 
and cleanse the pens. Animals recently purchased should always be 
dipped before being added to the older flock. 

By following out a thorough plan of treatment, and by carefully 
guarding the sheep from re-infection, the flockmaster should be able te 
rid his flocks of this pest in a single season. 


44 


MELOPHAGUS OvINuS, Linn. 


PuaTE IV. 
Fig. 1. Female sheep-tick: 1a, larva case, each natural size. 
ig. 2. Male, dorsal view, x8: a, head; b, thorax; e, abdomen; d, limbs; e, oval 


bristle-covered disks, which camreeann to ay points of gihaclonaehge wings 
in other flies; f, rudimentary halteres or poisers. 

Fig. 3. Male, ventral view, x8: g, h, andi, the three segments of the thorax; k, the 

external erie 

Vig. 4. Female, dorsal view, <8. 

Fig. 5. Larva case, X8: a, cephalic end ; b, two rows each of seven shallow indent- 
ations, 

Fig. 6. Foot: a, the two claws between which hangs b, the pinniform prehensile * 
organ ; ¢, the tarsi, whose last joint d supports the prehensile organ; e, 
distal end of the tibia. 

Fig. 6a. Prehensile organ, x60: a, the segmented muscular portion included within 

the tarsus; b, the flexible grasping portion. 

Fig. 7. Front view of head: a, the compound eyes; b, the antenne sunk in enp- 
like cavities; ¢, the labrum which protects the sucking organ. 

Fig. 8. The sucking apparatus: a, the labrum; ; b, the orifice from which the tube 

protrudes; c, the sucking tube. 

Fig. 9. End of the sucking tube, x120: a, teeth by which the tube cuts its w way 
through the skin; b, rod upon which the teeth are set: ; ¢, tube which has 
lateral orifice in it. Other details not shown. 

Fig. 10. External genital apparatus of female: a, Spine-covered cap which fits over 
b, the genital orifice above; ¢, two clusters of spines which seem to be for 
clasping; d, the terminal of the seven pair of stigmata or breathing pores ; 
e, anus. 

Fig. 11, External genital apparatus of male: a, the two lateral of the three chit- 
inous styles which surround the projecting intromittent organ; b, two 
clusters of spines which seem to be claspers; ¢, stigmata. 

Fig. 12. Larva case, x6: a, case with the broken operculum inside ; b, cephalic end, 
showing line where the opereulum splits off and the remains of a cen- 
tral orifice through which nourishment was obtained by the embryo from 
the parent; ¢, candal end showing the two dots corresponding to the two 
terminal stigmata, 

Fig. 13. Larva ease with larva, x6: a, ventral yiew; 6, dorsal view. 


We 


Haines, del. 


MELOPHAGUS OVINUS, 
(The Louse-fly.) 


AAT I 


PLATE IV 


A.Hoen & Co, Lith. Baltimore 


46 


ter. The markings on the under side of the head and the form of the 
caudal end of male and female seem to differ from others, but these 
differences are unessential for the present description. The form that 
most nearly approaches it in general appearance is the Trichodectes 
pilosus, Giebel, from the horse, but the latter is a relatively larger spe- 
cies. The species is to be found on poorly nourished young sheep in 
places where the wool is scanty. A favorite place is between the legs 
and body, just under the shoulder. Coarse-wooled sheep are more 
afflicted with them. 

The life history of these pests is very simple. The adults lay their 
eggs on the wool fibers at their base, and a glutinous material sticks 
them there (Plate V, Fig. 6). The eggs hatch out in the wool, and the 
young louse emerges by pushing off the cap (Figs. 7and 3). The young 
then grow to be adult. It is most probable that sheep can only get the 
lice from other sheep, as another host of Trichodectes sphwrocephalus is 
yet unknown. The presence of these parasites may easily be learned 
by searching for them or their eggs. Sheep affected manifest their 
presence by scratching themselves with their hind feet or by rubbing 
against Stationary objects. 

Disease.—The injury wrought by this parasite is caused by its life- 
habits. The injury effected by species of Vrichodectes is not as de- 
cided as that caused by those of Haematopnus, the genus to which the 
true lice belong. The mouth parts of the latter are so arranged that it 
can live on the blood of its host, and in biting through the skin it 
causes an itching sensation and a wound. The Trichodectes, however, 
are not fitted for penetrating so deeply, and appear to go but little 
deeper than the epithelium. They can probably bite through to the 
young growing tissue, for animals which are severely afflicted with 
these pests have a roughened, scabby skin, which would not be the case 
if the parasite only lived on the hairs and epithelial débris. The pres- 
ence of these parasites on the skin not only gives discomfort to the sheep, 
but causes the skin to thicken, become rough and covered with little 
dry, black scabs, and the wool to become short, dry, gnarly and worth- 
less wherever the pests attack the skin, 


48 


TRICHODECTES SPH AZROCEPHALUS, N. 


PLATE V. 


In Plate V, figs. 1, 2, 3, 6, and 7, and in Plate VI, figs. 1. 2, 3, 5, 11, 12, 13, and 15 
are equally enlarged, and present relative differences in size and form. Other parts 
are also enlarged similarly for the sake of comparison. 


Fig. 


Fig. 


Ds 
Fig. 1 


i 


2. 


we 


Male, natural length indicated by line. 

Female, natural length indicated by line: a, head; b, antennx; e, face; 
d, cheeks; e, ¢, dorsal sutures; f,f,/,legs: g, prothorax; hk, metathorax; 
i, abdomen ; k, dark transverse bands; J, line of hairs on each segment; 
m,m, stigmata or breathing pores; (lig. 1), male genital orifice; 0, female 
genital orifice; p, female claspers, 

Young specimen just emerged from shell. 

Male antenna. 

Female antenna. 

Egg soon after being laid: a,cap with peculiar red-like structure; }, line at 
which the cap is to cleave off. 

Ege shell which has lost its embryo and cap: b, b, wool tibers. 

Anterior leg: a, coxa; 0b, trochanter; c, femur; d, tibia; e, tarsi and claws. 

Posterior leg. 

Head, ventral side: a, a, antenna; b, b, ventral continuation of dorsal sut- 
ure; c, ¢c, ventral suture; d,d,mandibles; e, waxille showing through 
the chitinous gular plate; -f, the labrum. 

Tail end of male, dorsal view: a, the last segment; b, the genital orifice ; 
c, chitinous, hook-like appendages of the genital apparatus. 

Tail end of female, ventral view: a, the last segment; 6, the genital and 
anal orifice ; ¢, the claspers. 


PLATE V 


11 
] Di Pec 


(Ga 
yh Dey 


SAAS fice, § 


TRICHODECTES SPH #ROCEPHALUS, A.Hoen & Co, Lith, Baltimore. 
(The Sheep Louse.) 


= 
=) 
& 
. 
- 
. 


GOAT LICE. 


TRICHODECTES LIMBATUS, Gervais. 
Plate VI, Figs. 1-8. 


Description.—Trichodectes limbatus, Gervais—the Angora louse—re- 
sembles 7. climax closely, but differs in specific details. All the brown 
markings on 7. limbatus are darker and wider; the head is slightly 
more indented in front; the dorsal suture (Plate VI, fig. 2 e, e,)is more 
pronounced; the head is wider in proportion to its length. The banded 
margin of the abdomen is wider. The greatest difference lies in the 
disproportion of size between the male and female of TZ. limbatus, and 
the character of the transverse bands of the abdomen of the male; the 
abdomen of the male being shorter is relatively wider in proportion to 
its length, and has a quadrangular appearance. The first band is nearly 
straight and one-third shorter than the three succeeding, which are of 
nearly equal length and convex anteriorly, concave posteriorly. The 
fourth and fifth segments bear a second narrow band near the posterior 
margin. The egg of this species is larger than that of ZT. sphwroceph- 
alus or T. climax. 

The marked differences shown between the bands of 7. climax and T. 
limbatus was a constant one in all males examined. This feature, in 
connection with the difference in size of the eggs. and the many minor 
differences of form and color, seem to be specific. The males of these 
species seem to offer the most tangible characters for separation. When- 
ever other species of this genus are described particular attention to 
the males should, on this account, be given. The females seem to ap- 
proach each other more closely. 

Occurrence and disease.—The goat louse is common, and causes more 
trouble to goats than the little red-headed louse does to sheep. When 
present it occurs among the coarse hair along the back and sides of the 
goat. It causes much discomfort and scabbiness of skin. If the ani- 
mals are severely infected they become poor and thin. The Angora 
goat louse caused, in the single flock in which it was seen, not only a 
severe scabby skin disease, but a loss of fleece. The whole back, sides, 
and head seemed to be completely covered with the parasites, young 
and old, and nits. 

Treatment.—The disease caused by these parasites is of that class 
which is preventible, and it is inexcusable if it be allowed to continue. 
The history in each ease is that of infection from other sheep, goats, or 
Angoras, as the case ay be. As the parasites spend their whole lives 
on these animals they may be killed on them and not be expected to 


23038 A p——4 49 


50 


come again except from other animals of the same kind. Yards, where 
any of these animals are kept, should be sprinkled with lime and the 
walls washed with diluted lye, or whitewashed before the animals which 
have been treated are returned. This will ensure safety from any par- 
asites Which may have fallen to the ground where the goats have lain. 
The treatment should be thorough. As these animals are small the 
best method is to immerse them in tobacco water, thus insuring the de- 
struction of every parasite and nit, even those on the nose, by immers- 
ing them while holding the nostrils. If the hair is long on the Angora 
they should by all means be sheared. If it is not desirable to dip them, 
the selected remedy may be sopped on the skin and wool and thoroughly 
rubbed in so as to wet the skin. 

Medicines may be applied in three forms: in powders, as pyrethrum 
or Persian insect powder, and tobacco dust; in ointments, as oil or lard, 
with some added ingredient, and in baths, as the tobacco or arsenical 
dips. Of these the first is the more objectionable and the least valuable. 
The second is better, but not entirely successful. The third is the one 
which should be used in the majority of cases, as it is the most certain. 

The following recipes are among tliose in use, and are recommended 
by various authorities : 

A decoction of stavesacre seeds, 5 ounces to 2 quarts of water, to be 
thoroughly rubbed in. (Neumann.) 

A decoction of stavesacre seeds, 1 ounce to 1 quart of water or vine- 
gar, or half water and half vinegar. (Finlay Dun.) 

In powders, tobacco, pyrethrum, stavesacre and sabadilla may be 
used, but the last two are not advisable. 

Benzine 1 part, soft soap 6 parts, water 20 parts, or petroleam (kero- 
sene) 1 part, sweet oil 10 parts. (Neumann.) 

Schlegs’ mixture is recommended in Germany for its efficacy and 
harmlessness when prudently used. Arsenious acid one-half ounce, 
potash one-half ounce, water 3 pints, vinegar 3 pints. (Ziirn.) 

The most efficacious remedies are the tobacco, or the tobacco and 
sulphur dips, advised for scab. For flocks of large numbers, nearly all 
other recipes are unavailable. 

Mercurial salves should not be used. 

Ziirn advises tobaeco 1 part, water 20 parts, or water 20 parts and 
vinegar 10 parts, to be made into a decoction, and vinegar added after 
cooling. The kerosene emulsion may also prove a valuable remedy. It 
should be applied as directed for exterminating sheep-ticks, or by means 
of a force-pump and spray-nozzle. 


TRICHODECTES CLIMAX, Nitzsch. 
Plate VI, Figs. 11-18. 


The common goat, Capra hircus, L., is quite commonly infested by a 
Species of louse which has been identified by the writer as Trichodectes 
climax, Nitzsch, and the Angora goat, Capra hircus, var. Angorensis, by 


5] 


one which seems to be Trichodectes limbatus, Gervais, or T. climax, var. 
major, Piaget. The name applied by Gervais is accepted, for the differ- 
ences between the two appear to be specific and not varietal. 

Description.—The characters of Trichodectes climax are: Head wider 
than long, quadrangular, presenting a wide but shallow indentation in 
front, at which the two antennal bands stop; antenne hairy, 4 little 
longer with the male than the female; the first joint is larger and 
shorter than the others; the second longer than the third ; the abdomen 
bears median spots, the width of which diminish as their length in- 
ereases. The last segment of the male carries two hairy ecashions. 
Head and thorax, reddish-brown ; abdomen, pale yellow ; spots, brown- 
maroon; bands, blackened. Length, female, 1.6™; male, 1.3™".  (Neu- 
manu.) 

The female of this species is broader and the male a little shorter than 
in the corresponding sexes of 7. spherocephalus. The dorsal sutures of 
the head are much darker and plainer; the edge of the head and ad- 
domen are margined by a pronounced dark band. The differences 
between the anterior and posterior feet are much more decided. The 
dark bands of the back of the abdomen of the male seem to offer the best 
characteristics, viz: They gradually increase in length to the fourth, 
when they begin to narrow. Beginning next the thorax the first band 
is narrow; the second, third, and fourth are wider; the succeeding are 
narrower ; posterior to the line of hairs on the second to the fifth seg- 
ments are extra narrow bands, which are about equal in width. The 
egg of this species is shorter and narrower. 


Fig. 


Fig. 


Fig. 3. 
Fig. 
Fig. 
Fig. 
Fig. 
Fig. 


3 
4. 
6. Antenna of female. 
de 

8. Posterior leg. 


52 4 


TRICHODECTES LIMBATUS, Gervais. 


PATE OValc 


. Male, natural length indicated by line. 
. Female, natural length indicated by line: a, head; b, antenne; ec, clypeus; 


d, cheeks; e, e, dorsal sutures; f, f, f, legs; g, prothorax; h, metathorax ; 
i, abdomen; k, k, dark transverse bands; J. 1, lines of hairs; m, m, breath- 
ing pores; n, male genital orifice; 0, female genital orifice; p, female 
claspers; g, male genital hooks. 

Head, ventral view: a, antennze; b, mandibles. 

Posterior end of female, ventral view: a, genital and anal orifice; b, claspers, 

Egg: a, the cap; b, the line where it splits off. 


Anterior leg: a, coxa; b, trochanter ; c, femur; d, tibia; e, tarsi and claws. 


Trichodectes climax, N. 


Figs. 11 to 18. Numbered and lettered for the same parts as Fig. 1-8. 


PLATE VI 


Haines, del. : Mersendc Goliath HEalstnerces 


TRICHODECTES LIMBATUS, TRICHODECTES CLIMAX, 
(The Angora Goat Louse.) (The Common Goat Louse.) 


THE LICH OR SCAB INSEGIS—ACARLASIS—ITCH—SEAB: 
SARCOPTES, Latr.; PSOROPTES, P. Gerv.; CHORIOPTES, P. Gerv. 


Of all the diseases caused by external parasites those due to the scab- 
making insects are of the first importance. The losses due to them are 
very heavy, and are exceeded by those of no other external parasite, 
and equal those of the most destructive of internal parasites. Owing 
to the means used in preventing flocks from becoming infected, and to 
the extermination of the pests by the proper use of efficacious remedies, 
these losses are annually becoming reduced. It is to be hoped that in 
the near future, through the exercise of proper sanitary laws, this most 
tractable of all the parasitic diseases may be completely exterminated 
in our country. 

Scab is a disease due to the presence of minute insects which lead a 

. parasitic life on the skin of their hosts. It is caused by: the inflamma- 
tion they excite in penetrating the skin, that they may procure food for 
themselves and young, and suitable conditions under which the eggs 
may be deposited and hatched and the young matured. The disease is 
thought by some to be aggravated by a poisonous fluid secreted by the 
insects, which adds to the intense itching. 

The malady proceeds step by step with the growth, propagation and 
decay of the innumerable insects which result from the acquisition of a 
single fertile female or a few pairs of individuals, and the spread of the 
disease, therefore, coincides with an increase in the numbers of the par- 
asites, while the limitation of the disease follows their extermination. 

There are at least three different species of scab-forming insects, 
parasitic on sheep, and each species is not only specifically different 
from the other, but the disease caused by each is different. This is 
due to the variation in the anatomical structure and habits of life in the 
several species of these pests, which causes them to attack the skin in 
different places and by different methods, and hence gives rise to the 
various symptoms common to each disease. 

These insects are known as Acari, and the diseases they cause as 
acariasis. The various species parasitic on sheep are Sarcoptes scabiei, 
de Geer, var. ovis; Psoroptes communis, Fiirst, var. ovis; Chorioptes 
communis, Verheyen, var. ovis. Of these the Sarcoptes causes scab of 
the head; Psoroptes causes common scab, and the Chorioptes foot scab. 

The life history of these parasites is in general very similar. They 
attack the external skin of the animals in which they live by biting it. 
Soon after scabs are formed. Under these scabs the insects lay their 


03 


54 


ovoid eggs. After two or three days these eggs hatch, and in fifteen days 
the progeny become adult. Each adult female is estimated to lay about 
fifteen eggs, two-thirds of which produce females. When hatched the 
young invade new territory and lead the life of their parents. The ex- 
tension of the invading hosts is due to their migration and rapid propa- 
gation. The disease usually spreads as a constantly growing patch. 
The infected sheep sometimes scatter the scabs by scratching ; these, 
in turn, become new centers of infection. The multiplication of the 
invading pests ceases only at the death of the host, or when they 
are killed by the use of proper remedies. To illustrate the rapid 
increase of the Sarcoptes, Gerlach, a scientist, computed that in three 
months a single female would produce 1,500,000 progeny. He esti- 
mated that each adult female laid fifteen eggs, of which ten were 
females, and that the eggs became adults in fifteen days. The result is 
shown in tabular form as follows: 


Females. Males. 
First generation after 15 days produces.. -. 10 5 
Second ‘ Goesaile OC Bt fess 100 50 
Third = ¢ 6 SA “ eae 1, 000 500 
Hourch | GS = (0) 6 oC ee LOROO0 5, 000 
Fifth « “oR Ot és 584 1008000 50, 000 
Sixth s¢ COE OO aS as ...-1, 000, 000 500, 000 


This table presents a very moderate estimate of the rate of propaga- 
tion. A microscopic examination of minute particles of scab shows 
them to be teeming with young and old parasites, and would seem to 
confirm the estimate given. As but few of the parasites may be trans- 
ferred to a healthy animal, it is evident that up to the second month 
but little advance in the disease will be noticed, but after that time the 
tentold increase every two weeks produces an enormous number of the 
parasites and causes the disease to advance with wonderful rapidity. 


THE HEAD SCAB. 


SARCOPTES SCABIEI, de Geer, var. OVIS. 


Description.—The insects which cause this variety of scab are almost 
invisible to the unaided eye, and are among the smallest of the scab- 
making insects. They are known as Sarcoptes scabiei, de Geer, var. 
ovis. They may be recognized by their rounded or somewhat oval 
bodies, their small heads, which are furnished with a biting apparatus, 
and by the adult having four pairs of legs. The young have but three 
pairs of legs. Other anatomical characters, which are different in ditter- 
ent species, are present, but for the flockmaster these are unessen- 
tial, as the species can be separated by biological characters which are 
plainer and easily understood. 

Disease.-—Head scab begins on the upper lip, and about the nostrils ; 
more rarely it may show itself for the first time about the eyelids and 


5D 


ears. In these places there is less hair and grease, affording the pests 
better opportunities of getting at the skin. From these starting-points 
the scabs spread over the forehead, cheeks, eyelids, and occasionally 
over the space under the jaw. In badly infected sheep the disease may 
sometimes extend to the fore limbs, under the belly, around the joints, 
and especially between the foids of the knees, hocks, and pasterns. 
Sheep with coarse dry wool are more likely to suffer this extended 
invasion than those, with fine, oily, and soft wool. Long wool seems 
to offer a barrier to its progress, for the invasion of parts covered by 
short wool is much more rapid. The demarkation between the invaded 
parts of the head and the healthy wool-bearing portions is quite abrupt. 
In coarse-wooled breeds the disease may rarely cover the entire body. 
The first indication of the disease is shown by the sheep in rubbing or 
scratching its head. The intensity of the itching is manifested by the 
violence of the sheep’s action. The first that can be seen on an infected 
spot is little elevations with soft centers. These elevations break of 
themselves, or through the rubbing they receive, and from them runs 
a watery fluid that in drying forms little hard bunches whieh stick to 
the skin and adjacent hairs. These little elevations are made by the 
parasites, which sink themselves into the skin. Here the parasites find 
suitable food, grow and produce their young. These migrate and pene- 
trate into the skin as did their parents. Thus the disease spreads 
slowly as the parasites increase. Finally, as they become more numer- 
ous, they cover the invaded skin with a thin layer of scabs. As the 
disease advances the little scabs not only run together, forming one 
mass, but they become thicker, whitened, and hard. Later they run 
together over the nostrils, lips, face, cheeks, forehead, eyes and ears, 
and form a dry, hard, thick, seabby mass. By repeated rubbings this 
scab breaks up, and the skin tears, cracks, and bleeds. Later the 
wounds heal and sears are formed. When the scabs cover the eyelids 
the latter close up and the animal becomes practically blind, being un- 
able to find its way or to see food. The insects are to be found in the 
moist layer underlying the scabs. 
Source of contagion.—The insects which cause the disease have been 
derived from other sheep with which the recently infected flock may 
have come in contact, or which may have left a few parasites on some 
brush or stick, or in some trough with which the uninfected flock came 
in contact. The methods of infection are various, but he who under- 
stands that these parasites always come from some where else, and 
always from some infected flock, will soon learn what to do to prevent 
his sheep from becoming infected. The variety of Sarcoptes parasitic 
on sheep is similar to the variety living on goats, and it has been ex- 
perimentally proven that each variety may be transferred and will live 
on either animal. Some of the varieties living on other animals may 
be transferred to sheep, but they do not thrive. It is not at all prob- 
able, therefore, that sheep are infected from other animals than sheep. 


56 


Diagnosis—Head seab can not well be confounded with any other 
variety of scab. The seat of the disease and the presence of the para- 
site, which is scarcely visible to the unaided eye, are sufficient to defi- 
nitely diagnose the malady. 

Prognosis.—This variety of scab is one of the most amenable to treat- 
ment. Being mostly on the head it is easy to reach with remedies. If 
treated it will prove of little loss to the flock-master, whileif allowed to 
take its course it will continue for a long period, gradually growing 
worse and rendering the patient more and more unsightly and ill-fa- 
vored. It can cause severe inflammation of the eyes and ears. It ean 
hinder the fattening of the animal and cause extensive alterations of 
the tissues of the skin. By affecting the health of the sheep, it will not 
only decrease its weight but materially lessen the amount of wool pro- 
duced. 

Medical treatment.—The worst feature of treating the disease is, that 
treatment for a complete eradication seems to be extreme aud out of 
proportion to the end to be attained. Curative treatment always yields 
good results when the application is rational. In the early stages of 
the disease, when the scabs are just formed, simple applications of scab 
dips or ointment are all that are needed; in cases of longer standing it 
will be found necessary to first soften and loosen the scabs with some 
kind of grease or oil, and then to remove them with some alkaline solution 
orsoap. The thin oils (sweet oil) that penetrate are the best. The wool 
adjacent to the scabs should be cut away so as to allow the remedies to 
get at the newly affected portions. 


COMMON SCAB. 
PSOROPTES COMMUNIS, Fiirst., var. OVIS. 
Plates VII and VIII. 


Common seab is caused by an insect known as the scab-mite or itech 
insect— Psoroptes communis, Fiirst., var. ovis. This insect is much larger 
than the Sarcuptes, which causes head scab, being visible to the unaided 
eye. x 

Disease.—Of all the diseases of sheep in this country, scab is the most 
feared by the tlockmaster. So insidious is its attack, so rapid its 
course, so destructive its effects, and so difficult is it to exterminate 
that it has justly earned the distinction of being more injurious than 
any other disease caused by external parasites. Scab alone, of the par- 
asitic diseases, has become the subject of legislation in most countries, 
and yet, if proper precautions were taken and a rational treatment fol- 
lowed, this disease could soon be completely eradicated. 

Karly symtoms.—Attention to the disease is first attracted by the in- 
fected sheep seratching, biting, and rubbing themselves. The coats 
of the animals look rough, taggy, and felted. The itching is always 


He 


most violent when the sheep have been heated by driving or warming 
in a stable. 

Pathology.—By separating the wool and examining a recently infected 
spot, there can be seen some minute elevations, which differ from the 
surrounding skin in being slightly whiter or yellower, and which have 
been produced by the bites of the pests. The insects themselves can 
be found among the hairs at but little distance from the bites. As time 
passes and the insects multiply in numbers these elevations become 
more and more numerous, and closer and closer together, until they 
finally unite over a considerable extent. From the summit of each eleva- 
tion or papule, a watery, serous fluid exudes and accumulates, which 
transforms them into vesicles and pustules, and which in drying cover 
them over with a thin crust. Ina few days the whole surface is cov- 
ered with a yellowish, greasy, scaly layer, under which the parasites 
are hidden. As the disease proceeds this layer gradually increases in 
thickness by an increase of the serous exudate, and in circumference 
by the extension of inflammation produced by the ever-multiplying par- 
asites which live beneath it, forming scaly crusts. These crusts, in be- 
ing torn out, mainly by the rubbing with which the sheep endeavors to 
allay its intense itching, carry with them the tags of the wool, the loss 
of which is an early symptom of the disease. At a later period the 
‘crusts are replaced by another set of thicker, firmer, adherent scabs, 
which are still further enlarged by the outward migration of the para- 
sites. As they abandon the center of the scabs these are again replaced 
by a peeling off of the external layers of the skin, which gradually 
heals, while the disease slowly progresses at the outside. The complete 
cure is very slow, and the skin remains thick and folded for a long 
time. In sheared sheep the skin becomes covered by a thick, dry 
crust, like parchment, while beneath if remains much swollen. 

Late symptoms and diagnosis.—The fleece of scabby sheep presents a 
characteristic rough look. In places the wool is’ stuck together in 
masses; in others it fails, while in others, which are apparently sound, 
it can be easily plucked off. The rubbing and scratching indulged in 
by the sheep not only tend to tear away the wool but inerease the 
irritation of the skin, which may become intensely inflamed and swollen 
and finally end in a superficial death of the part. Unlike Sarcoptes, 
the Psoroptes seeks the longest, thickest wool. It begins its attack along 
the back and extends to the neck, flanks, and rump. The Psoroptes 
are rarely found in the region of the chest and abdomen. They are 
collected in masses on circumscribed surfaces. The scabs they produce 
constantly increase at their edges, and their number depends on the 
number of places invaded. Owing to the closeness in which sheep con- 
gregate and to their violent scratching the parasites become very gen- 
erally scattered and finally the scabs may run together. 

While few of the parasites are present in the older diseased parts, at 
the edges of the scabs they can be found in swarms. They look like 


58 


little white points .with a brownish extremity. If picked up by the 
point of a knife or a sharp stick and placed on the hand they will be 
seen to move. The six-legged young, the ecight-legged adults, the 
sexes, couples joined together, and the eggs of this interesting insect 
can easily be identified by the aid of a low-power magnifying glass. 

Prognosis.—The disease is favored in its advance by the seasons in 
which the wool grows longest, and in which the sheep are brought into 
closer contact in sheds. Autumn and winter are the most favorable 
for its spread and rapid advancement. In summer, and especially after 
Shearing in spring, the disease makes little, if any, headway until the 
wool has grown to a considerable length. Age, temperament, state of 
health, energy, and race of the animals, the length, fineness and abun- 
dance of fleece, and the hygienic surroundings have much influence on 
the advance, progress, and termination of the disease. The young, the 
weak, the closely in-bred, the long coarse-wooled sheep, and those sub- 
jected to bad climate, to unhealthy localities, to poorly constructed, illy- 
ventilated sheds, are all more subject to the rapid advances of the 
disease. On the other hand, healthy, well-fed, well-loused sheep may 
withstand the ravages of the disease for months. 

When left to itself scab causes severe disturbances of the functions 
of the skin, and on account of the intense itching brings on fatigue, 
through loss of rest and sleep. Marasmus and cachexia preceding, 
death may come to weak, ill-nourished subjects in two or three months. 

The mortality due to scab varies much, depending on the season, gen- 
eral health of the flock, food, shelter, and a variety of other factors. It is 
most disastrous in autumn and winter among sheep poorly fed and housed, 
and of weak constitutions. Many other diseases may intervene and carry 
off the weakened animals. The death-rate is not the only occasion of 
loss, for whether the shepherd keeps his flocks for mutton or wool he 
will find a loss in either, depending much on the severity of the dis- 
ease. Ewes weakened by the disease will remaininfertile, abort or pro- 
duce but weak and feeble lambs, which will either die or searcely be 
worth the rearing. To this loss must be added the decreased value of 
the wool obtained from the first shearing after a recovery from the at- 

tack, due to the mixing of the ends of the old wool with those of the 
new, known as the double-ended w ool. This mixture lessens the value 
for manufacturing purposes. 

Source of contagion.—Remembering that common seab is caused by 
insects which the infested flocks are continually spreading broadcast 
by dropping tags of wool by the wayside, by leaving them attached to 
brush, by rubbing posts and fences, it is easy to realize that there are 
many methods of transmitting the malady. Experiments with these 
insects have shown that they can live at a moderate temperature on a 
piece of scab from ten to twenty days; that they may live after being 
subjected to intense cold; that they die more rapidly when they are in 
contact with animal matter at freezing temperature, and that they die 


59 
Soon if they remain exposed to alternating high and low temperatures. 
These experiments show that the Psoroptes can live about the sheep 
sheds, yards, corrals and fences during twelve or fifteen days, at least, 
after they have separated from the sheep. 

Although this species of parasite is but a variety of the Psoroptes 
communis, of which the Psoroptes parasitic on horses is another variety, 
the latter has not yet been made to grow on sheep experimentally. It 
is not probable that either of the varieties parasitic on cattle or rabbits 
would thrive on sheep. That is to say, so far as is now known, sheep are 
infected with common scab from other sheep, and can not acquire it 
from other animals. On the other hand, the ovine variety of Psoroptes 
has not yet been found to growon other species of our domestic animals, 

Differential diagnosis.—Psoroptic, or common scab, is different from 
Sarcoptic or head scab, in that the former chooses to live where the fleece 
is longest, and the latter where there is little or none at all—the one on 
the back and sides, the other on the head and occasionally on the nether 
parts; the one is almost invisible to the naked eye, and the other is 
plainly seen, though small. The itch due to other parasites, such as 
sheep ticks and sheep-lice, can be easily separated, because they are 
large and can be found in the wool. Sheep are sometimes subject to 
an inflammation of the sebaceous glands. In this, however, there will 
be no parasites of any kind found. 

Prognosis.—Scab, as has been said before, is one of the most dreaded 
diseases of sheep. For the flockmaster who has but few sheep, say 
fifty or a hundred, the task of treatment and eradication of the scab 
from the flock is no easy affair; but for him who owns from five to 
twenty thousand the difficulties to be met are enormously increased. 
Though the disease may be easily tréated as far as a single sheep is con- 
cerned, still the treatment would only be palliative and would not as- 
sure the flockmaster that the disease would not break out again. 
Treatment, therefore, of a flock in which scab has appeared must be 
applied to every individual exposed and to the corral and sheep-pens 
in which they have been lodged, and is not only a serious time-consum- 
ing affair, but a most expensive one. 

Treatment.—This is of two Lidde=aphomentive and curative. The 
preventive treatment. is undertaken before, during, and after the 
curative. Indeed, if the flockmaster exercises proper care his flocks 
will never require the curative treatment, for the disease always comes 
from transference of the insect. 

Preventive.—An_ infected flock should be quarantined so that it 
shall not transmit the disease to other flocks, and should be kept from 
public highways where other flocks may pass, until it can be thoroughly 
cleansed and cured. The sheds, yards, and corrals where they have 
been kept should also be cleansed, so that they may not transmit the 
disease. After treatment begins the sheep should be transferred to a 
temporary uninfected yard, so that the old yard may be thoroughly 


60 


disinfected by carting away the soil to some safe spot, by washing all 
the wood-work as high as a man’s head with a solution of boiling lye,* 
and afterwards covering it with a coat of whitewash. All old pelts 
which could harbor the insects should be burned. Every possible se- 
creting place for the insects should be overhauled. After a thorough 
cleansing the yards should be left vacant for three weeks. 

After the dipping the sheep should be driven into fresh, clean yards, 
and not into such as have not been sufficiently cleansed. If possible 
they should be kept from infected pasture ranges for three weeks, by 
which time all parasites which may have dropped from them may be 
considered as dead. Sheep which have been dipped in any of the 
tobacco preparations can be, so it is stated, driven on the ranges im- 
mediately after dipping with impunity, as the tobacco odor keeps the 
insects away. Any sheep which may have died on the range should 
either be buried deeply or burned. In dipping extreme care should be 
taken by all who handle sheep not to transfer the pests from animal to 
animal. 

Medicinal.---There are two methods of treating sheep for scab. The 
one of rubbing poisonous ointments and oils into the fleece by the hand 
is the oldest and least used. It is slow, tedious, and unreliable, and 
has been superseded by better methods. 

The other consists in immersing sheep in watery mixtures which will 
kill the parasites. This method being cheaper, quicker, and more 
effective, is the one in general use in this country. The formule used 
and the methods of applying them vary in different portions of the coun- 
try according to the needs of the sheep-owner. 

In the East, tubs large enough to bold sufticient of the dip to com- 
pletely immerse the sheep, and Kettles or cauldrons of a capacity to 
heat the required amount are used, but in the range country of the 
West, where thousands of sheep are to be treated, especially made dip- 
ping pens and tanks through which the sheep may be driven, and large 
boilers made for the purpose, are used. Each method is adapted to the 
needs of the respective localities. Although some dips are fairly effect- 
ive when applied to sheep with their fleeces on, the dipping should, as 
a rule, be preceded by shearing. This rule should be violated only on 
account of season. If any of the flock are infected all should be sub- 
jected to treatment, otherwise the disease will be carried along and 
break out from time to time. The shearing should take place in a shed 
where all the wool can be cared for, and either poisoned or destroyed, 
or so safely stored that it could by no possibility scatter the insects. 
Any treatment undertaken without being preceded by shearing can at 
best be considered as pailiative. 

The object of the treatment is to kill the parasites and their eggs. 
The parasites are killed by the direct application of a poisonous dip. 
The eggs have a thick shell which often resists the effect of the poison, 


* Use 1 part of potash to 200 of water. 


61 


and the young parasite emerges in due time. They are then subjected 
to asecond dip some six or ten days afterwards, at which time it is pre- 
sumable that all the eggs have hatched and none of the young have be- 
come adult. If the second dip is delayed much longer than twelve or 
- fourteen days, some of the newly hatched larvae may have become adult 
and laid eggs. which may in turn hatch larvee, and become new centers 
of infection. 

All dips, to be effective, contain some ingredients which are poisonous 
to the parasite. This poisonous element may also, if used in too con- 
centrated a solution, be poisonous to the sheep, but this is to be avoided 
by using the dips in the exact proportions of the formula given and 
maintaining these proportions throughout the treatment. In addition 
to the poisonous element, a dip may contain other elements, as water to 
dissolve and to dilute the poison ; also such a substance as alum or soda - 
to combine with the poison, as arsenic, to make it more soluble; or it 
may contain an alkali, as soda or potash, to soften the scabs when ap- 
plied ; or it may contain substances which are empirically added because 
they have been experimentally proven of service. 

The chief poisons used in the dip are tobacco, arsenic, and carbolic 
acid. Of these, tobacco is the favorite, because its use has not been 
followed by the fatality that has in times past followed the use of 
arsenic. Carbolic acid is too expensive to be used in large quantities, 
but is an excellent: ingredient when only a few sheep are to be dipped. 

The addition of tar to these dips is excellent, as the tar water is not 
only good for the wounds but serves an excellent purpose of driving 
away the flies. 

The quantity of dip required for each sheep is variously estimated at 
from 1 quart to 1 gallon. For small numbers of sheep, say fifty or one 
hundred, the larger amount 1s necessary, but for large flocks, 1 quart 
for shorn and 2 for unshorn sheep may be allowed. It is always best 
to have more of the ingredients on hand than is necessary, so that they 
may not be used up before the dipping is finished and thus delay the 
business. To make the dip more effective the solution should be ad- 
ministered quite hot. The most desirable temperature is from 100° to 
110° Fah., which is a comfortable one for the sheep, whose internal 
temperature is about 103°. The warmth enables the dip to penetrate 
the oily wool better, nakes the parasites livelier, and proves far more 
efficient. 

Instead of treating the scab by one application some authorities ad- 
vise the use of a preliminary dip of alkaline water to soften the scabs, 
or of oil or glycerine well rubbed in for the same purpose. This is to be 
followed in two or three days by a poisonous dip. Nearly all advise 
that the scabs should be rubbed with a stiff brush while the sheep is 
being dipped. 

The Australian or Rutherford dip, which has been very successful in 
the hands of large flockmasters, is as follows: Take of tobacco and 


62 


flowers of sulphur 1 pound each, to every 4 gallons of water to be used. 
The tobacco should be steeped in a portion of the water two or three 
successive times so as to extract all of the juice. ° The leaves or stems 
may be used; of the latter three times the weight is required as is 
needed of the former; a press or wringer is convenient to squeeze out 
all of the liquor from them. The sulphur should be mixed with some 
of the tobacco water and stirred until it is of creamy consistency. 
These ingredients should be added to the required amount of water. 
During the dipping this mixture should be constantly stirred and a lit- 
tle fresh water added from time to time to replace that lost by evapora- 
tion. 

This dip, to be more effective, should be heated to between 100° and 
110° Fah. in summer, and 110° and 120° Fah. in winter, never being 
allowed to fall under or exceed these limits. The sheep should remain 
immersed in it from sixty to ninety seconds, and the bead should be 
completely immersed at least once. 

When sheep with heavy fleeces are dipped it will be found necessary 
to separate the fleece with the hands, that the fluid may permeate better. 
Hight or ten days after the first dipping the treatment should be re- 
peated. Sometimes a third and more rarely a fourth dipping is neces- 
sary. When the iast two are required it is most often due to care- 
lessness in preparation, or a failure in the strength of the first dips. 
Sometimes it may be necessitated by the rain having washed off the 
first solution soon after dipping. 

Australian sulphur and lime dip: Take of flowers of sulphur 100 
pounds, of quicklime 150 pounds, water 100 gallons. Mix and stir 
while boiling for ten minutes, until the mixture assumes a bright red 
color, then add 3 gallons of water. Hold the sheep in the mixture until 
the scabs are thoroughly soaked. Immerse the head at least once. Use 
the dip at 100 to 110° Fah. Dip twice at an interval of two weeks. 

In the American Merino, 1887, Stephen Powers gives an excellent 
description of sheep-dipping on a large scale, and the following recipes 
in use in various sections of the United States: 

Texas and New Mexico: Thirty pounds of tobacco, 7 pounds of sulphur, 3 pounds 
of concentrated lye, dissolved in 100 gallons of water. 

Nevada: sulphur, 10 pounds; lime, 20 pounds; water, 60 gallons. 

California: Sulphur, 4 pounds; lime, 1 pound; water, enough to make 4 gallons. 

Kansas: Sulphur, 22 pounds; lime, 7 pounds; water, 100 gallons. 

Sulphur and lime is probably the cheapest recipe, but the lime is apt to injure the 
staple; still this recipe appears to prevail over all others in the scab-infested 
regions. Probably tobacco and sulphur form the best combination known for the 
‘treatment of scab. To every hundred gallons of water there should be used 35 pounds 
of good strong tobacco (if stems or other inferior parts are used there should be 
more), and 10 pounds of flowers of sulphur. This preparation used at a temperature 
of 120° Fah., will kill all acari ticks and lice, and leave the wool in a healthy con- 
dition. To insure thorough work apply a second time in ten days or two weeks, 


63 


Walz’s dip, one of the oldest recipes, is as follows: Take of fresh 
slaked lime 4 parts, carbonate of potash 5 parts, mix and boil in barn- 
yard water; add animal oil 6 parts, tar 3 parts; dilute with barn-yard 
lees 200 parts, water 800 parts. To-day this recipe is more curious than 
useful; one of the ingredients is not on the American market, and an- 
other i is offensive. Veterinarian Clok, in his Diseases of sien, 1861, 
reports this mixture as being too weak for old cases, and recommends 
the following modification: Take of freshly-burned slaked lime 6 
pounds, add potash 6 pounds, and water 10 quarts; boil an hour, stir- 
ring occasionally. Add pine-oil 8 pounds, and tar 2 quarts, stirring the 
mixture thoroughly. Make an infusion of 20 pounds tobacco in 130 
quarts of water; add the lye already made andstir. This quantity suf- 
fices for one hundred sheep. Apply by immersing the sheep, separat- 
ing the wool and breaking the scabs. Repeat in eight or ten days. 

Law’s recipe (Farmers’ Veterinary Adviser) is a very good one: Take 
of tobacco 16 pounds, oil of tar 3 pints, soda ash 20 pounds, soft soap 4 
pounds, water 50 gallons. This quantity suffices for fifty sheep. The 
tobacco should be steeped; afterward the other ingredients should be 
added at 70° Fah. 

Zundel’s dip is available, but Dr. Kaiser (Auhrverfahren bei der Schaf- 
réude, 1883) reports that it is too weak in cases of long standing. It is 
said to leave the wool clear and white after using. For every one hun- 

‘dred sheep take crude carbolic acid 3 pounds, caustic lime 2 pounds, pot- 
ash 6 pounds, black soap 6 pounds, and water 70 gallons; mix and boil. 
Dr. Kaiser has obtained excellent results from a modification of this 
recipe. ‘Take of tobacco 5 kilograms (134 pounds), infuse it in 250 liters 
or 66 gallons water; dissolve in it 3 kilograms (8 pounds) soda, add 14 
kilograms (4 pounds) freshly burned and slaked lime. Dilute 3 kilo- 
‘grams (8 pounds) black soap (soft soap will do) with hot tobacco broth 
and add it to the rest; then add 14 kilograms (4 pounds) crude carbolic 
acid, which contains at least 50 per cent. of the pure acid. Mix. This 
quantity is sufficient for one hundred sheep. 

Gerlach’s dips, which are administered at two different times for a 
single treatment, are cheap, but owing to the time and labor to be ex- 
‘pended in performing an operation twice which in other instances is 
done but once, is much more costly than those which require but one 
application. 

Take of potash 2 parts, burnt lime L part, water 50 parts. Mix. Use 

this dip for softening scabs. Follow it in two or three days by the fol- 
lowing: Make an infusion of tobacco 34 pounds in 66 gallons water, by 
slowly steeping the tobacco in a portion of water and finally adding it 
to the remainder. Repeat the dip in from six to ten days. 
_ Roloff’s dip, for a mixture sufficient for one hundred sheep, is: Take 
7.5 kilograms (20 pounds) of tobacco, steep it with 250 liters (66 gal- 
lons) water for half an hour, heat it to 30° R. (95° Fah.) and add 1 
kilogram (25 pounds) each of puré carboli¢ acid and of potash, 


64 


A cheaper and fully as effective dip of similar formula is the follow- 
ing: Mix an infusion of 15 pounds tobacco with 1 kilogram (24 pounds) 
carbolic acid and 5 kilograius (185 pounds) wood tar, pour it into 250 
pounds (66 gallons) water at 40° R. (125° Fah.), in which 3 pounds 
soda has been dissolved. Use it at a temperature of 80° or 90° Fah., 
and repeat in six or seven days. 

There are three arsenical dips favored by European authorities, the 
Jast of which might be used while exercising proper care and precan- 
tion. The solution should always be kept as dilute as the formula calls 
for. The sheep should not be allowed to drain on the grass, but should 
be kept up until nearly dry, and the laborers who dip should grease 
their arms with linseed-oil before beginning work. 

Tessier’s dip, the oldest, was proposed in 1810, To make a mixture 
for one hundred sheep, take arsenious acid 35 pounds, sulphate of iron 
20 pounds, and water 190 pounds; boil. 

Tessier’s dip causes a discoloration of the wool, which can be removed 
by washing with soap, but it is on this account more or less objectioua- 
ble, and to overcome this objection Clément has modified it as follows: 
Arsenious acid, 1 part; sulphate of zine, 5 parts; water, 100 parts. 
The water is put over the fire, the medicinal substances added, and it is 
allowed to boil for eight or ten minutes. After the temperature has 
fallen to the proper degree it is ready for use. The sheep is entirely 
submerged in the liquid, with the exception of the head, the udder of 
ewes suckling their young having been previously covered with some 
fatty substance to prevent the action of the astringent on the skin and 
on the secretion of milk. 

Matthews dip: Take arsenious acid 1 part, alum 10, and water 100 
parts. , 

Scheurle and Kehm’s dip: Take arsenic 1 part, alum 12, and water 
200 parts. This latter is weaker than the former, and therefore safer. 
Moreover, it is claimed to be as effective. 

The sheep dips that are put upon the market are objectionable for three 
reasons: First, their formulas are not given; second, the preparation 
may be valueless, or if not valueless of ingutficient strength; and third, 
the preparation may cost more than it is actually worth. Should the 
dip be put up by reliable houses, and have their formulas printed on 
the outside of the package, the prepared article might prove better 
compounded and absolutely cheaper than the flockmaster could pre- 
pare it. 

Police sanitation.—It is not sufficient that the flockmaster thoroughly 
cures his flock, disinfects his sheds and quarantines his place. Another 
duty awaits him, and that is a public one. All flock-owners should 
unite and assist the State in improving and carrying out its sanitary 
laws. Nearly all States have laws regarding the suppressing and 
quarantining of sheep infected with scab, but they seem to lack in 
stringency and are therefore inadequate. Laws compelling strict quar- 


65 


antine and public supervision of the treatment, at the expense of the 
owner. even though it is undertaken by the State, are demanded for 
the complete eradication of the disease. With such laws no one could 
long harbor on his premises a disease which constantly threatens the 
flocks of his neighbors with destruction and their owners with financial 
ruin. 


FOOT SCAB. 
CHORIOPTES COMMUNIS, Verheyen, var. OVIS. 
’ yen, 


This variety of scab, which is due to Chorioptes communis, Verheyen, 
var. ovis, is of rare occurrence. It has been noticed and studied in Ger- 
many by Ziirn. 

The seat of this disease is in the feet and limbs. The disease pro- 
gresses very slowly from the feet, and little by little invades the upper 
parts of the limbs and adjoining parts. Itis not readily communicable 
to other sheep and spreads slowly. 

In the beginning this variety of scab is characterized by the redden- 
ing, followed by an abundant scaling of the skin, and later by yellowish 
white crusts. The animals stamp, scratch, and bite the parts, showing 
anintense itching. As the disease progresses the crusts become thicker ; 
cracks may form in the folds of the pastern and the limbs become quite 
unsightly. The parasites swarm beneath the crusts, and when found 
form a certain symptom of the character of the disease. 

Foot-seab is not a serious malady, as it readily yields to treatment 
and is of slow extension. Any of the remedies proposed for the treat- 
ment of common scab may be used with good effect. 


23038 A P i) 


Fig. 
Vig. 
Fig. 


Vig. 


N 


PSOROPTES COMMUNIS First., var. OVIS. 
PLATE VII. 


1. Adult male, dorsal view: a, head; b b, legs; ec, suckers. 
2. Adult male, ventral view. 

3. Adult female, dorsal view. 

4. Adult female, ventral view. 


OTE.—Figs 1 to 4, Plate VII, and Figs. 1 to 3, Plate VIII, are equally magnified. 


PLATE VII 


A. Hoen & Co, Lith. Baltimore. 


PSOROPTES COMMUNIS, Var OVIS, 
(The Common Scab-Mite.) 


_ 


Bow 


68 


’ 


PSOROPTES COMMUNIS Fiirst.. var. OVIS. 


Popo WANNE 


Young female before moulting for the last time. 

Egg drawn from a specimen whick was inside an adult female. 

Young six-footed larva. 

a, open, and b, closed sucker of Psoroptes from ears of rabbit; c, the rod which 
connects the membrane on the end with the muscles which close the 
sucker. 

Two views of the mandibles. The lateral spurs, a, a, point outward 
(Megnin). 

Head and anterior limb enlarged; ventral view: a, mandibles; b, antenne; 
c, maxille; d, membrane joining the antenne ; e, e, e, joints of the limb; 
Jf, the claw ; g, the ambulacrum or sucker. 

Male and female of Psoroptes communis var. equi (Megnin), 


PLATE VIII 


. Baltimore. 


A Hoen & Co. Tith 


) 


PSOROPTES COMMUNIS, Var OVIS, 
(The Common Scab-Mi 


THE PENTASTOMA. 


LINGUATULA TANIOIDES, Rud. 


See Plate XVII, figs. 1-6. 


Linguatula tenioides is also known under the names Linguatula rhi- 
naria, Pilger, and Pentastoma tenioides, Rud. 

In describing this parasite, Neumann’s excellent description in Traité 
des Maladies Parasitaires, page 491, has been taken as a guide. The 
species is probably present in this country, as in two instances the larval 
form known as Pentastoma denticulatum has been found. The larvee were 
found by Dr. F. L. Kilborne, of this Bureau, in a rabbit, some time in 
the summer of 1887, and once by myself in another rabbit in 1888. 

This curious parasite is classed among the Arachnids, being more 
closely related to the spider and mite family than to any other. The 
order Lixguatulide, to which they belong, is thus defined: 


Endoparasitic arachnids with elongate, vermiform, annulate body. Mouth want- 
ing jaws in the adult state, and surrounded by two pairs of hooks representing rudi- 
mentary feet. No heart. Respiration cutaneous. In it are two genera: (1) Lingua- 
tula, Frohlich, which has the body depressed with dorsal face rounded and with the 
borders crenulated. The cavity of the body forms diverticula in the lateral parts of 
the rings. (2) Pentastoma, Rud., which hasa cylindrical body and the cavity of the 
body continuous. It is not represented in our domestic animals, unless it be a lar- 
val form found once in the peritoneal cavity of a dog. 


Description.—The species met with in the domesticated animals has 
the following characters: 


Body white, lanceolate, very elongate, worm-like, depressed dorso-ventrally with 
the ventral face nearly plane and the dorsal face convex. Anterior extremity 
rounded, large ; posterior extremity attenuated. Cephalo-thorax short, solidified in 
all its width to the abdomen, from which it is scarcely distinct, and which forms by 
far the larger part of the body. Integument showing about ninety rings, larger in 
their middle; these make the borders of the body crenulated. Hooks acute, re- 
curved, twice-jointed, the basal joint attenuated in its deep part. These hooks, each 
retractile in a pocket, are moved by muscular bundles which act in opposite direc- 
tions. Mouth sub-quadrangular, rounded at the angles; digestive tube simple, rec- 
tilinear; anus terminal. Male, white: length from 18 to 20™™"; width, in front, 3™™; 
behind, 0.5™™, provided with saccular testicles which fill the body cavity even to the 
anterior fourth. Female, whitish grey, often rendered brown by the eggs along the 
median line where the integument is thin and semi-transparent; length from 8 to 
10; width, in front, from 8 to 16™™, and behind, 2™™. Eggsovoid; length, 0.09™™; 
width, 0.07™™, 


Life history.—The female Linguatula tanioides lays its eggs in the 
nasal cavities of the dog. These are scattered on the ground and grass 
69 


70 


where they lie until eaten by some herbivorous animal. The shell is 
then dissolved from around the embryo, and it bores through the walls 
of the stomach or intestine into the mesenteric gland, liver, or lung, 
where it encysts itself. In its first stage of active migration the larva 
resembles the Acari (Plate XVII, Fig. 4). It has an ovoid body, flat- 
tened on the ventral face, rounded on the dorsal. Its posterior extrem- 
ity is narrowed and dentate. It is furnished with two pairs of articula- 
ted, two-clawed feet, and at its anterior end by a perforating apparatus 
formed of a median stylet and two re-curved hooks. Its length is 
0.138™"; its width 0.06™™. 

Having arrived at the mesenteric glands, the liver, or the lungs, as the 
case may be, the embryo loses its feet and is transformed into an im- 
movable pupa (Fig. 5), without segments, hooks, or hairs, measuring 
0.250 to 0.300" long, and 0.180™™ in width. 


It emerges from this cyst transformed into another larva by a series of successive 
moults (see Fig. 6). The body is elongate, larger forward, and is divided into eighty 
to ninety rings bordered behind by a series of fine spines. The digestive tube is 
large, the mouth is elliptical, and surrounded with four characteristic hooks and with 
accessory hooks. The larva isagamic, its genital organs being rudimentary and rep- 
resented only by a little granular mass in the posterior part of the body. ‘Towards 
the sixth or seventh month the larva is completely developed, measures 6 to 8™™ long, 
and is in the stage called Linguatula denticulata, 

These larve liaving escaped from the eyst, fall into the serous cavities and remain 
there for some time. They eventually escape, but the precise method is unknown. 
Next they are seen in the nasal cavities of dogs. Exceptionally, so it is said, they 
are found in the nasal cavities of sheep and cattle, into which they have wandered. 
These larve can acquire their full development only in the respiratory passages. Once 
installed in the nasal cavities they develop into egg-bearing adults. The males wan- 
der and can be found at various points of the cavities, but the females are more 
sedentary, and are never found in the ethmoidal cavities. After the death of the 
host they may travel into the pharynx and larynx. They exceptionally introduce 
themselves into the frontal sinuses. They are generally found at the bottom of the 
nasal chamber. 


As the adult stage is not usually found in sheep, and as its occurrence 
is problematical in this country, the disease it causes will not be con- 
sidered in this volume. 

Disease.—The young state, Linguatula denticulata, found in eysts 
within the glands, ete., are said to be particularly frequent in sheep in 
Europe. Sheep in which the parasite affects the mesenteric glands are 
generally less fat; their flesh is paler, and they are apparently predis: 
posed to anemia. These glands show no evidences of the parasite at 
first, but later they grow browner, smaller, and are crossed by galleries 
filled with larvae. These cavities are separate at first, but finally com- 
municate; the substance of the gland is destroyed and transformed into 
a brown tumor, in the middle of which are the Linguatule. From these 
the parasites often escape through openings with irregular borders; at 
other times the surface is covered by dark, irregular spots, fibrinous de- 
posits, and false membranes, which indicate a recent departure or a de- 


im 


struction of the embryos. At last the tissue is found thickened, indu- 
rated, and offers here and there tuberculoid grains formed from the old 
nests of Linguatule. These altered glands are destroyed and are of no 
further use in nutrition. The larvee create further troubles in their mi- 
grations, but so little is known about these parasites that little can be 
said. 

There is no treatment. Prevention is also difficult. If it should be 
learned that we have these parasites here in considerable numbers the 
best remedy would be to remove the dogs, which are certainly the cause 
of large numbers being scattered in Europe. 


IMMATURE TAPE-WORMS—BLADDER-WORMS. 


Plates IX, X, and XI. 


Besides the adult tape-worms found in the intestines of sheep, there 
have been four other species described which infest various portions of 
these animals in their immature stages. These species are Tenia mar- 
ginata, Batsch, T. coenurus, Kiich., 7. echinococcus, v. Siebold, and T. 
tenella, Cobbold. The forms found in sheep were first described as 
Cysticerci, and have since been known as Cysticercus tenuicollis, Coenurus 
cerebralis, Echinococcus and Cysticercus ovis, respectively. 

All these species resemble each other in their anatomical structure, 
their growth, and their life history. They differ in minute structure, in 
invading different portions of the sheep, and in the effects they produce 
on the animal. 

Tenia marginata is more common in the United States, and 7. coenurus 
next. Neither of the other two species have been found in sheep in this 
country. 


TANIA MARGINATA, Batsch. 
Plate IX. 


Tenia marginata ocewrs in sheep as a little semi-transparent bladder 
filled with liquid, varying from a very minute size to a bag an inch or 
more in diameter, but usually having a diameter of a half or three- 
quarters of an inch. 

Occurrence.—This tenia, in its eysticercal stage, is usually found be- 
tween the layers of the serous membrane which form the omentum, or 
‘‘caul” of the abdominal cavity. It may be found in the liver, espe- 
cially within a week or two after the infection of the sheep by it. A very 
common place to find it is between the folds of serous membrane which 
suspends the intestine in the pelvic cavity. When one of these little 
fluid-saes are found it may be cut out, with the surrounding tissue for 
examination. Afterwards great care should be taken in dissecting the 
serous tissue, which forms an outer sac, so that the eysticereus within 
shall not be cut, its contents allowed to escape and its walls to collapse. 

Description of cystic stage —The smalier bladders are apparently com- 
posed of a semi-translucent whitish membrane, at one end of which may 
be seen a whitish thickening. As the bladders grow the walls become 
slightly thicker and thespot at the end becomes much larger and pro- 
jects in the form of a knob. 

72 


73 


When the animal is placed in a saucer of lukewarm water immedi- 
ately after its removal from the slaughtered sheep and examined, it 
can, by the aid of a low-power lens, be seen to possess considerable 
peristaltic movement. This movement is produced by bundles of 
muscles lying at right angles to each other, which may be seen appear- 
ing as a faint striation on the surface. 

The little knob end of the bag is its essential part, and contains what 
is to develop into the future tania. Sometimes the animal will extend 
this knob into a cone, and finally thrust out of its center the very tip 
of the cone. By careful handling this so-called head end may be 
squeezed out by the fingers. The tip, when examined by a magnifying 
glass, can be seen to possess four cup-like spots, with a little glittering 
circlet of hooks between them at the very apex of the cone. 

Life history.—When these cysts have attained their hooks and cups 
in a well developed condition, they are ready for transplanting into 
another animal or host. The cysticercus completes its development in 
about eight weeks. It may live a long time after this, and its cyst 
enlarge, but the modifications it may undergo are unessential. The 
host within which the cysts or cysticerct generally develop is the dog. 
They may, however, also develop in other carnivora, such as the wolf 
or coyote. 

Their emigration is a passiveone. They remain encysted where they 
are found until the sheep is slaughtered and the dogs eat the offal, or 
until the sheep is killed by a dog or wolf and its liver is torn from its 
place and devoured, together with any of the cysticerci which may be 
attached. Uaving gotten into the intestines of the host the parasite 
completes its development, becomes adult, and finally produces young, 
which pass from the host along with the ejecta of the intestines. 

The young at this stage are egg-like.. They are very small and 
hardly visible to the naked eye. When viewed with a glass they are 
seen to be a minute, jelly-like mass, furnished with six hooks and sur- 
rounded by at Jeast three membranes. The outer is thin and fiiled with 
fluid; the inner two more closely surround the embryo, and confine be- 
tween them an oily material which serves to protect it when exposed to 
the atmosphere. 

After passing to the ground these embryos in some way, possibly by 
adhering to food or by floating in drinking water, make their way into 
the sheep. When they arrive in the abomasum, or fourth stomach, it 
is supposed that the gastric juice digests the membranes surrounding 
the embryos and they then begin their active wandering. At this stage 
they penetrate the walls of the fourth stomach and make their way 
between the walis of serous membranes to the place where they finally 
find lodgment. This active migration must often be converted into a 
passive one after the embryo has made its way through the mucous 
coat of the stomach, for when the embryos have been fed in large num- 
bers to the sheep in the course of the experiments of different investi- 


74 


gators the liver has been found to be filled with multitudes of them. 
One investigator has found them in the minute branchlets of the portal 
vein, which conducts the blood from the stomach and intestines to the 
liver. Now, in order to appear in the liver and in the portal vein in 
such numbers the embryo must make its way into the little branches or 
‘apillaries which collect the blood at the stomach, and then be washed 
by the blood current into the liver. When they become lodged in the 
liver they again migrate actively and tunnel through the mass of the 
liver in alldirectious. The little channels are made slowly. They begin 
as a minute point, and become gradually larger as the parasite increases 
in size and changes its position. About the ninth day after the embryos 
have been swallowed some of the parasites may be as large as a flax- 
seed; most of them will be smaller. They will then be little oval water- 
aes with a whitish thickening at the end. 

Home of the parasites seem to pass the entire length of the intestine 
before they penetrate the walls; but when they reach the rectum they 
pass through, and, becoming Todaed between the layers of serous mem- 
brane, develop there. This probably accounts for the presence of the 
considerable numbers which are found in the pelvis. 

The destination at which these parasites arrive has its influence on 
their development. When they have migrated to a point between 
serous tissues which may be easily spread apart, and offer little resist- 
ance to the growing parasite, a certain proportion of them seem to 
thrive and arrive at a stage in which they may continue development 
by the proper exchange of hosts. If this exchange is not effected the 
parasite may remain unharmed for a long time while awaiting this 
opportunity. Should they die from any cause a slow change in the 
appearance of the parasite is noticed. The flaid it contains becomes 
milky and limy. The serous sac surrounding it becomes thicker; finally 
such changes have occurred that in place of a soft sac a round, hard 
sphere of lime covered by a thick membrane may be found. ‘The re- 
mains of the parasite may still be seen by careful dissection between 
the cover and the limy deposit. 

But when, on the other hand, they arrive at the liver they seem to 
have reached a place of destruction; for if they do not kill the invaded 
host within two weeks, a period long before they could continue their 
life in another host, thesame degenerative processes seem to affect them, 
in their earlier stages, which destroy the older individuals in other or- 
gans of the body. This seems in part due tothe pressure which the liver 
cells anid capsule exert upon them. These statements seem substanti- 
ated by the presence of either sears or calcareous nodules in the liver 
and of no large cysticerci, except where the loose serous membrane may 
have permitted their growth. 

These parasites have occasionally been observed in other parts of the 
system than those mentioned, as in the lungs, heart, and muscles. 

Disease.-—The harm that Tania marginata does in its young stage 
depends much on the degree of infection. In experiments animals have 


15 


been killed in from nine to twelve days after feeding. In such cases 
the sheep usually die of hemorrhage from the liver and peritonitis. This 
is caused by the perforations of the serous covering of the liver due to 
the parasites. These experiments show that the parasite is injurious to 
sheep. The presence of a few well-advanced cysticerct in nearly all of 
our sheep also shows that though the .parasite may be injurious in its 
young stages, the sheep rarely succumbs to them in their period of inva- 
sion. After a period of about two weeks the sheep seem to have no dis- 
comfort from them. 

Sheep may be invaded by the tenia at almost any time of the vear. 
The winter season, when the embryos which have been scattered by the 
dogs become frozen, seems to be less favorable. If the dogs have 
access to the sheep-pens ev en this season will not delay the infection. 
Lambs and yearlings appear to be most subject. Three months’ lambs 
are the youngest in which the cysticerci have been found. Experi- 
ments in attempting to produce the cysts in old sheep by feeding gen- 
erally fail. Young sheep furnish the best specimens, while in five or 
six year old sheep the cysticerct seem to have degenerated into calea- 
reous nodules. 

’ The adult tenia live in dogs. Soon after the cyst is swallowed the 
tissue is digested from it, and the large, watery bag, which has prob- 
ably already lost its flhid in the mastication of the food, disappears. 
The head remains, and passing from the stomach into the intestine at- 
taches itself by its hooks and cups, which serve as suckers. Here the 
parasite, bathed in the intestinal fluids which nourish it, proceeds with 
its development. In a day or two it lengthens and begins to show 
cross lines, which indicate the points where the division into segments 
is to occur. Later the segments appear and the worm gradually ma- 
tures the organs of reproduction in them. After ten or twelve weeks 
have passed, the parasite begins to lose its end segments, which have 
fully developed embryo in them, and are ready for the infection of sheep. 

Description.— Tenia marginat a, Batseh, or Tenia cysticerci tenuicollis 
Kiich., is the largest of the tenia infesting dogs. It is usually, when 
mature, about a yard long. Large specimens may be stretched, when 
fresh, until they are 24 yards long. The greater number of specimens 
are, when contracted, under a yard long. The width of the worms also 
depends on their degree of contraction, the more contracted specimens 
being the widest. The average of relaxed specimens is about two-fifths 
of an inch. The same specimens, when alive, might contract so much 
as to measure three-fourths of an inch. The width of the worm gradu- 
ally widens from its bead for four-fifths of its length, and then contracts 
slightly totheend. This species is moderately thick, neasuring a little 
over a twenty-fifth of an inch where thickest. When first taken its ap- 
pearance is white and opaque, but when kept in water it becomes par- 
tially transparent. It then resembles a whitened, pliable band of geia- 
tine. Atits small end is the so called head, which is separated from the 


76 


body by seareely any constricted neck. The head is quadrangular, is 
about one-twenty-fifth of an inch in diameter, and has a circlet of from 
thirty-two to forty hooks at its apex, and four moderate sized suckers. 
The specimen figured contained twenty-eight. These hooks and suck- 
ers serve to anchor the parasite to the intestinal walls. The neck is 
short, and at a little distance from the head shows the division into seg- 
ments which become plainer and plainer towards the end of the body. 
The segments are at first very short and broad, but gradually lengthen- 
ing become square where the animal is widest when relaxed, and about 
twice as long as broad at the end. The terminal segments measure 
about one-fourth of an inch wide and one-half inch long. There is no ali- 
mentary tract, the office of absorption of food being filled by the skin. 
Motion is effected by muscular bundles situated beneath the skin, which 
give a variety of vermicular movements. <A primitive nervous organi- 
zation has been described. The entire length of the worm is traversed 
by two canals connected in each joint by a cross system. This system 
is said to serve as an excretory apparatus. It has been called a vascular 
system. Each adult segment contains a complete hermaphroditic gen- 
erative apparatus. They begin to appearin the fiest third of the animal 
and gradually mature toward the last segment. At about the middle 
the eggs become fertilized and develop until the end. The terminal seg- 
ments when ripe separate and pass away. In this way the segments, 
which were once near the head, become central and finally terminal, 
growing adult, maturing their embryo, and passing away in turn. The 
embryonic shells are 0.036™, about one-seven-hundredths of an inch 
thick. The embryo is six-hooked. These worms mature and liberate 
segments in the dog in about ten or twelve weeks after the cysticercus 
has been swallowed. 

Occurrence.—The marginate tape-worm is found at about the middle 
of the small intestine, therein differing from Tania serrata, T. cenurus, 
and 7. cucumerina, which live nearer the end of the small intestine. 
They may be found in dogs of any age. Shepherd or collies, hounds, 
and slaughter-house dogs are most liable to be infected. City dogs, 
which have but little opportunity of being infected, rarely contain the 
parasite. 

Disease.—The harm that the parasite does the dog seems to be in- 
considerable. Were it not that the cysticercal stage does harm to sheep, 
it might well pass unnoticed by the flock master. The ease with which 
one can rid his dogs of the parasite seems to place the destruction of 
the species in his hands. For Tenia marginata alone the administra- 
tion of an effective tenicide every two months would be sufficient; 
but as 7. cenurus develops in three or four weeks, it would be best to 
treat for both at once and dose the dogs more frequently. 

Diagnosis.—Every sheep-owner should proceed to dose his dogs with 
worm medicine, whether they are known to have tape-worms or not. 
The diagnosis of tape-worms in dogs is difficult, those having many 
often showing no symptoms. Sometimes they may be suspected from 


CG 


the leanness of the animals or from the little white segments they pass. 
Such are the benefits arising from thorough medication that the time 
and expense given is well laid out. 

Medical treatment.—The method of treatment consists in tying the 
dog and withholding its supper, not water, over night. Some admin- 
ister a physic at this time. The special worm medicine chosen should 
be given on the next morning, and followed two hours later by a dose 
of physic. The worms, if the treatment has been effective, should be 
voided inside of twelve or eighteen hours. The dog should be fed 
sparingly for a day or two preceding the operation. The preparatory 
physic may be omitted. The dog may be fed at noon on milk or meat. 
He should not be loosened until the following day. The excreta passed 
should be burned or buried in some safe place. The method of admin- 
istering the medicine is as follows: A man of whom the dog is not 
afraid should place himself in a corner and back the dog between his 
legs. He should then grasp the muzzle gently but firmly in one hand: 
with the other hand should pull out the loose cheek at the corner of the 
mouth. Into the pocket thus formed an assistant can put the medicine, 
a dessert-spoonful at a time. The lips should then be held close, and 
the dog will usually move his tongue sufficiently to swallow the dose. 
Should he refuse, his nostrils may be closed for a second or two until 
he gasps for breath, when the medicine will be swallowed. If any con- 
siderable quantity is to be given the operation should not be hurried, 
and should be persevered in with care and patience. Soime dogs will 
eat their medicine mixed with milk or soup, while others are very fas- 
tidious. 

Areca nut has proven itself the best tenicide for dogs. The freshly 
ground powder is the best. The rule for measuring the dose is to allow 
two grains of the powder to each pound of the dog’s weight. The powder 
is thoroughly stirred with soup or milk. If refused, another dose may 
be prepared by mixing it with butter or molasses until the mass is quite 
soft, and administered by hand. Follow the medicine in two hours by 
a table-spoonful of castor-oil for a moderate sized dog. The oil can be 
given alone or well shaken and mixed with three times the quantity of 
milk. 

If areca nut is not available, a dose consisting of a tea-spoonful of tur- 
pentine and two table-spoonfuls of castor-oil, thoroughly mixed with a 
coffee-cup full of milk, may be substituted. This dose is one for an 
average-sized farm dog. The final physic is not given in this case. A 
2-ounce dose of castor-oil will bring away portions of the tape-worms, 
and sometimes the heads, without the aid of other worm medicine. 

Finlay Dun recommends the following prescription: Take 20 drops 
of the oil of male-shieldfern, 30 of the oil of turpentine, and 60 of ether. 
Beat them together with one egg and give to the dog in soup. 

Ziirn advises the use of about 4 drams of freshly powdered areca nut 
for a very large sized dog, 25 for a medium sized, and 1 dram for a very 


78 


small dog. The powder is to be rubbed up with butter. Follow in two 
hours by a table-spoonful of castor-oil. 

Dr. Hagen advises treatment of all sheep dogs each spring and fall, 
ihereby claiming an increased immunity for the sheep from the cysticerct. 
He recommends the following: Take of the oxide of copper $0 grains, 
of powdered chalk and Armenian bolus 40 grains each ; of water suffi- 
cient to mix the ingredients into an adherent mass; divide into one 
hundred pills; administer one three times daily for ten days by erush- 
ing them ina piece of meat or bread and butter. 

In addition to other remedies Roll prescribes the following: (Kach 
dose is for large dogs. For smaller ones proportionately less ought to 
be given.) (1) Extract of male-fern and the powder of male-fern, 2 
drams each. (2) A decoction of 23 ounces of pomegranate-root bark in 
water, reduced to 6 fluid ounces, and add 1 dram of extract of male-fern, 
to be given in two doses an hour apart. (3) From one-half to 1 ounce 
kousso formed into pills with honey or molasses, and a little meal. (4) 
From i$ to 24 drains of Kamala stirred with honey or water, and given 
in two doses inside of an hour. He advises a preliminary preparation 
by feeding the dogs sparingly for two or three days previous on salted 
food, and the administration of eastor-oil the evening before. The rem- 
edies proposed are to be mixed with some material to make them fairly 
acceptable to the patients. With the exception of kamala, which acts 
as a cathartic, all should be followed in two hours by eastor-oil. 

After any treatment the patients should be fed with some liquid diet 
on the first day. After this they may receive any wholesome food. 

The necessity of repeating a treatment depends entirely on the 
efficacy of the first, and the care exercised in preventing a re-infection. 
If the treatment has been successful in removing the worms, heads and 
all, of course no further treatment will be required. If only portions 
have been removed, then another desing is necessary. Tor tenia mar- 
ginata another treatment need not occur under eight weeks, for the 
tape-worm is harmless as far as sheep are concerned up to that period, 
for, as far as is known, the worm will not throw off segments before that 
time. For 7. cenurus the treatment should be repeated in about two 
weeks. 

Preventive treatment.—The great resource of the flockmaster lies in 
prevention. In this he has nearly absolute control over the health of 
his sheep, in so far as Tenia marginata and T. conurus are concerned. 
As the dogs can only get these tania from eating viscera of the sheep, 
all the viscera of slaughtered or dead sheep should be withheld from 
them, and either buried, burned, or rendered. 

Police sanitation.—Sheep-killing dogs should be destroyed. Each 
owner should keep his dogs at home, so that all strange dogs may be 
killed in order to prevent them from harming sheep and scattering the 
tenia eggs far and wide over the pastures and in the drinking places. 
Dog laws ought to be made sufficiently stringent and adequate for the 
protection of sheep. } 


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TANIA MARGINATA, Batsch. 


PLATE IX. 


. Adult tenia, natural size: a, head (the constricted part following is the 


neck); b, point at which the reproductive organs begin to develop ; ¢, ¢, ¢, 
adult segments either separated or about to separate. 


. Head: a, the crown of twenty-eight hooks; b, b, the suckers or bothria; ce, 


the neck, which is transversely wrinkled, but not segmented. 


. Crown of hocks enlarged: a, a, large hooks; b, b, alternating small hooks. 
. Form of single hook. 
. Bladder or Cysticercus tenuicollis (taken from the omentum or caul of a sheep), 


which produces the tenia whén fed to a dog: a, the head; b, the bladdery 
portion filled with fluid. 


. Head of Fig. 5, enlarged, shows the opening from which the true head may 


be evaginated. 


. Head of the cystic worm, evaginated, shows the suckers and crown of hooks. 
. Segment from near d Fig. 1 shows the branching uterus which is filled with 


Ova. 


PLATE IX 


A.Hoen & Co, ith. Enltimore. 


TANIA MARGINATA, Batsch. 


PLATE X. 


Fig. 1. Portion of a liver from alamb which died nine days after feeding with the 
embryo of Tenia marginata, drawn from an alcoholic specimen; natural 
size. The surface is seen covered withshort ridges, which run in all diree- 
tions, and are more numerous toward the thin edge of the liver. 

Fig. 2. Cross-section taken at aa, in Fig. 1, shows the round cross-sections of the 
burrows made by the young embryos; also oblique and longitudinal see- 
tions of them. The lower edge is rough and terminates in liver substance, 
not in the capsule. 

Fig. 3. Young embryo or cysticerci: a, natural size; b, x6. 

Fig. 4. Embryo in the state in which they are fed to the lamb to produce the disease. 
(Leuckart), 550. 


PLATE X 


S altimore 
uthoceust altimor 


GID OR STAGGERS. 


TANIA CasNURUS, Kiich. 
Plate XI, Figs. 1 to 4. 


The disease which is popularly known as gid, sturdy, staggers, or 
turnsick in sheep, is caused by the presence of a parasite living in the 
brain. This parasite is closely related to Tania marginata. It lives in 
about the same way, but differs from it in detail. Itis knownas 7. 
cenurus in its adult state, and as Cwnurus cerebralis in its cystic state— 
the stage in which itinfests sheep. 

Method of infection.—Sheep become infected with this dangerous para- 
site while pasturing or drinking where dogs have scattered tie eggs in 
their wanderings through the country. In the West the eggs may also 
be scattered by the wolves, coyotes, and foxes, which may harbor the 
adult parasite. 

Life history.—The eggs of Tenia cenurus, after being taken with the 
food or drink, are hatched within the stomach of the sheep and make 
their way through its walls. They then migrate either actively, by 
forcing their way through the connective tissues, or passively, as is 
generally believed to be the case, by getting into the circulatory system, 
and are carried from thence into various portions of the body. Those 
arriving in the spinal canal and cranial cavity seem to thrive and grow, 
while the others, which may have reached the heart, lungs, and dia- 
phragm, grow for a time and then perish. 

_ Description of cystic stage —Having arrived in the brain cavity, the 
young embryo migrates upon the surface of the brain much as the em- 
bryo of Tenia marginata does through the liver substance. The gal- 
leries it makes are sinuous. They begin at a point and slowly increase 
with the growth of the parasite and run inany direction. In from two 
fo three months after the first invasion of the brain the cysts have 
grown as large as a hazel-nut, or about a half inch in diameter. When 
examined closely they will be found incased in a thick outer skin, a sac 
made by the membranes ot the brain. Out of these sacs the parasites 
may be loosened, and these resemble the cysts of 7. marginata. It 
differs, however, in a very important particular—instead of having a 
single knob attached, tens or hundreds of these knobs may be seen as 
little dots hanging from the inner surface into the fluid of the cavity, 
(see Figs.3 and 4). Each of these dots can evert itself, or push its head 
out, and wili then be seen by the aid of a glass to be a perfectly de- 
83 


84 


veloped head, having four suckers and a crown of about twenty-eight 
hooks. These heads, when the cysts are fed to dogs, may develop into 
as many individuals. Most of them will generally die, and only a few 
of the stronger will develop. Instead of the single worm which the 
embryo of 7. marginata produces, this peculiar species develops many 
from each of its embryos. In this there is a compensation; for while 
many of the 7. marginata embryos come to maturity, but one or two of 
the cenuri survive, and thus the opportunities for the further perpetu- 
ation of the species are diminished. 

Duration of development.—Experiments have shown that the embryo 
may be found in the brain from two to three weeks after feeding, and 
is then about the size of a mustard seed. Between three and six weeks 
after feeding the worst symptoms of the disease occur. The cenurus 
becomes developed in from two to three months. After this time it 
continues to grow in size and in the number of heads for six or eight 
months, when it usually causes the destruction of the affected sheep. 
When the developed cenurus is fed to a dog it usually produces adult 
tape worms within a month. 

In the migrations of these parasites many are lost and destroyed. Of 
the hundreds of eggs which leave the intestines of dogs few reach the 
stomach of the sheep, and of these still fewer enter the cranium. Of 
the few which become adult—one or two in each sheep affected—but 
a small percentage nowadays arrive in the dog again. Thus of the 
thousands of embryos that left the dog but a single cenurus may return. 
But this cenurus, developing again into several tape-worms, is the 
source of many new embryos for the re-infection of the sheep. 

Disease.—Lambs aud yearling sheep seem to be most liable to infection ; 
those over two years old seem to possess a degree of immunity. Sheep 
herded by dogs; those breeds which eat the grass close to the ground; 
sheep which drink out of ponds or brooks in which the dogs bathe ; 
flocks belonging to careless tlockmasters, Who leave the skulls and vis- 
cera of slaughtered and dead sheep strewn through the pastures, are 
more liable than others. In short, any of the conditions which help in 
the distribution of the parasites render sheep more subject to the 
disease. 

Symptoms and progress.—TYhe symptoms of gid in sheep are depend- 
ent upon the stage of invasion and development at which the parasite 
has arrived. The invasion embraces the period from the time that the 
embryos have been swallowed to the time that they become partially 
developed in the brain. The stage of development embraces the re- 
maining time they pass in the brain. The stage of invasion generally 
passes unnoticed. Between the second and third week those animals 
worst infected—for but few of those infected show signs of disease in 
this stage—show symptoms of inflammation of the brain and surround- 
ing tissues. It is at this period that the little parasites are active in 
progressing through the tissues. Dullness, feebleness, heat in the head, 


85 


intense redness of the mucous membrane of the eyes, and increased 
pulse-beat are characteristics of this stage. The head is generally held 
in a peculiar position, either stretched at length, turned backward, in- 
clined to either side, or drooped. The intensity of these symptoms 
depends on the number of invading parasites. Later, spasmodic con- 
vulsions or paralysis may occur. Death may take place in about six 
or eight days after the first symptoms are noticed. The diagnosis at 
this stage is difficult, but depends on finding the parasites and their 
channeis on the surface of the brain. The former are at this time the 
size of a mustard or flaxseed. A correct diagnosis at this stage will 
influence the future treatment of the flocks. If the sheep live through 
this stage no further symptoms will be noticed for from four to six 
months, when a new set of symptoms will appear. It is said that of all 
infected sheep less than 2 per cent. of those which siow the disease in 
the early stage recover. 

The symptoms of the second stage arise from two causes—from the irri- 
tation produced by the little heads thrust out of the mother bladder 
and from the disturbances created by the pressure caused by the in- 
crease in size of the cenurus. 

The actions from which the disease has derived its common name in 
all countries are especially characteristic. The head turns; the animal 
walks in a circle; it staggers, trembles, has convulsions, acts stupid ; 
it becomes unable to eat or drink, and finally dies of exhaustion or pa- 
ralysis. Thevarious gaitsand peculiar positions assumed by the infeeted 
animals arise from the particular location of the parasite. The length 
of time between the attack and death also depends on this position, 
some parts of the brain being more vital than others. Death oceurs in 
a month or a month and a half after the secondary symptoms appear. 

A diagnosis of the disease in this stage can be determined by an ex- 
amination of an intected animal. Sometimes at this stage the parasite 
softens the wall of the skull by-its continued pressure and the spot ean 
be felt with the fingers. Canurit in the spinal canal are more difficult 
to diaguose. They cause the sheep to stagger and walk peculiarly with 
the posterior extremities. Sometimes the disease is manifested by an 
intense itching along the backbone without any apparent reason. Paral- 
ysis of the hind limbs and of the rectum and bladder often result. 

The gid should not be confounded with the disease caused by grubs 
in the nasal cavities, which sometimes produce similar symptoms. The 
false gid produced by the larvee of the Gistrus ovis will cause more symp- 
toms of a ecatarrh or cold in the head and less of the turning, which is 
so very characteristic of true gid. 

Treatment.—There is no treatment that can be profitably followed for 
sheep thus affected. A veterinarian could in the more advanced cases 
locate the position of the cyst either by inference from the character of 
the symptoms or by feeling the softened spot in the cranium. He 
might, by carefully cutting away or trephining the skull over the point, 


86 


remove the parasite and enable the sheep to recover. The intelligent 
farmer might learn to do this himself, but after it is all done the cost 
of doing it will about equal the value of the sheep saved. The true 
treatment, and that which has saved France and Germany more than 
any medicinal or surgical treatment devised, consists in prevention. 

Prevention lies in the treatment of the sheep and of the dogs. As the 
developed canurus comes only from the craninum or spinal canal, it is 
very easy to prevent dogs from being infected by taking care that they 
can not get these portions of the carcass either when the sheep are 
slaughtered or after they have died in the pasture or sheep-cote. The 
heads should either be rendered, burned, or deeply buried, and not 
thrown into the first convenient corner. 

When the skulls and viscera must be fed to dogs they should be sub- 
jected to a prolonged boiling. The soup so made would be harmless. 
When the lambs are known to have passed through the first stage of 
the disease and are fat enough for sale, at the very beginning of the 
secondary symptoms they should be slaughtered and marketed, care 
being taken with the first killed to verify the diagnosis. This will save. 
more than any other proceeding. The treatment and handiing of the 
dogs are the same as for Tenia marginata, except that T. cenurus, ac- 
cording to Leuckart, develops in three or four weeks, and has to be 
medicinally attended to oftener, or until the dogs are quite free from it. 

The adult.—Tania cenurus, the adult tape-worm, which grows from 
the cyst and causes the gid when in the sheep’s head, resembles 7. mar- 
ginata and also T. serrata, a tape-worm which the dog acquires by eat- 
ing the viscera of rabbits in which the young form is eneysted. 1. ser- 
rata is about as large and long as TZ. marginata. T. cenurus is much 
smaller than either, measuring when mature between 1 and 2 feet,while 
the former measures a yard. It is also a slenderer species. The most 
decided differences lie in the hooks of the head. TT. serrata has the 
largest head, the largest hooks, and the largest suckers, the latter 
being a third larger than those of T. marginata. They are trom thirty- 
eight to forty-eight in number. The hooks of 7. cenurus are between 
twenty-four and thirty-two in number, and the slenderest of the three 
species. The terminal segments also vary, those of 7. cenurus being 
‘the smaller. The total number of joints also differ, 7. marginata having 
five hundred and fifty or six hundred; 7. serrata, three hundred and 
twenty-five or three hundred and fifty, and 7. canurus about two 
hundred. Exact measurements of all these parts as given in text-books 
enable one to definitely determine the species, but the flock-master 
needs most to know that: his own and his neighbor’s dog harbor tape- 
worms, which are prejudicial to his flocks, and to proceed against them. 

The presence of Hydatids (Tenia echinococeus, v. Siebold), (Plate XI, 
Figs. 7, 8, and 9), is, if it oceurs at all in this country, very rare. It 
has a life history similar to 7. marginata, passing from sheep, cattle, 
and pigs to dogs, and from dogs back again. In method of growth it 


87 


differs, forming from a single embryo large masses of cysts, which con- 
tain many individuals capable of becoming adult. Its favorite situa- 
tions in sheep are the liver and lungs. It may occur elsewhere. In 
these places it forms large bladdery masses, whose nature can only be 
definitely determined by the aid of the microscope. As this parasite is 
also dangerous to man the bladders should be handled with care, and 
destroyed. The treatment of dogs is the same as for the other tenia. 

Tenia tenella, Cobbold (Plate XI, Figs. 5 and 6), which causes mut- 
ton measles, is a tape-worm of man, and is supposed to be acquired by 
him while eating mutton through which the cysticercit have scattered. 
The disease has not yet been noticed in this country, and having been 
observed but seldom in Europe, is yet problematical. Mutton af- 
fected would present little white spots as large as flaxseed scattered 
through it. The loin muscles are most apt to be infected. Neither 
this disease nor hydatids can at present be accounted a disease of sheep 
in this country. 


eis 
PQ. 
@. 3. 
oe. 4, 


88 


TANIA Canurvs, Kiich. 


PLATE XI. 


Adult, natural size (Raillet). 

Hooks, enlarged (Raillet). 

Cyst or Cenurus cerebralis, Rud. The white dots are the tienia heads (Raillet). 

Ideal section through two of the dots, showing inverted pouches with heads 
of the tenia developing at the bottom (Raillet). 


Teenia tenella (?), Cobbold. 


5. Section of beef, showing imbedded cysticerci. Mlustrates the appearance of 


infeeted mutton. 


. Enlarged head of cysticerus ovis (T. tenella (2), Cobbold), the sheep measles. 


Reduced from Cobbold. 


Teenia echinococcus, v. Siebold. 


. Adult, natural size indicated by line (Leuckart). 
. Young stages, taken from broad capsule of eyst (Leuckart). 
9. Liver of pig, invaded by echinococcus (Raillet). To illustrate the appearance 


of invaded liver of sheep. 


PLATE Xl 


A Hoen & Co, Lithocaustic, Baltimore. 


CYSTICERCUS OVIS. 
TAENIA ECHINOCOCCUS, 


TAENIA COENURUS. 


ADULT TAPE-WORMS. 


Plates XII to XV. 


The flocks of this country are infested by two species of adult tape- 
worms, remarkably different in form, size, habits, and distribution. 
They are Tenia fimbriata, Diesing, and T. expansa, Rud. Each are 
named from predominant characteristics. 

Neumann states that European sheep harbor more species of adult 
tape-worms than other animals, and enumerates ten species which have 
been described, viz: Tania expansa, Rud; T. alba, Kerr; 7. Benedeni, 
Moniez; 7. aculeata, Kerr; T. ovilla, Rivolta; 7. Giardi, Moniez; T. 
Vogti, Moniez; T. centripunctata, Riv.; T. globipunctata, Riv.; T.ovipune- 
tata, Riv. , 

The majority of these species are apparently new to science, and con- 
sequently uneonfirmed. Some seem to be well founded, while others 
may eventually prove to be re-descriptions of other better established 
species. With the exception of 7. expansa, the writer has as yet found 
no traces of any of them, and it is probable that they do not oceur 
here. 

A description of the tape-worms found here, and the diseases they 
cause, follows. 


THE FIMBRIATE TAPE-WORM. 
TANIA FIMBRIATA, Diesing. 
Plates XII and XIII. 


Tape-worms in Western sheep were noticed by ranchmen in the early 
days of ranching, but did not attract the notice of veterinarians until 
1885~84, when Dr. Faville, of the Colorado State Agricultural College, 
first directed attention to them. (Report Veterinary Department of 
Colorado State Agricultural College, January, 1885.) An earlier epi- 
z0otic, due to tape-worms, had been reported to Mr. Stewart, who, in 
the National Live Stock Journal, for September, 1875, records their pres- 
ence in Missouri sheep, and from specimens at hand determined them 
as Tenia plicatd. As this tenia does not occur in sheep, but in horses, 
it is quite likely that Mr. Stewart saw T. fimbriata. 

In a recent letter to the Department of Agriculture, the late Hon. J. 
M. Givens reiterates an opinion formerly expressed by him in local so- 
cieties of wool-growers, and published by him in Denver (Colo.) papers 

89 


90 


of 1883-84, that these tape-worms were a cause of the larger part of 
the losses among sheep, and urged the necessity of a closer study of the 
subject, in order that more might be learned of the parasite, the amount 
of loss it caused, and the means of preventing it. These losses had 
previously been attributed to a weed called “loco,” which the sheep ate. 
In obedience to instructions received from the Commissioner of A gri- 
culture, the writer proceeded to Colorado in August, 1886, and began a 
study of the various intestinal parasites of sheep. The studies of that 
year were pursued, by invitation, on the ranch of Mrs. Mary L. Givens, 
who, at great inconvenience to herself, did all in her power to aid me. 
In the spring of 1887 | again visited Colorado Springs and prosecuted 
other experiments, which it was hardly possible to conduct in the East. 
Karly in my investigations the fact was recognized that one tenia, 
identified as Tenia jfimbriata, Diesing, was the most abundant; that it 
was scarcely ever absent in sheep examined, and was the probable 
cause of most of the tape-worm disease of Western sheep. As this 
tenia was so constantly present attention was directed to it, and an 
endeavor made to obtain it in all of its stages, and to learn how and 
where it passed its entire life. Another fact was soon learned, that the 
other species of tape-worm (Z'enia expansa), usually abundant in lambs, 
was found so infrequently that it was difficult to find sufficient material 
for study. ‘The methods of study were, first, observation, and, second, 
experimentation. The experiments have, as yet, been productive of 
nothing but negative results. In determining so much of the life his- 
tory as has been learned post-mortem observations have been. the most 
useful. Not only have animals been siaughtered on the ranch for this 
purpose, but advantages offered by inspections of sheep slaughtered at 
the shambles for consumption have been utilized. From these inspec- 
tions the abundance of the parasite, the first appearance in lambs, the 
different stages in growth, ete., could be learned, but it soon came to 
be necessary to study the surroundings of the sheep—the corral, the 
watering places, and the range—to learn under what condition the par- 
asite must exist while external to the sheep, 7. ¢., while passing from 
sheep to sheep. ; 
The effects of the parasite on its host (the sheep) were arrived at 
from studies of the flocks and from observation of individuals at post- 
mortems. The changes found were noted and careful attention paid to 
the point whether certain changes were due to parasites or another dis- 
ease called “loco.” As all of the sheep examined were called * locos,” 
itis evident that there was here a source of error. No certain patho- 
gnomonie lesion of ‘‘ loco” was leafned ; as all of the ** lacos ” were in- 
fected with teenie, the separation of characters due to each disease 
yas difficult. Indeed, it has seemed to me that all of the symptoms 
due to the parasitic disease may be ascribed to “loco.” The characters 
of the tape-worm disease are, however, well marked in lambs which 
have never learned to eat this weed exclusively, and thus could be 


i 


studied without regard to “loco,” which, if a disease at all, belongs to 
yearlings and older sheep. 

Experiments were undertaken with a view of infecting lambs with the 
parasites, while the lambs were kept from other possible sources of in- 
fection; but these were fruitless. Other experiments were entered upon 
with a view of removing these parasites by medicinal remedies. None 
of these were effective in removing the parasites from the gall-ducts, 
and were abandoned until more could be learned of the life history of 
the parasite, when they could again be taken up with perhaps a better 
prospect of success. 

The total results regarding this tenia, so far obtained, are as follows, 
Viz: é 

The parasite persists in an adult stage in the older sheep throughout 
the year. 

The smallest forms appear in lambs soon after the second month of 
their age, and may be found in sheep of any age throughout the year, 
excepting, possibly, the winter months. 

It requires at least six months, possibly ten, to attain an adult size. 

Theovaor embryosare continually passed from thesheep to the ground 
throughout-.the year. The life of the embryo from the time it leaves 
one sheep until it is found in another is yet undiscovered. 

When present in considerable numbers in sheep it determines a dis- 
ease which is not only detrimental to the value of the animal, but at 
times causes the death of large numbers. 

No medicinal remedies can be recommended which will assuredly re- 
move the parasite from the host. 

Many measures may be taken which may prove to be effective in two 
ways, first, in preventing sheep from becoming infected ; second, in 
enabling the sheep to better withstand the ravages of the parasite, and 
thus carry it over the critical stage of its existence. 

The lambs and yearlings are the greatest sufferers, and it is to these 
that the most attention must be paid. 


TANIA FIMBRIATA, Diesing. 


SYNONYMY.—Thysanosoma actinioides, Diesing, 1834. Med. Jahrb. d. desterr. Staat. 

Neue Folge, VII, 105-111. Taf. III (Fig. inverse delin.), Ej. Syst. Helm. I, 
501 in nota. 

Tenia fimbriata, Diesing. Syst. Helm. I, 501. 

Tenia fimbriata, Diesing, 1856. Zwanzig Arten v. Cephalocothyleen, p. 11, 1856. 
Wien. 

Tenia fimbriata, Rept. Dept. Agric., 4th and 5th Annnal Repts. of Bureau Animal 
Industry, 1887, 1888, p. 167, Pls. I and II. 


Tenia fimbriata, Diesing, was first discovered by Natterer, in Brazil, 
in 1824, and published by Dr. K. M. Diesing in 1834, as a new genus, 
Thysanosoma actinioides. Later, in 1856, Dr. Diesing republished this 
parasite as Tenia fimbriata. (See Plate XIII.) 


92 


The first specimens found were detached segments, and from these 
the first description was made. Natterer later found more complete 
specimens and upon these the species was founded. The specimens 
were found in the intestines of the following species of deer, viz: Cer- 
vus paludosus, C. rufus, C. simplicornis, C. Nambi, C. dichotomus. 

A translation of the original Latin description is as follows: 

Arhynchotenia, Rostellam none; mouth unarmed. 

Tenia fimbriata, Diesing. Tab. V, figs. 9-15. (Plate XIII is a copy.) 

Head obtuse tetragonal, large with hemispherical angular bothria; neck none; 
body anteriorly lanceolate, with very short cuneate segments; posterior margin of 
the upper entire, of the following crenate, of the last fimbriate on each side ; the lin- 
ear fimbriwe rounded at the apices. Genital apertures —; length 6’ — 6”; width 
1— 3’. Mature segments, separate, 1’ long, 2’” wide, with lanceolate fimbriz. 

This description was necessarily imperfect, from the lack of abundant 
material, but is nevertheless sufficient to enable us to identify the pres- 
ent species with it. Fortunately, too, excellent figures enable us to 
clearly understand the fimbriate character of the species. At present 
this is the only species known to possess this character. Though char- 
acters founded on form are of doubtful value, until more decided differ- 
ences are determined between the fimbriate tenia of deer and those of 
sheep, this decidedly strong character must serve to keep the two to- 
gether. Besides, there are no strong reasons why the two should be 
separate, for each is of about the same size, a fact which we would 
searcely expect in the same parasite living in hosts of different genera ; 
and each is also found in hosts of similar body temperatures, habits of 
life, and of feeding. That they are found in far-separated localities need 
be no serious objection, for the land connection of North and South 
America would permit of the infection of deer of both continents with 
the same species of parasites. 

Tenia fimbriata is lanceolate when contracted, linear when relaxed. 
It is quite thick, the fimbriw on the contracted specimens presenting 
the appearance of plush. The segments can only be distinguished on 
the more relaxed specimens. Adult specimens are from 15 to 50° in 
length and about 8"™" in width. Immature specimens range from less 
than 5™" upwards. The greatest width is about 2°" from the free end, 
from which point the segments become narrower. There are at the free 
end of adult specimens from three to four or more segments which are 
of nearly equal width, which have lost their contractility and are in the 
process of being shed. The shedding of segments begins in youngest 
specimens and continues throughout the life of the parasite. 

The head or organ of attachment is depressed and tetragonal and 
quite large, sitting on the neck like a pin-head; it is from 1 to 1.6" 
wide, hookless, and has tour very large suckers. The substance of these 
cups forms the greater part of the head. 

The neck cr the part where segmentation begins is very short in con- 
tracted specimens, but can be seen in the relaxed condition. The seg- 


Io 


ments are very short and flat near the head, but concave or cup-like 
toward the free end, each overlapping the succeeding, and all appearing 
linear on the surface of the tenia. The terminal relaxed segments are 
cuneate. The borders of segments nearest the head are slightly wavy 
or crenate. They soon become fimbriate even in youngest tania; so 
that the smallest specimen found demonstrated the fringed character 
of the species. The fimbriz may either be contracted when they are 
stout and short, or relaxed when they are flaccid and proportionately 
longer. They are obtusely pointed. Tne segmentation in contracted 
specimens is made out with difficulty. It is indicated by transverse 
strive. In relaxed specimens it is plainer. 

The sexual organs are symmetrically placed, two sets in each seg- 
ment, each opening in a lateral pore. Each set of organs is composed 
of a male and female portion, or is hermaphroditic. They begin to de- 
velop at some distance from the head and attain maturity towards the 
middle of the tania. 

Besides being remarkable in the fimbriate character of its segments 
this species is also peculiar in the form of its reproductive apparatus. 
The male portion develops first and occupies the whole width of. the 
young segments. It consists of sacs connected by tubules with a large 
tube which finally becomes the much convoluted efferent tube. 

The ovaries develop later, and are situated at each side of the seg- 
ment. They are not shown in the plate. 

The uteri develop last. Each is made of a series of bags arranged 
side by side in a fringe which extends along the top of the segment 
from side to side. These bags open into a larger tube from which they 
receive the developing embryo. The tube connects with the ovaries. 
The embryos develop in the uteri, and probably remain there until the 
segments go to pieces on the ground and thus permit them to be seat- 
tered. They are six-hooked and not essentially different from those of 
other tenia. 

Occurrence.—This tenia is found in the duodenum and gall duets of 
sheep. The former is sometimes found containing from thirty to one 
hundred specimens. More often, however, there are from two to thirty. 
The gall ducts are frequently completely distended by the tenia, which 
pack them so tightly that the parasites can not be withdrawn by pull- 
ing without breaking. Occasionally one, or at the most two, may find 
their way into the pancreatic ducts, which they alsodistend. They get 
into these ducts when young and distend them as they grow larger. 

A few disjointed segments may be found below the duodenum, but 
no entire individuals. Nearly every sheep of a flock will be infected. 

Distribution.—Tenia fimbriata, Diesing, the fringed tape-worm, is at 
present the most common parasite of the sheep of our Western plains, 
and causes by far the greatest ioss of any intestinal parasite in this 
country. 

As may be seen by inspection of the tables showing parasites found 


94 


in different post-mortem observations, it has been identified in sheep 
from Utah, Colorado, and Nebraska. Mr. Codweis, of Granger, Colo., 
a former sheep-owner in New Mexico, says that he has seen them there. 
Mr. Samuel Collins, of Colorado Springs, Colo., who has slaughtered 
sheep from California, Oregon, Utah, Nebraska, and Colorado, says 
that all sheep from these States have them. Dr. Faville personally 
told me that he has seen them from Oregon sheep and from sheep in 
New Mexico. Mr. Stewart’s identification of Tania plicata from Mis- 
souri sheep (National Live Stock Journal, September, 1875) leads me 
to suspect its presence in that State. When to these evidences of 
wide-spread distribution we add those offered by the intermingling of 
Western sheep by parentage and trafiic, and by the opportunities for 
infection presented by the nearly unrestricted communication of the 
ranges, we may believe that this distribution is necessarily wide- 
spread. Its distribution at present is from Oregon and Wyoming south- 
ward and from Nebraska and Missouri westward, or, more accurately, 
from the ninety-fifth degree of west longitude westward and from the 
torty-fifth degree north latitude southward. It coincides with the dis- 
tribution of the sheep in those parts, and more especially with that of 
the descendants of the Mexican or Spanish sheep with which nearly all 
of the larger ranches were originally stocked. The precise limit of its 
Eastern distribution is unknown, but is probably limited to those por- 
tions of Nebraska, Kansas, and Missouri to which Colorado feeders have 
been sent prior to selling them to the Chicago markets. 
_ There are at present no facts at hand to show that the parasite exists 
east of the Mississippi River. In two instances a number were found 
in sheep slaughtered in Washington, D. C., but these animals were said 
to have come from Chicago, Il. 

Life history.—All of the life history of this tenia that is at present 
known has been learned from post-mortem dissections and microscopic 
investigation. 

The adults were found in yearlings and older sheep throughout the 
year. No adults have yet been found in lambs less than ten months 
old. The smallest stages of the immature tenia may be found in all 
young sheep over ten months old, They are usually most abundant 
in lambs, yearlings, and two-year olds. Although a sheep may be in- 
fected with a number of tenie of about the same size, indicating an 
infection covering but little space of time, it is more usual to find the 
parasites of various sizes, indicating a continuous infection. The re- 
tention of food and liquids for some little time in the rumen and reti- 
culum may account for this in part. These varying sizes continue 
from May until December. Sheep examined in May presented various 
sizes and indicated infection in former months. No other datashowing 
infection during winter months were obtained. The smallest tenie 
are found in the duodenum; those found in the gall ducts are larger. 
Tenia less than 2™™ long have been found in the duodenum after the 


95 


gall duct has become completely packed by the parasites. The adult 
worms have embryos in their most distant segments, which are ready 
to be set free. These embryos escape from the host with the feces. 
Until they reappear in the duodenum of another sheep, a quarter of 
an inch in length, their history is unknown. 

A tenia infecting a lamb two months old, the youngest stage noticed, 
is about a half inch long; as the season advances it is joined by others, 
and these increase in size. Four or five months afterward it is found 
to be 4 or 5 inches in length, showing a monthly rate of growth of about 
Linch. From this time it gradually increases in size until the following 
spring, when it becomes adult and capable of furnishing embryos for 
infection of other animals. These embryos escape from the sheep, and 
while many are destroyed a few arrive at their destination in a second 
animal. 

Disease.—The influence that the presence of Tania jimbriata has on 
the life and health of its host is not inconsiderable. The ultimate loss 
is seen when lambs which should be fat and strong are not, and die dur- 
ing the colder weather while the fatter ones survive. This loss, where 
the hosts do not die, can not perhaps be accurately estimated, but is 
nevertheless present, for thin, hide-bound, dwarfed sheep are not 
valuable for mutton, nor ‘do they produce as much wool as they other- 
wise would. 

So slowly are the parasites hatched, so slowly do they grow, and so 
gradually do the symptoms develop, that the teniv are present in con- 
siderable numbers and size before systemic disturbances in the lambs 

_present themselves. An experienced ranchman wil! probably notice 
towards September that some of the lambs are not growing as they 
should. Later in the fall the symptoms increase. In November the 
lambs, which are by this time thoroughly infected with a number of 
strong, tenacious parasites, show the disease quite plainly. 

The disturbances finally shown are induced at first by the local irrita- 
tion produced by the worms attaching themselves to the villi of the 
intestinal walls and causing a greater secretion through their strong 
vermicular action. A continuance and increase of this irritation caused 
by the growth of the parasite and an accession of other parasites, 
finally excites chronic catarrhal inflammation of the duodenum and bil- 
iary duct. To these disturbances we must add those arising in the liver 
from a plugging of the duct by the parasites, which grow so large that 
they distend it to a comparatiyely large size. 

Dr. George C. Faville, in a report of the veterinary department of the 
State Agricultural Coilege of Colorado for 1884, describes the post- 
mortem appearances of these animals as follows: 

Organs of thorax were normal. In the abdominal cavity I found the stomach filled 
with a mass of semi-digested loco leaves. The liver was normal in appearance; gall 
bladder filled with greenish-colored bile. In the duct running fromthe gall bladder 


to the small intestines, I found a mass of tapeworms (Tenia expansa). The small in- 
testine I found filled with a mass of these worms, varying in length from 6 inches to 


J6 


5 or 6 feet. The kidneys were normal in size and color, but upon section, I found 
the pelvis filled with a gelatinous material. The muscular system was exceedingly 
flabby and pale in color, The body seemed to be absolutely destitute of fat. The 
urine was normal, ‘The brain showed a slight serous effusion about the base, and ta 
aslightly greater extent in the region of the medulla oblongata. There also was a 
slight effusion into the abdominal cavity. The only other change that couid be found 
in the brain of these sheep was a slight congestion of the arachnoid membrane. 

The above description is taken from so-called “ locoed ” animals, but 
applies equally weil to tweniz-infected sheep. Of the many * locoed” 
animals examined, but one or two have been free from teni@, and in 
these the gall ducts were thickened and enlarged as though they had 
at some earlier date been infected. Itis extremely difficult to separate 
the symptoms of the two diseases, and it seems to me that many cases 
of *locoed” animals are victims of the tapeworm. That the twnia may 
tend to produce depraved appetites and the morbid craze for a particu- 
lar food, is also a reason for suspecting that the loco disease may depend 
in part on the tapeworm disease. 

In Dr. Faville’s description there is one point which deserves atten- 
tion, and that is the finding of aslight congestion of the arachnoid mem- 
brane. In specimens examined by the writer there seemed to be no 
undue congestion, and the arachnoid membrane, which is a vascular 
one, naturally looks red or dark colored. The brain symptoms of these 
animals are such as arise from anemia rather than hyperemia of the 
brain. 

In affected yearlings which are not suspected of eating loco more 
than other animals (all eat of the loco plants), the following ante and 
post-mortem symptoms can be observed: Lambs that are badly affected 
are large headed, with undersized bodies and hide bound skins. Their 
gait is slightly like that of arheumatic. They seem to have difficulty 
in cropping the shorter grass; they also appear to be more foolish than 
the other sheep, standing oftener to stamp at the sheep-dogs or herder 
than the healthier ones. Others do not seem to see as well, or are so 
affected that they appreciate danger less. In driving they are to be 
found at the rear of the flock. Internally the organs present no marked 
symptoms of disease. The abdomen contains more dark-colored serous 
fluid than normal; the omentum is often nearly devoid of fat. The ca- 
tarrhal inflammation and thickening of the mucous membrane of the 
duodenum and gall-ducts have already been noticed. The liver, in 
cases of long standing, is somewhat smaller than normal; the kidneys 
are sometimes flabbier and paler than normal; the lymphatics look 
somewhat darker; the muscles are thinner and weaker. There is in 
all cases a diminution of fat, and in most cases the leanness of muscle 
is marked. In those places where the fat usually occurs in masses little 
or none is found. Associated with this condition is the presence of se- 
rous infiltration of the connective tissue in the abdomen, thorax, spinal 
and cranial cavities. This infiltration is the most marked in the worst 
cases. The groin, the pelvis of the kidney, the spaces between serous 


Jd 


coats of the abdomen, and other spaces where serous membrane par- 
tially or entirely surrounds an organ are noticeably infiltrated. 

These conditions hold in lambs and older sheep. Between the worst 
affected and entirely healthy individuals there are many grades. The 
symptoms and pathologie lesions are those of mal-nutrition, and aside 
from the lesions of the duodenum and liver are not materially different 
from the systemic lesions caused by other parasites, or from innutri- 
tious food, or from any cause that would prevent the animals obtaining 
and assimilating nourishing food. A variety of other causes would 
produce the same lesions. 

The parasites may produce their evil results as follows: Their vermic- 
ular actions cause increased secretion of the intestine where they are 
lodged, both by direct irritation and sympathetically, @. e., the adjacent 
intestine secretes more than it ordinarily would by acting in sympathy 
with the infected portion. This hypersecretion soon becomes abnormal, 
and the secreting membranes become so changed that they can no 
onger act physiologically. Its best purpose is in furnishing the para- 
site with more nutritious fluid. The plugging of the gall ducts not only 
stops the gall from flowing at proper times, but dams back that which 
is secreted during digestion, and allows it to slowly ooze out after it is 
needed. When the ducts are unobstructed the bladder and ducts are 
lemptied at their proper times, and any interference with this flow 
deranges healthy digestion. The damming back of the gall reacts on 
the secretion in the smaller ducts, and this in its turn reacts on the 
physiological functions of the liver cells. 

The disturbance of digestion due to this impairment of the functions 
of the liver and duodenum has net a merely local effect. In the upper 
parts of the small intestine important digestive changes take place, and 
the disturbance of any of these prevents the proper preparation of food 
for its assimilation through the intestinal wall, resulting in a loss to 
the animal of nutrient material. The duodenum is held to be a very 
irritable organ, diseases in it causing reflex disturbances of various 
kinds. These reflex actions also lead to many systemic disturbances. 
Now these disturbances are each slight, but when combined and con- 
tinued through weeks and months they cause the results just described. 
To one seeing a half dozen or more worms taken from the intestine of a 
sheep the worms do not seem to be a sufficient cause of disease. The dis- 
turbance caused by one worm in man gives rise to even greater systemic 
derangements. The non-assimilation of food and reflex irritation pro- 
dneed by the tape-worms seem to be the chief causes of the impover- 
ished condition of the infected animals. From these causes proceed the 
imperfect nutrition of the various organs and the dropsical effusions 
resulting therefrom. 

From this state of mal-nutrition all of the systemic disturbances can 
result. The staggering gait may arise from the weakened muscular 
system; the absence of fat from non-deposition of more and the con- 

23038 A P f 


98 


sumption of that heretofore deposited; the serous effusions from the 
weakened condition of the system; and the foolish actions from the long- 
continued lack of nourishment of the brain. 

Sheep do not die from the tape-worm disease alone. The greatest 
losses are, the ranchmen say, among the lambs and yearlings. The 
majority may die during cold storms, either from freezing or from sufto- 
cation while piling upon each other for warmth. They may starve to 
death either from inability or lack of desire to eat. They may die from 
other diseases. The tape worm disease appears to render them more 
liable to othez affections and less able to withstand the inclement sea- 
son. It is therefore indirectly chargeable with the loss. Even if the 
infected sheep do not die, the parasite is still a cause of pecuniary 
loss. The impoverished condition traceable to it is a small average 
loss for each animal, but for flocks of over five thousand sheep the ag- 
gregate is thousands of dollars for each ranchman. 

In the article of Dr. Faville, cited above, he quotes a letter * from 
the late Hon. J. M. Givens, whose flocks numbered from six to eight 
thousand head. In this letter Mr. Givens states his loss from dead 
sheep alone for the preceding year at from $3,000 to $4,000. Fortu- 
nately the loss of from four hundred to eieven hundred or more sheep 
does- not occur to flockmasters annually, but such losses are not in- 
frequent, and may be heard of either on this or that ranch during 
different years. Every ranchman knows of and appreciates the steady 
though small loss arising from the depreciated value of his animals, 
due to their ill condition from various causes, and which he strives by 
every means to reduce, for therein lie the profits and success of his 
business. From the study and observation which the writer has been 
able to devote to the tape-worm disease it appears alone responsible for 
more losses than any other sheep disease on the prairies excepting 
scab. The direct death-rate traceable to it is large when compared to 
the entire death-rate, and the indirect loss traceable to it is, though 
more insidious in its character, still larger, for it is ever present and 
ever active. 

Medicinal treatment.—Some experiments looking toward the removal 
of teenie by medicines were made in 1886. Various teniefuges were tried 
with little success. The powdered preparations of pumpkin-seed, 
pomegranate-root bark, koosoo, kamala, male fern, and wormseed proved 
of no avail. 

In order that they might be administered cheaply the proper amount 
of each for ten avimals was mixed with meal, bran, and salt, and fed in 


*The letter referred to gives “loco” as a cause of the losses. Before his death the 
Hon. J. M. Givens had concluded, and communicated to his friends of the El Paso 
Wool Grower’s Association, that the loss of this winter was not due to “loco,” for 
the greatest loss had occurred in young sheep andlambs. The latter had not learned 
to eat “loco” exclusively, were poor, and presented symptoms which he learned 
later belonged to sheep infested with tape-worms. 


99 


atrough. When sufficient meal and salt was mixed with the medicines 
to entice the sheep to eat it, the bulk that contained the requisite dose 
of medicine was too large for a sheep to eat at once. As this bulk was 
retained for some hours in the rumen, the efficacy of the dose was lost, 
for the virtue of nearly all of these remedies depends on the dose passing 
through the intestines in mass. Human patients are usually prepared 
for the medical treatment by abstaining from food for at least twelve 
hours previously; they are then given a cathartic which is followed by 
the anthelmintic. This plan of treatment utterly fails in ruminants, 
for neither stage can be successfully carried out in administering 
these remedies by the mouth. The presence of the large rumen, which 
holds a large quantity of reserve food, and into which new material may 
be taken, accounts in part for this. Some of the food, if sufficiently 
fine, in fasting animals passes directly to the manifolds and fourth or 
true stomach, but a certain proportion would fall into the rumen, and 
thus the efficacy of the total amount acting within a given time would 
be lost. 

These experiments failed, therefore, through the anatomical structure 
of the animal and the method of administration. The presence of 
tenice in the biliary ducts is another reason why tanicfuges can not 
be entirely successful in treatment of sheep with T. fimbriata. Any 
medicine which would affect the tenic in these duets would also affect 
the sheep seriously. It is doubtful whether they can be killed or driven 
from the ducts. The continued or repeated administration of remedies 
that are necessary for expelling these tenia is also an objection to 
their use. The parasites are continually appearing throughout the 
year, and even if those already developed could be driven off, the con- 
stant re-infection would necessitate other operations for their removal. 
The cost of the necessary medical treatment seemed to me to more than 
exceed the good results that possibly might be realized. Further ex- 
periments were therefore delayed until the complete life history of the 
parasite should be determined. In this history we may hope to find 
some stage at which we may more profitably administer remedies. 
Many prescriptions for eradicating tape worms in ruminants are given 
in various journals and agricultural papers. Some of them when tried 
may have proved very efficacious. Unfortunately reports concerning 
the effects of their administration are not recorded. My own experience 
leads me to have little faith in them. There is a feature about them 
which, no doubt, has been recognized by the ranchman who has under- 
‘taken to carry them out to the letter, viz: It is the entire inadequacy 
of the recipes in prescribing methods of administration, and medicines 
of reasonable price as well as of certain efficiency. This oversight is 
of such importance that otherwise good recipes have to be abandoned. 
The Western methods of treating sheep medicinally must differ from the 
Easterp methods, as the methods of sheep-dipping, sheep-shearing, or 
sSheep-husbandry in these sections differ; otherwise the expense of 


. 


100 


treatment will be so considerable that in view of any uncertainty of 
cure few ranchmen will undertake it. 

Preventive treatment.—The most effective service rendered to man 
and beast by the physician has been through tbe prevention of diseases 
and the preservation of health by hygienic measures. Appreciating this, 
and that effective prophylactic treatment of the sheep against infection 
by Tenia jimbriata could not be realized except by the most thorough 
knowledge of the complete life history of the parasite, my attention was 
turned to the investigation of its younger stages and those of other un- 
armed teenie which were available. Such are the difficulties of this in- 
vestigation that the gap in the life history, which may exist between 
the time when the embryo passes from the sheep until it is found, less 
than a quarter of an inch long, in another sheep, has not been completely 
investigated. 

From the present knowledge of the development and life of this par- 
asite there have arisen more difficulties in forming rules of prevention 
than was at first anticipated. ‘The presence of the adult and young par- 
asites throughout the year, and the methods of Western sheep ranching 
are factors which are all-powerful in keeping up the tape-worm disease. 
The case is not a hopeless one, however, for there are certain phases of 
feeding and watering the sheep which can probably be advantageously 
changed, both for the prevention of this and other diseases. 

The feeding occurs on the prairie and in the corral. I would recom- 
mend that the ewes with their lambs should be pastured on a portion 
of the prairie that had not been run over by sheep for some months 
previous. They could be driven to the new pastures about the time 
that the lambs begin to nibble at the grass and drink water. After the 
lambs are weaned they should be changed to fresh uncontaminated . 
pastures until winter, and other older sheep put on the range vacated. 
If there be sufficient range the lambs could be kept on as nearly unin- 
fected ranges as possible until they become two-year olds. In feeding 
lambs on grain and hay measures should be taken to keep the food 
from the ground. The grain should be fed from troughs placed either 
on a board floor that could be cleansed or on ground kept scrupulously 
cleaned of all droppings. The hay should be fed from racks. The 
corrals for the lambs should either be fresh ones or the old ones should 
be periodically and thoroughly seraped out and cleaned. They should 
not be put with a greater number of old sheep than is absolutely nee- 
essary. 

The watering occurs at various places. The usual method is the 
watering at rivulets or ponds. This should be done, but such places 
should be fenced in and troughs provided into which the fresh water 
could run. These troughs should be raised a little above the surface of 
the ground so that they could receive no surface drainage. By the aid 
of pumps and wind-mills this could be easily accomplished. Most water- 
ing places are so situated that by conducting the water through pipes 


101 


or boxes but little expense would be necessary to guide it into troughs. 
These troughs should be kept clean. The lambs should not be allowed 
to drink elsewhere, nor to eat grass in moist places unless it is abso- 
lutely certain that these places are uninfected. The location of corrals 
so that they either surround water or that the drainage is from them to 
the water seems to be a most harmful practice. It not only makes the 
water fouler but renders it more likely to hold parasites. Herders 
should be instrueted neither to feed nor water at the prairie pools. If 
there are places where it is advisable to water they should be prepared 
like the watering places at the corrals. The nearer the ranchman can 
arrive at giving the lambs pure fresh water the less infected with para- 
sites will they become. ‘The salt for the lambs and young sheep should 
be fed from boxes placed near water places and kept constantly full. 
They will take no more than they want and will be all the healthier if 
they have all they need. If they are deprived for a time they may at 
first salting eat more than is good for them. A little eaten daily is 
physiologically better than the larger quantity eaten at intervals. The 
object of feeding the salt at watering places and from boxes is to keep 
them from licking the dirt where salt has stood and to keep them from 
eating the prairie alkali. In addition to the opportunities afforded them 
of being infected with parasites from the salted ground there is the in- 
jurious effect of the swallowed sand. This sand often packs away in 
the gall ducts and produces disease. 

It may be when the gap in the life history of Tania jimbriata is 
known that a single measure of prevention will eradicate it from the 
flocks. Until then the general measures prescribed above are to be 
recommended. 

There are various minor precautionary measures to be fulfilled that 
will help affected sheep to live through the colder winter, and finally 
to render effective service in spite of the parasite. The post-mortem 
examinations have led me to expect that from 80 to 95 per cent. of each 
flock is infected. Now, were all of these to suffer as some of the more 
diseased do, sheep-ranching would be at its end. Fortunately a sheep 
may have a few parasites and not be seriously affected by them. This 
is shown by the fine, large sheep slaughtered which are passably fat and 
yet contain tenie. It is a frequent remark of the ranchman that if 
he could carry his lambs and yearlings through they would do well 
enough afterwards. It is these younger and growing animals that sue- 
cumb soonest to the parasite. It is a rule that all young and growing 
animals are more seriously disturbed by the presence of parasites than 
older ones. Young lambs born in May or June have necessarily but a 
short time in which to grow before the cold season. When food is 
plenty, and there is no disturbance of their digestion, or other ailments, 
they enter winter strong enough to endure the weather without partic- 
ular suffering. Interference with digestion, lack of food, or any ail- 
ments render the lambs so much the weaker, and consequently less able 


102 


to endure the winter storms. The parasites interfere with digestion, 
and to overcome their evil effect means should be taken to supply easily 
digestible and fattening food, which may replace and add to that lost. 
Many ranchmen already feed their lambs extra grain during the fall, 
and have learned that not only are their losses diminished, but that 
the lambs become larger and stronger as well as fatter. 

Formerly the ranchman depended, as many do still, entirely on the 
prairie for grass throughout the season. Of late years many are feed- 
ing more and more hay during the winter, and find that they profit by 
it in the diminished death-rate and the improved condition of the flocks 
in spring. This fall and winter feeding is, then, to be especially recom- 
mended as a remedial measure against losses among tape-worm infested 
sheep. With increased prosperity, flock-masters are adding to their 
shedding at the home corrals. Though the first cost seems considerable, 
such are the evident benefits in preventing losses during the extremely 
cold snaps and blizzards, that not only should they be built at the home 
ranches, but also at the outlying ones where now, with few exceptions, 
none are to be found. ; 

The water afforded sheep, more especially lambs, should, if possible, 
be made warm during the coldest weather. The temperature of sheep 
is about 103° Fah. In giving them water which is less than 35° Fah., 
the heat which is necessary to raise the water to the temperature of the 
animal is withdrawn from other portions of the body, and digestion is 
often disturbed and less water is drank. Experiment has proven that 
animals fatten better on warm water, and were it practicable no water 
cooler than 60° Fah. should be offered to sheep. The maintenance of 
the drinking-water at this temperature for the use of the lambs and 
other home stock would probably repay the Western ranchman, as it 
certainly would the Hastern farmer. This is impracticable at some 
ranches, but there are many home ranches where lambs and blooded 
stock are kept at which the system might be pursued with advantage. 

There is another possible chance of infection which there is no known 
means of remedying. If, as is probably the case, the tenia embryo 
passes with but little modification from sheep to sheep, there is then 
a certain amount of infection that may occur between the ewes and off- 
spring when suckling, the lambs becoming infected with embryo by 
rubbing them from the mother in nosing around while suckling. As 
older sheep have the tenia, and as lambs become infected after being 
weaned, this method of infeetion is only one of many. 

No medicinal remedies or preventives can be advised. The recom- 
mendations above are directed toward lessening the chances of infec- 
tion and preserving the health of the animals. 

It is hoped that the gaps in the life history of Tania fimbriata, or 
others of our unarmed teniw, may yet be filled out. With a knowl- 
edge of this history, the methods of prevention would be evident to all. 

The flock master should take pains to examine the sheep which die and 


103 


inform himself, as nearly as possible, of the cause of death. In ease of 
the presence of tape-worms, causing sickness, he can soon inform him- 
self of their abundance, of the absence of other disease, and of many 
other things. He can soon judge whether others of his flock have them, 
and can more intelligently set about their treatment. <A careful study 
-of each case will then place the observant man in possession of many 
facts which will help him in the proper management of his flock. 

The above recommendations have been written with a view of keep- 
ing the food and drink of the animal as clean as possible. Other pre- 
cautions will suggest themselves to the ranchman. 

Post-mortem examinations. —The tables herewith presented are the 
results of post-mortem examinations of sheep, some of which were killed 
expressly for the purposes ofinvestigation. Others were examined while 
being slaughtered for food, either on ranches or at the shambles in Col- 
orado Springs, Colo., while in other cases examinations were made upon 
dead sheep found either at or in the vicinity of various ranches. From 
the wide-spread distribution of the disease, the notes are such as could 
be taken from nearly all localities, and can not be ascribed as purely 
local causes. Where the observations were taken from the sheep raised 
in States other than Colorado, the State from which they came is given. 

In addition to the presence of Tenia fimbriata, the occurrence of 
Tenia expansa has been noted, aid also of Tania marginata, which 
occurs in sheep in its cysticercal stage. The examinations at the sham- 
bles could not be conducted with the same accuracy while hunting for 
Tenia fimbriata; the occurrence of the cysticerct is, therefore, omitted 
in the post-mortem observations of June 7, 1887, to August 15, 1887, in- 
clusive. 

Table A shows that feni@ occur in sheep throughout the year. It 
also indicates a wide-spread distribution. 


Aes 
: : s | T. fim- Cysti- T. ex- No. 
Date. Bioselegh oc lamps Location. |briata oc-) cerci oc- pansa oe-| of ear- 
=e fe sil Sa ‘ curred in- curred in— curred in-| tags. 
| | 
1886. 
Sept. 16 Th exe eee Colorado.-|.<-.0.-..- 1 
18 1 1 
1 1 
a 1 
2 1) 
9 


Oct. 


en mmr os he io lee eee eam Wee sse none eeerne nel n-n nce 


104 


A.—-Continued. 


ra 2 hey T. fim- Ny sti- T. ex- No. 
Date. ee BuSeP eh 1p | Location. | briata oc-| cerei oc- | pansa oc-| of ear- 
exer ee | eal curred in-\curredin- curredin-| tags. 

INOV A192 scenccetwesisceccies (Sas =cce.cee 1 | Colorado. . 1 1 1 es 

Ss. Sate Seas secta te | Societe ete OS NGO yak P| ee ee Pe eee Ae 

Pe SIE SSS CUES IONS VON saaee sess e Oe 10 hi oa 'ara, ote os eee 

Dee. 32655 eo ea dorees salesse sehen 1 Ss 220 Ove ciknlPaesase 1 1} 105 

2U see tcalevicseasanaties secu ms Sas 11d) seed eee 1 OS eeetsi= et ste 107 

6 UES An SOP ACEOCr | GH ASHnoaeiae fi -2.ddoceee: 1 1 |B a Se 109 

1887. 

AN Soc sesees: clstee asa ace eee ALF) cece Oeste 1 Dis. eke Se 108 

1 a Be ES a ceeeoce Ol Besoeeee sean le 32 Onses 26 Cel ee ASS ae||Baooopaanc: 103-10t 

PA ee Ree Ase Sts 1 c3 1S: Seance BAEC (ote 1 Ae Sees 101 

Apr Oe sc sace ce aaa 1 gl Ray rig era ES Se em 106 

DB whe Sa odd bc de ctoctomtele 1 Teor see u 1 Fl See 1u2 

WIP At ee SaeR das gOraasnd Ssascseate ae 1 ed Oeseee ul 1 eeeseece 110 

SNE! 7 222k caidas soesles Bae SEES Nebraska Qi clk kb ballckia ae sata Ree eee 

Qo a meceeeneniseeee 1H sae semen a eOUe ane LO tuepcemea |e o-toeener | oe 

fe TO eae eee Witalizt:s45 Bi cdewelt Sec |lsenecst 3] Soe 

DOE ac banadacmemisone ae 5 12 | Colorado. 5"). wcfa nora «| /oamerm (cee 

PMY Ose So wcine See ae cece 4 4 EON Fe ee ea es ai lest 

ATID DR So coc e capmatadae cial tameiserceenis ye (0) E Dc kareena ee AN Ue 

Do dociesceceassceces Pha ea coceseern| Is Ape ie POS Rs con sce | | Seow alse cl) meaeietotenes 

RUA Vig ask 540 San winters cone eae eee 1 Bs ie See eee ee eee ees (eeeeerces ats-Secc - - 

oN C0 ti Se er 4 t4 doe. =. Silsenak sel eaae tees | soe 
Total<csct.et22.ce 136 32 139 42 5 


* From June 7 to August 15 inclusive, cysticerct were found in most of the animals examined. 
Tt No tenie found in the two lambs. 
t No teenie found in lambs. 


Experiments— November 30, 1836.—Six lambs, selected froma bunch that had been 
kept in an inclosure since the 15th of October, were, with two yearlings and two two- 
year-old wethers, crated and sent to the United States Veterinary Experimental Sta- 
tion at Washington. The lambs were from a collection of the runts of a large flock 
which had been fed on hay made from prairie grass and on coarse corn-meal and 
bran before November 30. They were watered from tubs, the water being drawn 
from a well and a pond near by. The land on which the hay was grown had not 
been crossed by sheep since spring, at least. The water was clear. The chances of 
infection from these sources were small. The corral where they were kept was a 
good warm shed, located amidst others, with a small adjoining yard. The dogs, of 
which there were two and sometimes more, had free access by jumping the hurdles; 
but I do not remember ever having seen one in the inclosure after the lambs were 
admitted. With these lambs were two old bucks and a few sheep, which were either 
lame or otherwise ailing. They arrived in Washington, D. C., December 4, 1886, 
and were afterwards placed in stalls where they could not be re-infected excepting 
from each other. As Table B shows that there were no adult t@niw@ in the lambs, 
reinfection could only be through the four older sheep confined with them. Rein- 
fection could not possibly have proceeded from some Eastern sheep confined with 
them, for these sheep, when examined, had no T. fimbriata. No dogs were admitted 
to the box-stalls where they were kept. Their food was Eastern clover and mixed 
corn and bran. They were furnished with well-water and salt. The adults were 
numbered 101 to 104; the lambs from 105 to 110. 

December 9.—Two Eastern lambs, Nos. 111 and 112, were put in the pen with Nos. 
101 to 110 inclusive. Nos. 111 to 118 were a number of Eastern coarse-wooled sheep, 
bought for experimental purposes. 


December 13.—Nos. 111 and 113 were found to pass mature embryo bearing proglot- 
tides of 7. expansa. 


105 


December 17.—Fed Nos. 105, 107, and 109 with proglottides of 7. expansa from Nos. 
111 and 113. 

December 31.—Lambs Nos. 106, 108, and 110 were put in a pen with Nos. 111, 112, 
113, and 115. And sheep Nos. 101 and 104 were put with Nos. 114, 116, 117, and 118. 
Later on some other changes were made, but as the Eastern sheep were found to con- 
tain no taniw when examined, these changes had no result, and could not have 
affected the result in other ways. 


The object of arranging and re-arranging these sheep was to give 
possible chances of infection to the uninfected sheep. 

Table B is compiled from data obtained from lambs born in 1886; 
from four wethers, which, with six of the lambs, were removed to the 
experimental station in Washington, D. C., and from a few lambs 
born in 1887. The sheep marked M, killed June 25, was also adult. 

Table B shows that the Tania jfimbriata begins to appear in two or 
two and a half months old lambs, that they continue throughout the 
winter and gradually attain maturity as spring approaches. Each of 
the tables, A-and B, shows that adult tape-worms were to be found 
throughout the year. 


B. 


Time in weeks. 
Number 2 
No. of serra ; es Age in | 
Mab Length of 7. fimbriata. nae eae im 
2 Wash- 


ington. 


Date. 
From 
range. 


OOS OO sR Somat O ame Siem wera 


LOM) Mamtyr= sa cys Ole ans — aioe = 45 24 17 
MI SARCE SaRerc PESTO OEM Reo steieie cin sim 49 27] 20 
TOD Ploa eo Immature..........-- 50 28 21 
104 Spee eas eee OU sac we ce nccneces 50 28 21 


June 25 


*The age is that of the lambs and is estimated May 15. 


Nos. 101 to 104 and M were adult sheep; all others were lambs. 
Adult tenie contained embryo. 
Post-mortem examinations— December 26.—No. 105 died. It contained four small 


Tenia fimbriata, the largest about 2 long, and fifteen cysticercit of T. marginata, each 
less than 1°™ in longest diameter. 


106 


December 29.—Killed No. 107. It contained nineteen small 7. fimbriata, the largest 
about 4°" in length, and twenty cysticerci, the largest a little over 1°™ in diameter. 

December 30.—Killed No. 109. It contained over one hundred small tenia, ranging 
from 5™™ to 10° in length; also a few small cysticerci, apparently of same age as in 
107. 

January 8.—No. 108 died. It contained three specimens of Tria expansa ; one of 
these was adult ; many small 7. fimbriata, varying 1°™ to 7™ long; also six cysticerci, 
somewhat larger than the earlier found. 

April 20.—Killed No. 106. It contained many T. fimbriata, over twenty-five in all, 
which were over 7° in length; none were smaller. The duodenum and gall ducts 
were packed. None were adult. / 

May 7.—Killed No, 110. It contained one adult 7. fimbriata and several cysticerci. 

March 14.—Killed No. 103. It contained from fifty to sixty tania from 7@™ to 10°™ in 
ength; four of these were in the gall ducts and were among the largest in size. Te- 
nie immature fo adult. 

March 29.—Killed No. 101. Found tenie in duodenum, gall ducts, and pancreatic 
ducts. The gall ducts were engorged; the liver smaller than normal. The tenie 
ranged in size from 7°™ to 14°"; three were adult. There were three cysticerci. 

April 23.—Killed Ne. 104. Found five tenia from 2™ to 4e™ in length, but no eysti- 
cerct. 5 

April 28.—Killed No. 102. Found fifteen teniw. The largest were not over 7™ in 
length, and immature. There were two esyticerci. 

Table C is made up from data obtained from the six lambs, Nos. 
105 to 110, inclusive, transported from the prairies to Washington. It 
shows the comparatively slow growth of the parasite; also the abun- 
dant infection of some of the animals so long as they were exposed to 
infection. It also presents either the possibility of infection after they 
were taken from the prairie or the retention of the embryo in the ramen 
through aconsiderable time. 


. 


C. 
| 

No. of Weeks | Weeks | Weeks 

Agein} Tania Teenie after | after | after 
Date. No. | weeks. | fimbri- size. October Decem- | Decem- 

ata. 15. ber 1. | ber 31. 

Centimeter. 

Deer 26 2e—-. 6 OSSD ASNISD SOD Oa oO eae 105 PAN ee: CSch Dee aear cee 10 Ce Res 3c 
20 naa nina cnissinie see viaeessad cians seaice 107 onl MLO beret Lear cterare 11 Ae eee 

BOM sa: eet ote wee cieae eee ben comes 109 | - 33} 100+..| 0.5-10..... 11 4-f- || nooner 
Sans 1B) cee aticweneceeaccck cadens sete acces 108 SE Sp IM yong lan ees 2 6 1 
Ape: 20 screened samt ee sanaceeeee coaceess 106 491025 ase. 1D cates 27 20 16 
MAY, . Waitspinwncwecaecaensieclsaestcaeuecas 110 Bik) isk eae | Adult. .... 29 23 18 


vores a ee == 


October 15, the date on which the lambs were taken from the prairie and corralled. 
December 1, the date on which the lambs were received in Washington. 
December 31, the date on which the adults, Nos. 101 to 104, were removed. 


Lambs K and I, Table B, show that the tenia was developed to a 
length of 2° in less than ten or twelve weeks, for the number of tani 
found shows a slight infection and some time may have elapsed after 
the birth of the lamb before its infection. 

Lambs A to I, Table B, show that in from twenty-three to twenty- 
eight weeks the tenia may develop to 8 or 10° in length, and that the 


107 


infection is proportional to the time exposed. The infection is, how- 
ever, a variable quantity, and no definite statements can be deduced. 

As the lambs do not begin to nibble grass and drink water until some 
few days after their birth, the development of tenia in K and L prob- 
ably required not over two months. Lamb A, examined October 21, 
about twenty-three weeks after birth, gives, when compared with K 
and L, an approximate rate of growth of the tenia of 2° a month, 
more or less. The rate of growth must so vary at different times that 
no definite rate can be determined at present. 

The teenie of No. 105, one of the same lot of lambs as the foregoing, 
were no larger after thirty-two weeks than those of K and L after ten 
weeks. This points to a recent infection of No. 105, 7. e., within ten 
weeks, or about the time the lambs were taken off the prairie and re- 
ceived into the corral. The teniw of Nos. 107, 109, 108, and 106 coin- 
cide with this; but the lambs No. 109 and 108 also point to a later in- 
fection, aS many very small tenic were found in them. No. 108, which 
had teenie 1° long six weeks after its receipt in Washington, would 
lead us to suspect a recent infection; but this is not necessarily the 
ease, as the influence of the rumen of the sheep in detaining the para- 
-site for a length of time has yet to be learned. The absence of young 
tenie measuring less than 7° in No. 106 at sixteen weeks after its 
last association with an animal containing adult teniw and twenty 
weeks after its arrival in Washington is also of interest in that it points 
to infection of the lamb from the adult sheep associated with it. No. 
110 shows avery slight infection, and one, judging from the age of 
teenie, that could have occurred in Colorado. 

The six cases show a slow growth of the parasite; they a!so point to 
one of two things: That the teniw are, as embryos, retained in the 
rumen for some time after being swallowed, or that these teniw are 
continually infecting their hosts by the direct method; that is, the 
embryos passed by sheep, with little or no preparation, pass into other 
sheep and develop witbont the intervention of an intermediary host. 
So far nothing has been found to absolutely prove or disprove the latter 
statement. The infection, as shown by the various sizes found in these 
lambs and other sheep, points to a continuous infection nearly all the 
year. (See Tables A, B, and C.) 

Nos. 106 and 110 indicate a cessation of the infection for the length 
of time it required the smallest (7°™) to attain their size. Lamb A in- 
dicates the time to be something less than twenty weeks, or at the 
period when they were received at Washington. Nos. 106, 107, 108, and 
109, which had been confined eleven and twelve weeks, show as great 
infection as has been seen. This would happen with animals which 
were being infected in confinement, for the opportunities of infection, 
if the infection should prove to be direct, are greater. Various condi- 
tions, as the weather, food, water, etc., have so much to do with the 
problem of infection that far more data are necessary. 


108 


The fact of slow development and continuous infeetion are the main 
points brought out in this experiment. Continuous infeetion is natu- 
rally one of the results where tenic are constantly developing and 
shedding ripe proglottides laden with embryos for the infection of other 
hosts. Continuous infection also leads me to suspect that no interme- 
diary host is necessary for the contiiuanee of the life of the embryo. 
This proceeds from the fact that no single species of mollusk, insect, or 
other animal is to be found at all seasons and places necessary to suit 
all the conditions under which we find the host infeeted. 

Experiment No, 2.—A lamb dropped at a slaughter-house in this city was kept with 
its mother in an uninfected stall. 

The lumb was fed on January 10, 1887, with a large quantity of proglottides of 
Tenia expansa from No. 108. The embryos were found to be alive and moving before 
feeding. 

On March 20 the same lamb was fed with proglottides of T. fimbriata from No. 103. 
These contained live embryos on the 18th instant. 

On Mareh 29 fed the same lamb with proglottides containing embryos of 7. fimbriata 
from No. 101. 

On April 19 this lamb was killed and nothing was found except afew white spots 
in and on the liver. The experiment bad no results. 


AN EXPERIMENT TO INFECT LAMBS WITH TAINIA FIMBRIATA. 


Experiment No. 3.—May 23, 1837, placed fifteen ewes with nnborn lambs in three 
box-stalls. They were fed on alfalfa, hay, corn, and bran. Their water was drawn 
from a hydrant near by. The ewes being thin in flesh, and taken from the prairie 


grass and placed upon dry feed, thrived but poorly. Between May 23 and May 29 — 


eleven lambs were born, which lived until the close of the experiment. Five of the 
largest and oldest were placed with their mothers in stall No.1. The remaining were 
divided between two stalls, Nos. 2 and 3. 

These animals were removed from all sources of infection through 
food and water, and the lambs had never been exposed to any source 
of infection. The ewes were suspected of being infected with 7. fim- 
briata. If the lambs became infected they would either take them of 
their mothers or from their feed. Between May 26 and June 15 the 
lambs were fed in stall A several times each with a number of ripe 
proglottides from adult teniew. An interval was left between each 
feeding, and each lamb was fed at least three times. The other lambs 
were not fed. All but two of the ewes were found to contain adult 
tenwe when examined later. 


The lambs and ewes were killed in nearly equal lots on June 25, July 
15, and August 1. 


June 25, killed one ewe and one lamb from pen No. 1, two ewes and one lamb from 
No, 2, and three dry ewes from No. 3. Lambs uninfected. One ewe had tenia 2°™ 
long. 

July 15, killed two ewes and two lambs from No. 1, two ewes and two lambs from 
No. 2. Lambs uninfected. 

August 1, killed two ewes and two lambs from No. 1, and two ewes and two lambs 
from No. 2. Lambs uninfected. 


109 


The lambs were kept for two months, and were not infected in this 
time. This experiment shows that either a longer time is necessary for 
jufection or that the embryo has to undergo some development or prep- 
aration that was not allowed and of which we are ignorant. The speci- 
mens fed were taken from slaughtered sheep, examined with a micro- 
scope, and fed by placing the proglottides which contained living 
embryos in the lambs’ mouths and waiting until they had been swal- 


lowed. 
The lambs while living with their infected mothers should have been 


infected, providing infection by embryos fresh from the host be possible. 
As this was not the case, further preparation and development of the 
embryos outside of the ovine host seems necessary, 


Fig. 


Fig. 
Fig. 
Fig. 


110 


TANIA FIMBRIATA, Diesing. 
PLATE XII. 


1. Adult, natural size. From contracted alcoholic specimen. 
2. Head, edge view, X6. 
3. Head, side view, X6. 
4. Head, top view, x6. 
5. Portion of segment: a, genital pore; b, cirrhus pouch; ce, seminal appara- 
tus; d, the efferent tube; e, the rudimentary uterine apparatus; f, vagina; 
g, the receptacle of the semen; h, fimbrize. 
6. Portion of segment.more mature than Fig. 5: a, genital pore; b, cirrhus 
pouch; d, efferent tube; e, the uteri. 
7. The uteri enlarged. 
7a. The uteri still further enlarged, showing the contained embryo. 
8. A half-grown tienia, showing the fimbriw, x2. 
9. Fragment of tenia from near head, showing the lateral excretory vessels. 
10. Terminal portion of adult, 2: a, segments which have lost their contractil- 
ity; b, separated segments. 
11. External reproductive apparatus, X40: a, genital pore; b, cirrhus pouch; c, 
penis. 
12. Adult segment showing the symmetrical arrangement of the reproductive 
apparatus: a, a, genital pores; b, b, uteri; ec, ¢, fimbrize. 
13. Embryos as they exist in the uteri: a, a, envelopes; 6, b, embryo. 
14. Embryo showing envelope and its six hooks. 
15. Youngest tenia found. Natural length indicated by lines at their sides. 


All specimens except figures from 1 to4 and 15 were drawn from fresh preparations. 


PLATE XII 


ra 


“eng 
re 


ATA AEA Nana. 


mPa : 


Hiveean 
= 


a 


nN 
ANT 
pin 
AWTS 
aan 10 
SMITE 


pan a Al 


SS tsa 


“iy 


2a 


MVADAAAAAAIIOEARDAAIARAL 


TAENIA FIMBRIATA, 
(The Fimbriate Tapeworm.) 


8 
ET 


Bray 
a= 


re 
(33 


A.Hoern & Co, Lith, Baltinnore, 


112 


TANIA FIMBRIATA, Diesing. 


PLATE XIIJ.—Diesing’s original figures. 


Fig. 1. Adult, natural size. 
Fig. 2. Head, side view. 
Fig. 3. Head, top view. 
Fig. 4. Segments near head. 

Fiz. 5. Segments further removed from head. 
Fig. 6. Some still more remote. 

Fig, 7. From near end, 


PLATE XII 


CUE? 


ul 


NAMA ALLY AI 


‘ 
7 
PW 


A.Hoen & Co. Lith. Baltinore. 


Geo. Marx, del. 
TAENIA FIMBRIATA. 


THE BROAD TAPE-WORM OF SHEEP. 


TANIA EXPANSA, Rud. 
Plates XIV and XV. 


Tenia expansa, the Broad Tape-worm, is one of the best known of the 
internal parasites of sheep, because of its flatness, length, and large 
size. In summer and fall it is quite abundant. The amount of pecun- 
iary losses occasioned by its ravages depend upon the season and its 
abundance in affected flocks. It was introduced into tiiis country from 
Europe along with the imported flocks which harbored it. Sinee then 
it has been parasitical on our flocks from generation to generation. It 
is now distributed from the wooded hillsides of New England to the 
grazing lands of Georgia, over the fertile prairies of Ohio, Illinois, Lowa, 
and Nebraska, and the boundless prairies, basins, and mesas of Colorado, 
Utah, California, and Oregon; in short, over every sheep-grazing local- 
ity in the United States. Reported outbreaks from this vast extent of 
country are comparatively few and scattered, but are sufficient to warn 
us that when the pastures become narrowed, older, and overstocked, we 
may expect the same trouble with this and other parasites as has been 
experienced by sheep raisers through all time in the more densely pop- 
ulated districts of other countries. 

Description —The entire worm measures in length about 5 yards, and 
in width from one-twenty-fifth of an inch at the head to a half or three- 
quarters of an inch at the tail. Its thickness is from one-tenth to one- 
twelfth of an inch. These dimensions vary greatly, depending on the 
contracted condition of the worm when measured and on its state of pre- 
servation. Adult specimens taken from sheep may average less than 4 
yards, or may slightly exceed 5; but they never, in this country at least, 
attain that gigantic measurement of 100 feet ascribed to them by Eu- 
ropean observers. The head is somewhat larger than the neck, and 
measures one-twenty-fifth of an inch in width. It is smooth on the end 
and has its four suckers directed anteriorly. Its neck, or that portion of 
the worm immediately succeeding the head, which is unsegmented, is 
shortor lacking. The body of the worm is apparently made up of a series 
of very short but extremely wide joints, which vary in length and width 
in the successive portions of the body. The first rings of the tenia are 
very short and narrow; the others are longer, but are always broader 
than long. Those segments which are about two thirds the entire length 


23038 A P——8 413 


114 


from the head are the longest. From these to the end they become grad- 
ually shorter and wider. In width the segments gradually increase from 
the head to theend. When first collected the texture of the worms is 
usually opaque and white, and it is only by allowing them to stand in 
water that they become transparent enough for study. It can then be 
seen that each segment is bilaterally symmetrical—that in each half is 
an independent set of genital organs. These become apparent ata little 
distance from the head, but qelad in their best development about half 
the entirelength from the head. From this point on the segments be- 
come more and more epaque tothe end. The genital organs first appear 
as alittle horizontal line on each side; gradually a little rosette grows at 
the end of each line; these dacmeas and the segment becomes filled 
with the young eggs or embryos, which form the opaque mass. ‘The ex- 
ternal genitals consist of around pore on either side of each segment, in 
which is a minute dot, the opening of the vagina, and an exserted in- 
tromittent organ. The apparatus is called hermaphroditic, 7. e., each 
half of the segment is capable of fertilizing itself; but it is likely that 
cross fertilization also occurs. Fertilization occurs about where the 
dots which line each side of the worm appear plainest. Irom this 
point on the eggs are developed into embryos until the end of the worm 
is reached, when the segments are prepared to retain vitality as indi- 
viduals for some time after being ejected with excreta to the ground or 
water. 

Besides the reproductive apparatus there are two so-called excretory 
canals, one on each side of the worm, running the entire length. I 
have not observed cross-canals, such as occur in the armed tunic, as in 
T. marginata. 

There is no alimentary canal. The nervous system is very rudiment- 
ary, consisting of little more than bundles of nerve fibers. The suck- 
ers are each supplied with their special fibers, connected together, and 
2ach segmentis supplied b« two long nerve bundles which run parallel 
to the excretory vessels on either side. Absorption of nutrient material 
or feeding takes place through the surface of the segments. 

The young eggs or embryos are polyhedral by pressure, and measure 
about 0.05 to 0.07"™ in diameter. They have usually two envelopes, 
between which a considerable amount of oily material is held. They 
may have three such. Around the embryo is a pear-shaped apparatus 
whose small end is surmounted by a cap with shredded periphery. The 
embryo itself is contained in a cavity in the large end of the pyriform 
covering, and when alive can be seen moving around init. The em- 
bryo seems to bea highly refrangent mass of protoplasm provided with 
six hooks, and does not look essentially different from the embryos of 
other tape-worms. The cap with shredded edges is the remnant of a 
mass which originally included and covered the embryo and its balloon- 
like expansion. No attempt has been made by the writer to work out 
its earlier embryology. 


115 


The next stage of the embryonic tenia found was taken from a lamb. 
In this stage the young worm (about ?"™ long) is well outlined. Ithad 
a head with four suckers and a short unsegmented body. The next step 
in the development showed the body segmented. In one or two speci- 
mens I have seen a little loop with its convex end projecting towards 
the outside, but have not yet been able to determine its significance. 
Between these stages and the adult the different steps of development 
are easily filled in by a study of a single worm, 

Occurrence and distribution—Although there is a periodicity in the 
appearance of the broad tape-worms among lambs, causing at times epi- 
zootic outbreaks, the worm may be found throughout all months of the 
year in localities where it occurs. No section of the United States 
seems to be entirely free from it. They have been found in winter, in 
spring, in summer, and in the fall, in the intestines of lambs examined 
at the abattoir. They are not so frequent in winter and early spring as 
at other times, but seem to be more abundant in some localities than in 
others, though this may be due to unequal opportunities of observation 
in all places. A less number was found in the West than occur in the 
_ Kast. Conditions of climate and soil also seem to have some influence 
on the appearance of the tape-worms. Damp, warm climates and 
heavy, moist soils appear to be more favorable to their preservatiou 
while on the ground. But none of these factors would seem so favora- 
ble to the growth and life of the tenia as holding the sheep on over-fed 
pastures, as demonstrated by experiments elsewhere related. 

Differential description.—Tenia expansa differs from T. fimbriata in 
the method of shedding its segments. Instead of maturing a few of 
the segments at a time and shedding them, as the latter do, whole sec- 
tions ripen and pass away, so that an examination of a sheep which 
has been observed to pass proglottides during a past week will reveal 
but little more than the head of aworm. The exact length of time that 
is consumed by the worm in maturing, so that it all passes away, is 
undetermined, but it is nevertheless an important factor in the disease, 
for after the worm is passed the lambs begin to recover. From what 
was learned and seen of the disease the opinion was formed that the 
worms do not retain their adult size more than a month. The heads, 
which are left, develop slowly and form new adults. They may not 
cause so much disturbance at this time, however, for the lamb becomes 
older and better able to withstand them. 

The rate of growth of the broad tape-worm is very rapid as compared 
with that of Tenia fimbriata. This is easily demonstrated by the fact that 
T. expansa are found 2 to 5 yards long in lambs from two to four months 
old, while 7. fimbriata are scarcely. as many inches long in lambs of the 
Same age. If we suppose the lamb to become infected during the first 
month of its life, the age of the twnia in the above lambs would not be 
over three months, which would give an average growth of nearly a 
yard per month. This enormous increase in size is an important factor 


116 


in rapidly developing disease in the young lambs. The Tonia jfimbri- 
ata, on the contrary, slowly develops a disease which culminates in 
older lambs. 

Life history.—The life history of Tania expansa is only incomplete 
in that portion of its life which it passes outside of the host. Just 
exactly what happens to the embryo-containing egg, between the time 
that it escapes until it is again found in sheep as a little head with 
four suckers and a short tail-like appendage is not known, but from our 
present knowledge may be inferred with a tolerable degree of accuracy. 

No one has yet been able to either develop these embryos in water 
or to feed them and produce an infection in sheep, So it has been sup- 
posed by reasoning from the life history of other forms of tenia, that 
these embryos must pass a portion of their development in some of 
the minute animals which inhabit the grass and water of sheep farms, 
From my own Studies, although I have not yet been able to produce 
tape-worm disease by feeding the embryos, I think that the above view is 
fallacious, and that these embryos need not pass any of their existence in 
other invertebrates. Dr. F. A. Ziirn (Die Schmarotzer, p. 191, 1882) is 
authority for the statement that ‘ the disease is also present in sheep 
which have been fed entirely in the stalls, though more especially 
among the younger and youngest of a herd which are sent to the 
pastures.” , 

Hxperiment to demonstrate method of infection.—About the middle of 
May, 1888, six lambs, from three to four months old, were bought on 
the market and added to the flock at the Experimental Station of the 
Bureau. This flock was kept in a small stable with an adjoining hill- 
side yard. They were fed on clover and grain from the market, and the 
water was drawn froma well near at hand. The vard was sufficiently 
large to be grassy, but they soon ate it down to the roots. In one cor- 
ner of an adjacent pen was an iron trough, kept full of water. After 
a rain the water might have stood in the yard for a day or two ina 
small puddle, but there was no so-called permanently standing water 
which could have harbored insect life. There were already on the 
place three lambs, with their mothers, which had been raised there that 
season. 

May 16.—Two lambs were fed by drenching with the embryos or eggs of Tania ex- 
pansa. 

May 22.—An iron trough was prepared with a grass bottom, and then filled with 
water. A quantity of segments of T. expansa were scattered in it, and at first only 
two of the lambs were allowed access to it. Afterwards, all were allowed to go and 
drink out of it. 

June 11.—Slaughtered one of the lambs, which had been drenched with 7. expansa 
embryos May 16, and had since been held in the yard with the trough prepared on 
May 22. No deniw were found. The experiment was therefore of negative value. 

After these dates the lambs were neglected, so far as feeding experi- 
inents were concerned, until fall. 

June 21.—One of the experimental lambs, which had previously been fed with ripe 
segments of 7. ecpansa, was killed. It was in poor condition, No tenia were found 


gb Ili7) 


in it, but numerous sears of T. marginala furrows on the surface of the liver. It was 
also found that numerous white patches, which were scattered along the mucous 
coat cf the small intestine, were due to a species of coccidia. As the latter disease 
has not been seen since that time, and as there was a possibility that the lamb had be- 
come infected with the coccidia from the dirt thrown out of neighboring rabbit pens, 
where the disease was abundant, it has not gince been studied. The results, so far as 
T. expansa is concerned, were negative. 

October 10.—A ewe lamb was examined which had died some hours previously ; but 
one cysticercus was found. 

October 13.—A young buck lamb was examined, which was bought in May with his 
mother, soon after birth, from a neighboring slaughter house and was one of those 
which is referred to as raised on the place). There were found a quantity of young 
teniae, many adult and young of Strongylus contortus, a few young Dochmius, and a 
few Trichocephalus. ‘This lamb was one of the two that was drenched with eggs on 
May 16. He had pastured with the others, which it was subsequently learned had 
adult tenia, and which had been purchased supposing them to be infected. 

October 9.—A buck lamb was examined, one of the six purchased in May. Old 
cicatrices of Tenia marginata were found in the liver, six Cysticerci of this species, 
two adult and six young Tenia expansa, a quantity of young and old Strongylus con- 
tortus, and a few specimens of Trichecephalus. 

October 16.—A buck lamb, another of the six, was found to be infested by a quantity 
of very young tenia, also by young and old Strongylus contortus, Dochmius, and Tri- 
chocephalus. 

October 17.—Another of the six animals bought in May was found to contain young 
and adult Tenia expansa, Strongylus contortus, Dochmius, and Trichocephalus. 

January 3, 1889.—A lam» slaughtered for examination was found to contain three 
Tenia expansa, one Cysticercus, and many specimens of Strongylus filicollis. 


The period which had elapsed from the time that these lambs had been 
received on the place, to the period when the majority were examined 
(from May to October), was about five months. Those first killed gave 
negative results, probably because they were examined too soon after 
feeding. ‘The lot examined in October gave very positive results. 
The worms found in them varied from very young to adult. The smail- 
est and youngest are those shown on Plate XV, figs. 8,9,and 10. These 
were not fed to the sheep, for lambs which had not been fed were in- 
fected ; but the majority of the young tape-worms were acquired and 
developed after the sheep came under the experiment. This is amply 
proven in the case of the young buck bought and put with its mother in 
the experimental yard before the former was two days old. That the 
time of development of the adult worm is less than four months was also 
proven, from the fact that other lambs, less than four months old, ex- 
amined in May at the slaughter house, contained aduit tape-worms. 
The lambs, therefore, acquired those parasites on the place. The ques- 
tion of the necessity of an intermediary host is also settled by this ex- 
periment, for none of those invertebrates, which are usually suggested 
as being the intermediary bearer, were present at any time; nor were 
the conditions which are essential to the life of many such invertebrate 
hosts present. The pasture was and is a very dry hillside yard, from 
which the grass was eaten very close by the sheep. 

There is another phase of the question which is stillin doubt. Early 


118 


in the experiment segments of tape-worms were placed in an iron trough 
out of which the sheep drank, or could have drunk all summer long; 
and there might have been times when, for a day or two, alittle puddle 
of water could have collected after a rain. In these, more especially 
the former, the development of ,the parasites could have proceeded 
until they were taken up by the lambs. The point in doubt is, whether 
the lambs got their embryos from the water or from the yard while 
grazing. Lam inclined to believe the latter, for they acquired other 
species of worms which were not placed in the iron tank, and these were _ 
also in various stages of development. Still another feature inclines 
me to this view. If the lambs had been infected from the iron tank 
they would very likely have been infected by a large number of tenia, 
all of nearly equal size; but they were not. Direct infection has been 
tried before, but only negative evidence obtained.’ The failures prob- 
ably arose not only from expecting results too soon, but also from not 
preparing the infecting material properly. 

Since writing the above, two lambs have been examined, which give 
additional data : 

August 10, 1889.—A five months old lamb was examined, which had been born at 
the experimental station, and kept there under the same conditions as the other 
lambs, i. e., water supplied from a pump and pasturage from the yard and lane near 
the sheep pens. This lamb contained two adult Teniae, and Strongylus contortus,-S. 
filicollis, S. ventricosus, Dochmius cernuus, Trichocephalus affinis, and Uesophagostoma 
Columbianum, in all stages of growth. The last species did not show adults, 


A 


August 10.—Examined a lamb eleven weeks old, which had been bought with its 
mother from a neighboring slaughter house when-two days old. The lamb had been 
kept under the same conditions as above. There were found one adult Tenia (shed- 
ding proglottides carrying well-developed six-hooked embryos) and all the other 
species enumerated above, but not in the same abundance. Each of these lambs 
showed that the infection had been continuous. The elder of the two yielded a 
greater number of S. filicollis than any sheep hitherto killed, and led me to think 
that this species may have been productive of more trouble than had hitherto been 
suspected, 

The above experimen ts were planned with an aim to obtain infection 
within a limited area, and under conditions which could be controlled, 
deeming it better to obtain infection under such conditions, though 
there be a number of them to complicate the question, than to restrict 
the conditions and not get an infection. 

The presence of the adult tenia in the comparatively young lamb of 
eleven weeks shortens the limit of time of complete development of the 
tenia, The tenia was about two yards long, and had developed inside 
of three months. A reason for the early infection of this lamb was that 
its mother died and left it to shift for itself. These experiments con- 
clude the series for determining whether sheep necessarily get the worms 
from drinking water or from the pasturage. 

Summary.—The life history seems from the above to be a compara- 
tively simple affair. The embryos pass from sheep to sheep and develop 
into adults, which reproduce young for infection of other animals. 


119 


Whatever changes the embryos may pass through outside the sheep 
can have little to do with the case as far as a knowledge of prevention 
of infection goes, for but very few of the conditions under which these 
sheep were kept can be improved by the flock-master. 

Disease.—The tape-worm disease can be diagnosed by finding the lit- 
tle white oblong tape-worm segments which are voided from the sheep 
and stick to the moist pellets of dung. They may also be found adher- 
ing to the wool and dirt around the tail. But this is only after the 
tape-worms have become adult and have begun to shed segments. 
Though sheep often harbor tape-worms and give no evidence of their 
presence until after slaughter, there are other cases in which their pres- 
ence is only too evident to the flock-master. The first indications of 
the disease are usually unobserved, because of the glow growth and of 
the comparatively small number of parasites that may be developing. 
The time of growth occupies about two or three months from infection. 
The number of individuals may be from two or three to a hundred, but it 
is unusual to find more than a half dozen adults together. As many as 
fourteen adults were found in a lamb four months old. When young 
they occupy but small space, need little food, and cause few vermicular 
contractions. In the sarlier stages it is plain that they cause but little 
trouble, but when they grow so large that they seem to fill the whole of 
the small intestines they cause the serious disturbances ascribed to them. 
These disturbances may be to a certain extent those arising from a re- 
flex irritation of the sympathetic and spinal nerves, but most of them 
seem to be due to the indigestion which the worms produce. The worms 
obstruct the intestinal canal by their great mass, irritate it by their ver- 
micular contractions, cause excessive secretion of intestinal fluids, non- 
assimilation of food, and abstract nutriment from the intestinal con- 
tents for their own growth. 

The lambs become poor and hide-bound; their flanks may either be 
distended by gas in the bowels or be tueked up from gauntness. 
In the progress of the disease the animals become evidently weaker, 
the mucous membranes paler, and the fleece dry and harsh from the 
loss of its yolk. The animals walk with a tottering gait. They often 
eat more and drink oftener than those less affected. In the severest 
cases the lambs grow extremely weak and poor, diarrhea becomes more 
and more pronounced, and at last they die through sheer exhaustion. 
While suffering from these worms they are more susceptible to the at- 
tacks of other parasites, and other diseases supervene and hasten the 
death of the already weakened animals. 

Prognosis.—Though the tape-worm disease in its mildest form is very 
destructive to lambs and yearlings, yet it would seem that if they are 
able to pass safely through a certain period they are very apt to re- 
cover. In 1887, in the examination of two wethers which two weeks 
before had been passing proglottides, or segments, in abundance, and 


120. 


from which it was expected to secure specimens for illustration, only 
a sinall piece of the worm was found, all the rest having passed away. 

Occurrence of the diseuse.—The worm, though present throughout the 
year, is more abundant in the locality of Washington during May and 
June than at any other season. This fact was doubtless somewhat de- 
pendent on the age of the lambs examined, which were about three or 
four months old at that time. In Colorado an outbreak was heard of 
in a flock of Merinos which occurred annually about July and August, 
after which time the lambs would improve. The disease is more prev- 
alent in the summer season, and causes the greatest damage in lambs 
less than six months old. If the young animals can be carried beyond 
this age they seem to be either better able to withstand the ravages of 
the parasite, or to have reached a season unfavorable for its develop- 
ment. 

Duration.—The broad tape-worms do not last long in theiradult state, 
but after maturing nearly all their segments are shed at once. From 
the time that the segments are shed the afflicted lambs will begin to 
receive and rapidly lay on fat. The disease leaves no traces other than 
debility in the early stages of recovery. 

Preventive treatment.—Treatment for the prevention of this disease is 
that suggested for general prevention of parasites and an observance 
of those measures which promote good heaith in the flock. Do not 
overstock pastures. Give good, pure water. When possible, put the 
lambs on new pastures. Feed some grain, put salt where the animals 
can take it daily, feed hay from racks, and grains, salt, and water frem 
troughs. 

The medical treatment promises better results than that for Tenia 
fimbriata, since the 7. expansa is never tound wedged into the gall duct 
or pancreatic duct, as is 7. fimbriata, but is found lower down in the 
small intestine, from whence it can be removed. Many of the popular 
tape-worm remedies are said to be efficacious, butas the disease is dif- 
ficult to diagnose until the worms begin to shed their segments much 
damage is done to the heaith of the lambs beforetreatment begins. On 
those farms and ranches where it appears periodically the lambs should 
be treated as soon as they begin to show symptoms. Even then com- 
plete cure can not be attained, for the lambs will continue to pick up 
eggs as in the first instance. For safety all sheep in the flock should 
be dosed, especially if all are to occupy the same pastures as those 
affected. 

Ziirn (Die Schmarotzer, ete., p. 191, 1882), says that treatment is 
practical when the disease is recognized before the lambs and yearlings 
are reduced to a cachectic condition. Although those far reduced in 
strength may not survive a medication, still they should be dosed in 
order that the parasites may be expelled. Otherwise the sick not treated 
should be yarded by themselves or killed and baried, so that they may 
not scatter eggs for further infection. Before giving the sheep any 


{21 


worm remedies they should be prepared by withholding food the night 
before and not watered on the morning of treatment. The dose should 
be administered at one time, allowing every animal to swallow it slowly 
if fluids are given. They should not be turned out atter dosing, but 
should be watched during the day to see if the worms are voided. If 
the worms are not passed off the dose should be followed by a cathartic 
on the next day. If it is certain that the sheep have tape-worms and 
none appear, the animals should be redosed with increased quantities 
on the following day. Of course particular attention must be paid to 
the purity of the drug given. 

After the sheep have been driven out the yard should be cleansed by 
removing the surface earth. This dirt should be placed where it can 
not be washed on to the grass to which the sheep have access; or, it may 
be thoroughly disinfected, burned, or buried. Cleansing the yard may 
Save a reinfection. 

Ziirn (0. ¢., p. 192) details experiments made by Schwalenberg, in 
which wormseed, Persian insect powder, petroleum, Chabert’s oil, ka- 
mala, kousso, and koussin were tried. The last three gave good results. 
In the first experiment 3.75 grams kamala (about 1 dram) were given to 
each Jamb. This dose caused diarrhea and removal of the tape-worms 
in forty-eight hours. The lambs remained poor for a long time, in spite 
of good care. 

In the second experiment 7.50 grams kousso (nearly 2 drams) given 
each lamb gave good results. 

Koussin, also known as teeniin or brayerin, in 12 centigram or 2-grain 
(loses, gave better results. The tape-worms wereexpelled. The treated 
animals remained cheerful, retained their appetites, and improved in 
condition. 

Pierie acid, 10 to 20 grains, made with meal and water into a pill, is 
also recommended for lambs. This quantity is sufficient for one dose, 
and should be followed by a cathartic. Epsom salts in 4-ounce doses 
is a good saline cathartic, or 4-ounce doses of the bland oils, adminis- 
tered slowly, may be used. 

The powdered male-fern root, in 2-ounce doses, is recommended, or 
the wtheric oil of male-fern in dram doses. The latter is the best. It 
can be given in combination with from 2 to 4 ounces of castor oil. Dr. 
H. Piitz (Sewchen wad Herde Krankheiten) recommends dosing in the 
morning, and withholding all food the night before giving the medicine, 
and on the following morning to give a cathactic. This may be unneces- 
sary, however, when the male-fern has been given with castor oil. 

Frohner (Thierdretliche Arzneimittellehre, 1889), gives the following 
recipes for lambs with tape-worms: Take of koussin 3 grains, and of 
sugar 10 grains, mix, and give at one dose. The dose of tansy is from 
2to6drams. It forms one of the chief ingredients of Spinola’s worm 
cake, which is fed to lambs as a preventive medicine against worms. 
The recipe, suflicient for one hundred sheep, is as follows: Take of 


‘ 122 


tansy, calamus root, and tar each 25 pounds; of cooking-salt, 14 pounds; 
mix ee with water and meal, make into cakes, and dry. This is an 
old and oft-repeated recipe, but I can not vouch for its efficiency. 

Powdered areca nut may be given to lambs in from 1 to 3 dram doses. 
If it does not produce a stool in three or four hours it should be fol- 
lowed by a cathartic. 

Ground pumpkin seeds are in repute with some, but it is difficult to 
induce sheep to eat the required dose. 

Tellor (Diseases of Live Stock, 1879, p. 3883) recommends salting liber- 
ally, and giving once a week the following saline tonic and bitter-lick 
as a preventive against worms: Take of common salt 2 pounds, sul- 
phate of magnesia 1 pound, sulphate of iron and powdered gentian, 
each half a pound, and mix with ground feed or fodder sufficient for 
seventy-five to one hundred sheep. This recipe is a very satisfactory 
one for improving the appetite and health of the sheep, but probaly 

san not be depended on for keeping the worms away. 

For tape-worm in sheep the same author recommends: Powdered 
areca nut, one-half to 1 dram; oil of male-fern, 10 to 20 drops; give in 
molasses and water, and follow the next day with a purge. For purges 
he gives two recipes: Sulphate of magnesia, 2 ounces; warmwater, 1 
pint in one drench; or, castor oil, 3 ounces; calomel, 12 grains; mo- 
lasses, 5 Ounces—for one dose. 

After the sick lambs have been treated, care and attention should 
not be relaxed, for it is of the utmost importance that they regain their 
strength and vigor before the cold weather sets in. The best pasture, 
an extra feeding of hay, and some roots and grain in judicious quanti- 
ties. should be allowed them. The feeblest should be kept by them- 
selves, Where they can get plenty of food and water without entering 
into competition with the stronger. This treatment should be kept up 
until they are fully able to hold their own. 


124 


TANIA EXPANSA, Rud. 


PATE NVic 


Figs. 1 and 2. Young tape-worms, natnral size. 

Fig. 3. Head end of tape-worm, drawn to show vermicular contractions when living. 

Fig. 4. Head, top view: a, a, the suckers or cups, by which the worm attaches 
itself to the intestinal walls. 

Fig. 5. Head, side view : a, a, suckers ; b, b, folds in the neck; ¢, c, the first segments. 

Fig. 6. The large end of a young tape-worm: a, a, segments which are not mature 
enough to drop off; b,b, segments ready to pass away from the worm. 

Fig. 7. Segments, or proglottides found, separate from the worm. 

Pig. 8. An adult tape-worm, drawn in sections at regular intervals apart: a, head. 

Fig. 9. A fragment of another worm, which is not only slightly larger, but whose 
segments are shorter and broader. 

The specimen shown in fig. 8 could have assumed very much the same form when 


alive as is seen in fig, 9. 


Ce 
- 


PLATE XIV 


5 
B 
i 
2 
s 
eB 
A 
& 
% 
5 
ce 
= 
< 


SD eo 


LI 


Tape-Worm.) 


awl 


BTOPVAORUIBENNNNEE 


‘TAENIA EXPANSA, 
(The Broad ‘Tape- 


et 
: 


7 


“5 


Geo. Mare, del. 


a 


8. 


oh 


. 10, A head of young specimen showing a peculiar loop in it, 


126 


TASNIA EXPANSA EMBRYOS. 
PLATE XY. 


Embryos magnified and tlattened under cover-glass. 

A single embryo and its enveiopes somewhat flattened. 

The same greatly flattened: a, the thick, oily mass between the inner and 

outer covering, 

The same with outer envelope ruptured: a, the outer envelope; 6, the in- 
ner; c, oil globules; d, the embryo and its pyriform apparatus. 

Embryo, with three envelopes. 

Embryo escaped from ruptured inner coat: a, the fringed cap-like covering; 
b, the bladder-like sac protuding from it; ¢, the six-hooked embryo. 

A younger embryo, inwhich the bladder portion has not burst from the cap, 
a, the cap; 6, the embryo. 

Three young tenia which show no trace of segmentation. 

A young tenia which is beginning to segment. 


A.Hoen & Co. Lith, Baltimore. 


TAENIA EXPANSA 
_ (Young Stages.) 


THE LIVER FLUKE--LIVER-ROT. 


DISTOMA HEPA'TICUM, Linn. 
Plate XVI. 


The liver fluke disease, which causes so much loss in Great Brit- 
ain and on the Huropean continent, is comparatively unknown in this 
country ; so rarely, indeed, is it discovered that most authorities on the 
management and care of sheep seem never to have seen it. That it 
has occurred in this country, and that it is present in certain portions 
of it, is tolerably certain, for good observers have recorded it at various 
times. 

Henry Stewart, in the Shepherds Manual, 1882, page 223, says that 
flukes were found in a flock of Southdowns at Babylon, Long Isiand, 
and also in Cotswold, Leicester, and native sheep, presumably at the 
same place. In the Tenth Census Reports of the United States, Vol. IIT, 
flukes are said to occur in Texas and California. In the latter State 
they have been seen by Prof. E. C. Stearnes, of the Smithsonian Insti- 
tution. 

The disease occurs so infrequently in this country that the writer has 
seen but two cases of it, and both of these were in cattle. For a de 
scription of the malady we will therefore have to depend upon writers 
in those countries where it occurs more frequently than it does here. 

Description.—Body flattened, leaf-like, pale brown, irregular, the adult from 18 
to 31™™ long, from 4 to 13™™ wide, oblong, oval or lanceolate, larger and rounder in 
front, where it is abruptly contracted in such a way as to present a conical neck; 
attenuate and obtuse behind. Skin bristling with numerous little points directed 
backward. Oral sucker terminal, rounded. Ventralsucker large, projecting, with a 
triangular opening situated about 3™™ behind the first. Intestine with two rami- 
fied branches visible through the skin and of a deep shade. Penis projecting in 
front of the abdominal sucker, always recurved. Vulva very small, situated at the 
side of the male orifice or a little behind. Eggs brown or greenish, ovoid; length 
from 0.130 to 0.145™™ ; width from 0.070 to 0.090™"™, (Neumann.) 

Occurrence.—This parasite has been found in the livers of sheep, 
goats, cattle, camels, and certain wild ruminants. It has also been 
found in the horse, ass, pig, elephant, rabbit, and man. It lives in the 
biliary ducts of the liver, and, according to Kiichenmeister, feeds on 
blood drawn from the mucous membranes of those passages. The par- 
asite does not appear to be equally abundant at all times in Europe, 
but seems to develop at various periods in sufficient numbers to cause 
epizootics. A number of these outbreaks, compiled by Neumann, 0. ¢., p. 

127 


128 


463, demonstrate no periodicity or law by which future outbreaks may 
be suspected or predicted. 

Sheep-owners and veterinarians are agreed that damp, wet seasons, 
and damp pastures are favoring conditions for the development of the 
parasite and promotion of the disease. 

The life history of the parasite has been determined by Leuckart in 
Germany, and a little later, but apparently independently, by A. P. 
Thomas, in England. The former published his observations in Zoolo- 
gischer Anzeiger, December 12, 1881, and October 9, 1882, and the lat- 
ter in the Journal of the Oa Agricultural ean of Haglan Vol. 
XVIII, part 2, 1882, and Vol. XLX, parts 1 and 2, 1883. These authors 
have described most of the stages in the life ae of the parasite, 
leaving but little to be said in addition. 

The egg of the fluke passes from the biliary passages through the in- 
testine to the ground (Plate XVI, Fig. 2a). Those that fall in favorable 
places develop (Fig. 2b) and finally break the little lid off the end of 
the shell (Fig. 2c) and escape. This happens in summer and occupies 
from three to six weeks. At this stage (Fig. 3) the whole body is covered 
with fine cilia (hairs), which enable the embryo to swim about in the 
water. At one end of the embryo is a little projection which can be 
thrust out and withdrawn, and is the apparatus by which it bores into 
its second host. If it dces not meet one in a day or two it dies. If it 
meets a water snail (Fig. 6 and 6a), it is not slow to penetrate into the 
body, where, according to Leuckart, it lodges in the respiratory cavity. 
Here it encysts itself (Fig. 4), contracts into an oval mass, and rapidly 
grows. The name sporocyst has been applied to this form. The con- 
tents of this sporocyst split up into a number of bodies (lig. 4), usually 
from five to eight, which develop into redie (Fig. 7). Their length 
at this stage is about 2™", or one twelfth of an inch. ‘These are ex- 
cluded from the sac one by one through a rent. Now each redia, in 
its turn, develops from fifteen to twenty cercarie (Fig. 8) within it, which 
are evacuated in turn through an unpaired orifice situated under the 
neck of the redia. The cercariw are the forms that escape from the 
snail, and are scattered by it in its wanderings. The cercaria, after a 
time of active life, loses its tail, which it has developed, and again en- 
cysts itself. (See Figs. 11 and 12 and Fig. 10.) The contents of the 
cyst still more resemble the future fluke, and itis at this stage that 
the sheep swallows it with grass. Itthen breaks from the cyst, arrives 
at the stomach and duodenum, to finally make its way into the biliary 
canals aud grow into another, adult hermaphrodite, capable of giving 
rise to other generations of young. 

According to Thomas the encysted embryo (Fig. 4) may give rise to 
daughter rediz or to cereariz, the former to develop in the summer and 
the latter during the cold season, 

The epitomized life history is first the egg ; second, the embryo, which 
encysts in a snail; third, five te eight redize, deyeloping from the cystic 


£29 


larva; fourth, fifteen to twenty cercariw, developing from each redia 
and escaping from the snail; fifth, the encysted cercarie, which after 
havipg been swallowed by a lamb develop into adult flukes. 

This life history is fully as wonderful as any occuring in nature. Ac. 
cording to it, at least seventy-five young flukes under favorable sur- 
roundings could develop from a single egg. As the proper conditions 
are scarcely ever fulfilled, there are but few of those which meet with 
all the requirements for development. 

The disease created by these peculiar parasites is known by many 
names, the most popular of which is Liver Rot, a term expressive of the 
chief pathologic symptom. Aqueous Cachexia, Rot, Rot Dropsy, Sheep- 
Rot, Liver-Disease, Liver Fluke, Jaundice, Yellows, Verminous Phthisis 
of the Liver and Ictero-Verminous Cachexia, are other names for the 
disease, each being expressive of some of its symptoms. 

The symptoms, according to Neumann (Maladies Parasitaires), to whom 
the writer is indebted for the greater part of this article, may be divided 
into four periods, viz: 

(1) Period of immigration.—This is the period in which the parasite 
invades the liver. In this stage the flukes are small and do not cause 
excessive disturbances. This period lasts from four to thirteen weeks. 
It is probable that it lasts as long as the weather remains favorable 
for the development of young flukes aud sheep are kept on infested 
pastures. 

(2) Period of anemia.—This ordinarily coincides with the months of 
November and January, or after the lapse of thirteen weeks from infec- 
tion. The sheep are less lively; the mucous membranes about the eyes, 
the nose, and the gums, the internal surface of the ears and the skin, are 
all paler than in well sheep. The appetite is still good, and the animals 
have a tendency to fatten, caused, according to Simonds, by a better 
assimilation of food from the increased flow of bile stimulated by the 
young flukes. This fattening stage has been taken advantage of in 
‘England by a dealer (Bakewell), who purposely exposed the lambs he 
wished to market early to the disease, that he might send fat lambs into 
the market five or six weeks ahead of his neighbors. Sometimes the 
appetite diminishes, thirst increases, and rumination is irregular. The 
conjunctiva, the mucous membranes of nose and mouth, and the skin 
are white, slightly tinged with yellow. There is a slight oedema (putf- 
finess); the skin is looser, feels pasty and soft to the touch where bare; 
the conjunctiva is infiltrated and puffy and the eye partially closed ; 
the wool becomes dry and brittle, is easily puffed off, and sometimes 
falls off of itself. Weakness appears more and more marked. There 
is sometimes fever and quickened breathing. Palpation and percussion 
indicate ascites. The droppings are normal, but contain at the end of 
this period numerous fluke eggs, Death may result in this stage from 
apoplexy. 

23038 A P-—9 


130 


(3) Period of loss of flesh.—The sheep begin to become leaner at the 
end of the third month after the immigration of the larvae, or about 
the beginning of January. The malady is then at its height. The 
animal becomes gradually leaner; the mucous membranes and the skin 
are bleached, and lose the yellow tinge. The temperature is variable 
and is highest in either the morning or evening. Respiration is feeble 
and frequent. The appetite keeps up, and the feces present nothing 
in particular except fluke eggs. The urine is nearly normal. The ani- 
mals are listless and dejected, carry their heads iow, and give way when 
pressed on their backs. There are frequent abortions. Nursing ewes 
have a clear, watery milk, very poor in nutritiveelements. Their lambs 
are weak and thin, and usually die unless they are put to another nurse. 
The cedema becomes localized and increased in dependent parts. It is 
dispelled by walking and comes again in rest. The space under the 
jaws and along the trachea is a frequent seat of puffiness. This disap- 
pears during rest and comes on during feeding. It is often absent 
with adults in hot seasons. In the three weeks which follow the ani- 
mals become still poorer despite abundant feeding, and there is gener 
ally diarrhea, ceedema, jaundice, and pain on pressure over the liver. 
Hither death occurs at this period, or the animals improve and enter the 
next period. 

(4) Period of emigration of the flukes.—This is the period of convales- 
cence and of spontaneous cure. All the symptoms grow less and finally 
disappear, but the cure is never complete, the changes which have taken 
place being irreparable. The recovery of affected sheep is exceptional. 

Duration of disease.—The flukes are said by some authors to remain 
nine months in the liver, by others fifteen months. After this time they 
make their way into the intestine and are evacuated with the excre- 
ments. 

Thomas says that he has seen the sickness last six years, and Neu- 
mann seems to coincide with Perroncito, that the flukes have little ten- 
dency to quit their hosts. The question of reinfection of the same ani- 
mal would leave it doubtful whether such long period of infection were 
all due to the same parasites or to renewed generations of them. 

The duration of the disease, which, as a rule, is variable, depends en- 
tirely on the degree of infection and the treatment, hygienic and me- 
dicinal, which they receive. It ordinarily lasts about six months, but 
exceptionally may have an extremely rapid course of a few days, death 
being caused by an acute inflammation of the liver, set up by the para- 
sites, and occurring in from seven to nine days after the first appear- 
ance of the disease. Weakened by the fluke disease, the animals are 
more susceptible to other maladies, and these may destroy them before 
the primary disease has run its course. 

Diagnosis.—There is little difficulty in diagnosing liver-rot in the 
stages at which it is first noticed if the flock-master sacrifices one of the 
worst affected sheep. Although he may think that it hardly pays to 


131 


kill a sheep to find out what the trouble is, he will subsequently learn 
that-a little loss in the beginning leads to a great saving in the end, and 
therefore becomes an investment. 

In fluke disease not one or two lambs only are infected, but all the 
flock that have been feeding together. If the flock-master has a micro- 
scope he can detect eggs of the fluke in the droppings, but this ean only 
be found after the fluke has matured and the disease has well advanced. 
Besides, it requires some skill to make the required examination. So 
numerous are the eggs and so characteristic is the shell with its little 
cap, however, that this method forms an important element in diagno- 
sis. The droppings should be moistened with water and thoroughly 
picked to pieces, then spread evenly on a piece of glass and covered by 
another thin glass. The mass should be closely examined with the aid 
of a microscope magnifying from 70 to 80 diameters. This operation 
should be repeated a number of times if eggs are not found. The ex- 
amination of the liver is the best means of diagnosis. When the gall 
ducts are cut open the young flukes will be found in them, They usu- 
ally occur in smaller or larger nodular swellings. The structure of the 
liver is also characteristic, presenting a dark, soft, rotten appearance. 
Young flukes can be found by cutting into this organ and washing it in 
water. After allowing everything to settle, pour off the top and repeat 
the operation until the contents of the dish can be distinguished. When 
spread out on a flat-bottom: d dish the flukes may be easily distinguished 
by the unaided eye, or, if very young, by the help of a small lens. If 
the sheep has been killed the flukes will be seen to weiggle and curl, 
for they die slowly in water ordinarily warm. 

Prognosis.—The disease is very tenacious, and when once on a farm 
is difficult to extirpate. Many farms in infected localities are rendered 
useless for sheep raising by these parasites. When a flock becomes 
infected it is not to be expected that the disease will be stopped until 
it has caused extensive damage, and that only the most prompt and 
effective measures will save any of the afflicted animals. 

Pathology.—The disease is seated in the liver, and all the symptoms 
and changes observed in other parts are directly dependent on those 
occurring in this most important organ. The different periods into 
which the various alterations have been divided are directly dependent 
on the periods in the life history of the flakes. For our present purpose, 
however, it seems advisable to give but the most brief description of 
these pathologic changes. 

When the flukes first invade the liver they cause an inflammation, 
which is shown by a thickening of its mass. It becomes softer, and 
the surface, which should be smooth and glistening, becomes rough. 
These changes increase as the days go by, and the liver becomes softer 
and thicker. The surface becomes covered by thready fibers, as well 
as inuch rougher; the abdomen contains more or less dark-colored 
serous fluid; young flukes from one-tenth to one-fifth of an inch long 


132 


can either be found in serum-filled cavities of the liver or attached to 
the outside, or perhaps free in the cavity. Still later, the liver shows 
places puckered up, which are caused by the reparative process and the 
contraction of the newly-formed tissue. There will be numerous chan- 
nels beneath the serous membrane visible to the unaided eye. The bil- 
iary canals will be found thickened and enlarged at places to the size 
of a hazel-nut, or even larger. In these dilatations are flukes of con- 
siderable size, surrounded by a greenish black, sticky mass. Some- 
times hard limy fragments are found in them. The substance of the 
liver becomes very rotten, and crackles under pressure by the finger. 
When the flukes migrate healing takes place to some degree, but the 
liver will never Jook healthy. It will grow considerably smaller and 
become much whiter, due to the connective tissue changes which take 
place. ’ 

Preventive treatment.—Thomas has formulated rules of prevention 
against this parasite, which are founded on its life history and seem to 
be eminently practical. He says 

(1) All eggs of the liver fluke must be rigorously destroyed. Manure of rotten 
sheep or other infected animals must not be put on wet ground. As the liver and 
intestines contain eggs, these, too, must be destroyed or put in the compost heap. 
The manure of affected animals should not be stored where there is a drainage from it 
to the neighboring grass. It should be mixed with lime and salt before being spread 
on meadows or cultivated fields. 

_ (2.) If sheep are infected, let them be sent to the butcher at once, unless they are 
specially valuable and are not badly affected. If kept, they must not be put onto 
wet ground. 

The above advice is preferable with all common stock; and the ex- 
ceptions, when medicine should be tried, are very few. Stock should 
be very valuable to repay the expense of care and treatment in face of 
the large percentage of death which occurs in this disease, and the ill 
condition of the remnant after. recovery. 

(3.) Care must be taken to avoid introducing eggs of the fluke either with manure 
or fluked sheep, or in any other way. Rabbits and hares must not be allowed to in- 
troduce the eggs. 

The most prolific source of introducing parasites is in the introdue: 
tion of infected sheep, and purchasers should learn all they can of the 
history of the animals they buy, and not purchase from diseased flocks. 

(4.) All heavy and wet ground must be thoroughly drained. 

Draining is of advantage in many ways. It makes tillable land of 
what was before useless, either for pasturage (as shown by its infecting 
the flocks with a fatal dineane) or for cultivation. 

(5.) Dressings of lime and salt (or both) should be spread over the ground at the 
proper season to destroy the embryos, the cysts of the fluke, and also the snail which 
acts as host. 

After draining, such fields should be cultivated and suitable crops 
raised on them. 

(6.) Sheep must not be allowed to graze closely, for the more closely they graze the 
more fluke-germs will they pick up. 


133 


This rule is advisable wherever the sheep may pasture. Sheep on 
over-stocked pastures do not get enough grass, and become more in- 
fested with worms from having to eat close to the dirt. 

(7.) When sheep are allowed to graze on dangerous ground they should have a daily 
allowance of salt and a little dry food. 

Exigencies can be conceived in which sheep may be allowed to pas- 
ture on infected ground, but, in view of the fatality attending the 
malady, it would seem more profitable to sell the animals while they are 
still in good condition than to expose them further to these parasites. 

Lime and salt are the two cheap preventives against this parasite. 
The former, mixed with manure, increases its value as a fertilizer. A 
solution of three fourths of 1 per Gent. of salt in water has been found 
by experiments in the laboratory to kill fluke embryos. This weak so- 
lution might prove too weak in the field, when the salt would be still 
further diluted by dew or rain. Perroncito has shown that the encysted 
cerearie and the larve encysted in Limnea palustris die in 2 per cent. 
Salt solutions in five minutes; in 1 per cent. solutions they die after 
twenty or thirty-five minutes; 0.65 per cent. solutions kill in about the 
same time; in 0.25 per cent. solutions the worms live after twenty 
hours’ immersion. 

The weakness of the brine necessary to kill the parasites in the labo- 
ratory points out that a small proportion of salt mixed with the lime 
would be very advisable. Salt was first advised from a knowledge of 
the fact that sheep never became infected with flukes on salt marshes. 
Stronger solutions of salt also kill the snails, which are the hosts of the 
embryonic fluke. 

The time of year for scattering the lime or salt on the fields is the 
first part of June, July, aud August. 

Neumann advises mixing two teaspoonfuls of salt for each sheep 
with the ground grain they eat. Perroncito advises the addition of 
one-half of 1 per cent. salt to the water they drink (about a heaping 
tablespoonful to each gallon of water). 

Aithough the flockmaster can never completely cure his sheep, he 
may, by judicious medication, so improve the condition of the con- 
valescent animals that they will take on considerable flesh. Many 
vegetable astringents and tonics have been tried, with more or less 
profit, but it is to the mineral astringents that we look for the best re- 
sults. Sulphate of iron and common salt, dissolved in the drink or 
mixed with the food, are among the best and cheapest. 

Medicinal treatment.—Some experimenters have endeavored to kill 
the flukes, and have met with varying success. The remedies tried 
have been extract of male-fern, given with turpentine or benzine, castor 
oil, etc. For proportions of these remedies see remedies for Tenia ex- 
pansa. Mojkowski, according to Neumann, has obtained encouraging 
results against the distomatosis (the fluke disease) of sheep with naph- 


134 


thaline, given twice a day during a week, in from 10 to 15 grain doses, 
alone, or mixed with powdered gentian. 

The following recipes, to be used as licks, may be useful in small 
flocks : 

Take of sulphate of iron, 2 ounces; calamus root, 1 pound; of crushed 

oats and roasted barley malt, of each, 20 quarts. This quantity is 
sufficient for one hundred sheep. Other mixed grain may be substi- 
tuted for the barley-malt and oats. Or, sulphate of iron, 1 ounce, and 
powdered juniper berries and gentian root, of each, 1 pound. Mix 
with 20 quarts of grits. <A lick for fifty sheep. 

A very complicated but apparently good tonie remedy is known as 
Spinola’s worm-cake, see page 121. Vieth recommends the following: 
Oak bark, calamus, gentian root, and juniper berries, of each 2 pounds. 
Pulverize and add pulverized sulphate of iron, 1 pound; pulverized cook- 
ing-salt, 10 pounds. Mix thoroughly, and give each sheep a teaspoonful 
every two or three days. The medicine is most easily administered 
mixed with meal, chops, bran, ete. Either of the vegetable ingredients 
of the above recipes can be omitted and substituted by some other well- 
known tonics, though each is thought to have its special virtues. The 
dietary treatment is the most valuable. Grain-feeding, mashes, strong 
meals, as flax seed meal cakes, or cotton-seed oil cakes, can be given in 
judicious quantities. The general treatment should embrace every 
means known to the flock-master to sustain the health of the flock. 

Police sanitation.—The meat of sheep affected with liver-rot is safe to 
eat, butin advanced stages of the disease it is too watery, lean, and in- 
nutritious to be wholesome food, and is only an inferior article. When 
killed during the early stages of the disease it is more salable and nutri- 
tious. Later on, it should not be put on the market or received by 
buyers. 


Fig. 1. 
Fig. 2. 
Fig. 3. 
Fig. 4. 
Fig. 5 
Fig. 6. 
OTe Ue 
Fig. 8. 
Fig. 9 
Fig. 10. 
Fig. 11. 
Fig. 12. 
Fig. 13. 


136 


DISTOMA HEPATICUM, Linn. 


PEATE excel. 


Adult fluke, natural size: la, young fluke, natural size, (Raillet.) 

Eggs: a, egg with developing embryo; b, egg with embryo; c, egg-shell. 
(Raillet.) 

Ciliated and free embryo: a, perforating apparatus ; b, ocular spot. (Leuck- 
art.) 

Encysted embryo found in snails. (A. P. Thomas.) 


. Diagram of digestive apparatus and nervous system: a, mouth sucker; b, 


pharynx; ¢, esophagus; d, branches of intestine; e, their branchlets ; 
f, nerve ganglia; g, ventral nerve. (Raillet.) 

Limneus truncatulus, the principal snail which is the larval host of the fluke 
in Europe: a, natural size. (Raillet.) 

Redia of Distoma hepaticum: a, mouth; b, pharynx; ¢, digestive tube; d, 
the so-called germinative cells destined to produce cercarie. (Leuckart.) 

Redia containing cercariw: a, mouth; b, pharynx; ¢c, digestive tube; d, d, 
cercarize. (Leuckart.) 


. Cerearia dissected from its cyst: a, anterior sucker; b, ventral sucker; c, 


pharynx; dd, branches of the intestine terminating in ceca. (Leuckart.) 
Grass stalk with three encysted young flukes, a,a. (A. P. Thomas.) 

Free-swimming cercaria just before it is about to encyst. (A. P. Thomas.) 

A slightly older stage than Fig. 11. (A. P. Thomas.) 

Genital apparatus of the liver fluke: a, digestive tube; 6b, ventral sucker; 
c, anterior testicle; d, its deferent canal; e, posterior testicle ; /, its def- 
erent canal; g, seminal veside; h, genital sinus; 7, cirrhus pouch; j, 
ovary; k, oviduct; 1, shell-gland; m, yolk glands; n, longitudinal and 
0, transverse yolk-gland canals; p, uterus; g, vagina. (Raillet.) 


PLATE XVI 


A.Hoen & Co, Lith, Baltimore, 


DISTONIA HEPATICUM 
(The Liver Fluke.) 


137 


DISTOMA LANCEOLATUM, Meblis. 


Plate XVII, Figs. 11 to 15. 


Description.—Body semi-transparent, spotted with brown by the eggs, length from 
4 to 9™™, width 2.5™™, lanceolate, obtuse behind, attenuate forward, and terminated 
by the oral sucker, which is nearly as large as the ventral. Integument smooth, 
intestine with two branches, not further subdivided. Penis long, generally straight. 
Genital orifices very close to one another. Eggs ovoid, length from 0.037 to 0.040™™, 
(Neumann. ) 

The life history of this parasite seems to be as yet unknown, but it is 
believed to be analogous to that of Distoma hepaticum. The embryo 
(Fig. 11) differs from that of D. hepaticum in being globular, armed with 
a cephalic spur, and in being ciliated only over the anterior third of the 
body. Its movements are said to be slower. 

Ercolani has shown that young embryos measuring 1™™ first show 
traces of a digestive system (Fig. 14), and that the digestive system is 
preceded by groupings of cells, which first outline the testicles, then the 
penis, and lastly the ovaries. Two species of snails, Planorbis margi- 
natus and Helix carthusina, which contained cereariz, have been pointed 
out, the former by Willemoes-Suhm and the latter by Piana as the in- 
termediary hosts of the fluke. 

This species of fluke never produces symptoms or lesions as gra¥e as D. hepaticum, 
and can only occasion aqueous cachexia or dropsy. This relative harmlessness is at- 
tributed by Leuckart to its small size and the absence of spines on the skin. The two 
species are most often found together in the same host. By reason ofits minute size, 
D. lanceolatum penetrates into the finest biliary canals, where the young D. hepaticum 
can not enter. Because the individuals of the former species escape observation on 
account of their small size they appear to be fewer in number. Friedberger has ex- 
tracted some thousands from the biliary passages by squeezing the liver. They are 
also found in great numbers in the gall bladder and in the intestine at the time of 
their emigration. (Neumann.) 


The means of prevention and treatment are the same for this as for 
Distoma hepaticum. Treatment is of more avail. 


PARASITES OF THE RUMEN. 


AMPHISTOMA CONICUM, Zeder. 


Plate XVII, Figs. 7 to 10. 


Body of a rose tint, irregular, and more or less dark. It is ovoid, narrowed in front, 
and swells gradually even to the posterior end; obtuse and slightly recurved on the 
ventral face. Length from 10 to 13™™, width behind from 2 to 3™™, (Neumann.) 

This parasite has been found in sheep in India and Australia. The 
author has not observed it in this country. Itoc2urs scattered amongst 
the large villi of the rumen or first stomach, attached by its posterior 
sucker. It is said to cause but little digestive disturbance. Figures 
and description of this parasite are presented, as it is a representative 
of the genus, and may sometime serve for generic determination of 
allied parasites which may be found in this country. 

138 ° 


~ 


140 


_LINGUATULA TAENIOIDES, Rudolphi. 


PLATE XVII. 


. Male, natural size. (Cobbold.) 

. Female, natural size. (Cobbold.) 

. Egg with contained embryo. (Leuckart.) 

. Embryo escaped from egg-shell. (Leuckart. ) 

. Pupa nine weeks old: a, anus; b, mouth. (Leuckart.) 
. Linguatula denticulatum. (Leuckart.) 


AMPHISTOMA CONICUM, Rudolphi. 


. Piece of the rumen of a cow, showing the parasite attached between the 
papille by their large posterior sucker: a, an isolated individual, natural 


size. (Raillet.) 


- Dorsal view, X2. ( Blanchard.) 
. Lateral view, X2. (Blanchard.) 
. Egg of an amphistoma, X80. (Cobbold.) 


DISTOMA LANCEOLATUM, Mehlis. 


, Ciliated embryo. (Leuckart.) 
2. Early stage of development, in which there is no digestive apparatus. 


(Ercolani.) 


. Another stage: a, a, groups of cells representing the future testicles. 


lani.) 


. Stage showing the testicles plainer, a,a; b, the rudimentary cirrhus pouch, 


and ¢, the digestive system. (Ercolani.) 


. Adult, natural size figure by its side: a, pharynx; 5b, cesophagus; ec, branches 
of intestine; d, ventral suckers; e, e, testicles; f, f, deferent canals; g, cir- 
rhus pouch; kh, ovary; i, albuminous glands; k, uterus; 1, vagina. 


PLATE XVII 


NOHO a 
nwt 
UTA 


ig 


anit 

H unin 

vA TLALN aly manne 

i i i Mau non me: 
RUSH HT eH vei neat eq iM yy( (AUN ee ee 
Bi VITUS AAT NO 
STAT TTT SEU COE 

CAPO TEL yin y: 

HCUUERRUALENT MRRINTT LUNIA Re 


STOTT A 1 
SUT EET aLAAN P ne) 
ASAHI} Yiusiast4sel| uN! 
VOVTTURSETLET OD | (A 
TUTORED HDS 
SETAE nD 
NOS OREESTERNYON OL 
SEM Bee 
intial oy 
ANY ALUN) LL APU AMEEY 
(COPY Oo 
SREY 
LAAT 


ren 
fn) 
SSO 
WTEC TTL 
TT en 
TOE 
OUT) Tn 
SH UT PT 
CY Ta 
EE AT 
AL icicedPitat 
a 


MA yiie 
BaD nL bari 


Haines, del. A.Hoen & Go. Lin) Bolnme re 
LINGUATULA TAENIOIDES. AMPHISTOMA CONICUM. 


DISTOMA LANCEOLATUM. 


THE STOMACH ROUND WORMS. 


STRONGYLUS CONTORTUS, Rud. 


Plate XVIII. 


Strongylus contortus, or the twisted strongyle, is an inhabitant of the 
fourth stomach of sheep and goats. Though in the majority of flocks 
it produces but little if any disturbance, yet there are times when, in 
connection with other species, it causes disease which may carry off 
numbers of lambs. In the southwestern States and Territories the 
disease has been called lombriz, a corruption of the Spanish word lombrici, 
meaning worms. The later writers seem to be inclined to attach a 
specific meaning to this word, while the Mexicans, who used it, merely 
intended to say that the lambs died of worm disease. 


Description.—Female, 18 to 380™™ long; male, 15 to 20™™ long; body reddish; 
female marked by a double spiral white line, thicker toward the caudal end. The 
skin shows eighteen longitudinal lines. The mouth is round and without visible lips 
or papille. The neck has two barb-like side papillie; unicellular glands scarcely 
visible. The male is about two-thirds as long as the adult female, and shows no 
spiral line. Bursa deeply bilobed, with a small dorsal lobe attached to one of the 
pair. The lobes are somewhat longer than broad. The ventral cost are separated ; 
the lateral are double and separated ; the dorso-lateral is attached to the lateral group 
near its base; the dorsal costz support the dorsal lobe and each branch is double; 
the twofold character is indicated by a little notch. The lateral cost are irregu- 
larly divided, many variations being observed, Spicula two, embracing a chitinous 
piece between them. They are short, cylindrical, barbed on one side near the end, 
and have blunt tips. Female: Vulva 3™™ from the tail and covered by a nipple- 
like projection, 0.5™™ long; the latter has thin borders, and is coneavo-convex, to fit 
the body when pressed against it.. Uteri two, each opening into the common vagina ; 
one is anteriorly directed and the other posteriorly, with a short loop between it and 
the vagina. The ovary of the posterior uterus is reflected anteriorly to rejoin its fel- 
low, and together they wind spirally around the dark-colored intestine. The ovoid 
eggs are laid in the gastrula form, or after they have passed through the segmenta- 
tion stage; length, 0.070 to 0.097™™; width, 0.043 to 0.054™™, 


Occurrence.—This worm may be found in all stages in the fourth 
stomach or abomasum of sheep. When collected immediately after 
death from a slaughtered sheep they may be detected adhering by their 
heads to themucous membrane. They are then of a reddish color, which 
may be because they feed in part upon the blood of the victim. 

The life history of Strongylus contorlus seems to be apparently simple. 
Among a number of lambs kept at the Experimental Station in 1888 
were two or three which had been raised there. <A post-mortem exami- 

141 


142 


nation of one of these, with four other lambs which had been at the 
Station for the five previous months, revealed numbers of Strongylus 
contortus in all stages of growth, and of Dochmius cernuus, Trichoceph- 
alus affinis aud Tenia expansa. These lambs were supplied with well wa- 
ter, and were allowed torun in a sinall, dry, grassy yard connected with 
a stable. The presence of these species of all sizes in the former group 
of lambs showed that they acquired them on the place, and that their 
development was direct; that is, they did not pass through a secondary 
host in passing between the sheep and thelambs, for all of the conditions 
were under inspection. The grass in the yard became very short, and 
probably it was because the sheep ate it so close to the ground that they 
became more infested with worms than sheep ordinarily do. The his- 
tory, therefore, is probably as follows: The eggs fall to the ground; 
they are eaten by other sheep along with their feed, and they then ar- 
rive at the stomach and develop there. 

The disease they cause can not easily be distinguished from that pro- 
duced by other intestinal parasites. In the worst cases, besides a gen- 
eral lack of tone and good health, there is weakness, paleness, some 
fever, diarrhea, ete. In fatal cases death is said to occur within a very 
few days after the illness is observed; but, as the parasites develop 
slowly, it is probable that no symptoms of illness are apparent until 
after the lambs have been ailing for some time. <A positive diagnosis 
is to be made only by a post-mortem examination. The little worms, if 
present in large numbers, will appear like masses of threads lying in 
the stomach. If the sheep has been killed for examination, the worms 
will be seen wriggling and squirming in all directions. 

Treatment.—Various remedies are proposed, but of those available 
an emulsion of milk and turpentine, prepared by shaking the mass well, 
seems most practicable. Add 1 part of spirits of turpentine to 16 parts 
of milk, and give from 2 to 4ounces of it to each animal, according to age 
of patient. One dose should be sufficient; if not, repeat it in three or 
four days. Or, take of linseed oil, 1 ounce; turpentine, one-half ounce, 
shake well and give as onedose. Quantities sufficient for any number 
of sheep may be made up in these proportions. 

The following recipe is from Finlay Dun’s Veterinary Medicine: 
Common salt, 3 pounds; powdered ginger and niter, halfa pound each ; 
dissolved in 3 gallons of warm water; add 24 ounces of turpentine 
when nearly cold. The dose for iambs between four and six months’ 
oldis 2 ounces. The entire quantity is sufficient for one hundred and sixty 
Jambs. For delicate lambs, which are coughing and purging, the same 
writer recommends oil of turpentine, powdered gentian, and laudapum, 
2 ounces each, all to be dissolved and stirred in 1 quart of linseed tea 
or lime water. This quantity is sufficient for ten or twelve doses. 

Ziirn recommends (after Rabe) the picrate of potash, because it is 
less irritating to the patients. The dose for a lamb is from 24 to 5 
grains; for an adult up to 20 grains. It can be given dissolved in 
water. 


143 


Dr. H. J. Detiners, in a report to the Commissioner of Agriculture, 
1853. on the diseases of sheep in Texas, recommends the use of tartar 
emetic as follows: A half pound of tartar emetic is to be dissolved in 
12 quarts of water, and from 1 to 2 ounces of the solution, containing 
from 5 to 10 grains of the remedy, is to be given each patient, depend- 
ing on its size. He recommends dosing out of a small 2-ounce vial, 
and in small swallows. 

Good, nourishing food, and a dry yard in summer, or a healthy, well- 
ventilated stable in fall and winter, are advisable. In giving medicine, 
drench from a horn, a spoon, ora stout glass bottle. Bottles are always 
liable to break. Let an assistant throw the sheep onto its hauuches 
and hold it between his legs, back toward him. With the lower jaw 
seized in his left hand, from the left side, he can either seize the upper 
jaw or pull out the cheek-pouch with his right. The medicines are 
best administered while the sheep are thirsty. Small doses may be 
diluted, but a dose of 4 or 6 ounces is m»re apt to run directly into the 
fourth stomach than larger doses; otherwise, some of the latter might 
be diverted into the second stomach and fail of an immediate effect. 

The following recipe was recommended to the readers of Field and 
Farm, August 7, 1889, as a preventive remedy for worms in sheep. Mr. 
G. B. Bothwell, of Breckenridge, Mo., who used it for fifteen years with 
success, is its author. 

Salt, 1 bushel; air-slaked lime, 1 peck ; sulphur, 1 gallon; pulverized rosin, 2 quarts; 
put in trough with cover, where sheep can have free access. When sheep become 
thoroughly infested with worms death is almost sure to follow, but the above, if 
kept before the sheep, will surely act as a preventive. 

A more complicated arsenical recipe for worms, the source of which 
is unknown, is as follows: 

Take of arsenic, washing soda, and carbonate of soda, each 1 ounce; 
put them into 2 quarts of hot water; boil, and stir for one-half hour, 
then add 10 quarts of cold water. The dose for a lamb, after weaning, 
is one-third of a gill. If the lamb is not very sick give but one dose, 
but if badly affected repeat in nine days. 


Fig. 


9. 


144 


STRONGYLUS CONTORTUS, Rud. 


PLATE XVIII. 


Adult female, x6: a, head; b, ovaries wound around the intestines; ¢, ¢, 
uteri; d, a large papillie, just in front of and covering the vulva; e, anus. 

Adult male, x6. 

Head: a, two barb-like papilla ; 6, mouth; c, esophagus ; d, intestine. 

Eggs, highly magnified: a, eggs before they have left the ovaries; b, eggs 
showing nuclei; c, eggs after they have passed through the oviduct; d, 
egg with one cell; e, with two; f, with four; g, with eight; h, with 
many; 7, egg as it is laid. 

Skin, showing nine of the eighteen longitudinal lines. 

Portion of female: a, the intestine; b, b, the ends of the ovaries. 

Caudal end of female: a, the anus; b, the vulva; c, vagina; d, d, uteri 
filled with eggs; e, oviduct; f, f, ovary; g, intestine. 

Spicula, enlarged. 

Bursa, expanded to show costie: a, ventral; b, ventro-lateral; c¢, lateral; d, 
dorso-lateral ; e, dorsal ; f, spicula. 


10.G roup of adult males and females, natural size. 


Fig. 11. Caudal end of male: a, bursa; 6, spicula; c, seminalreservoir; d, iatestine. 


PLATE XVIII : 


pont 5 < 
os RT TENT = 


Adfoen & Co. Lith. Bulhrtore, 


STRONGYLUS CONTORTUS, 
(Tne Twisted Stomach Worm.) 


v a ioe L(G 
: _ aes 
ws ' 
Pe . 
¥ =< : 
| P : . 7 
7 : 
| . 
e 
: = 
-_ _ < 
° ¥ 
: e 
=“ j é - 
* 


7 7 ; F ee | 


INTESTINAL ROUND WORMS. 


Sheep in this country harbor at least six species of round worms, 
parasitic in the small and large intestines, which their ancestors brought 
with them from Europe. They are: Strongylus filicollis, Rud.; Strongy- 
lus ventricosus, Kud., both found in the duodenum ; Dochmius cernuus, 
Creplin, found in the small intestine ; Ascaris lumbricoides, Linn., also 
found in the small intestine; Trichocephalus affinis, Rud., found in the 
cecum ; Sclerostoma hypostomum, Diesing, found in the large intestine. 
A seventh species, Gsophagostoma Columbianum, Curtice, is found in 
the large intestine and is probably indigenous to this country. Of all 
these the last species produces by far the most injury. Dochmius cer- 
nuus is next in importance. The injury inflicted by the others may, at 
times, and in conjunction with other parasites, be considerable ; but 
disease which may be ascribed to either species alone has not yet been 
reported. From personal observations it is believed that the number 
of individuals in each sheep are usually too few to ever cause extensive 
loss, and that their greatest harm is from the little discomforts which 
they may add to those produced by the more destructive parasites. 

At certain seasons of the year some of the above species are abun- 
dant, while at other times but few individuals may be found. Strongy- 
lus filicollis and S. ventricosus are usually found associated together, but 
are so Small that they can easily be overlooked, or if found may be re- 
garded as the young of other species. Dochmius cernuus is about an 
jnch long, and being large is readily detected. Ascaris lumbricoides is 
rare, having been met with only a few times by helminthologists in any 
country, and in but one lot of sheep by the author. Trichocephalus 
affinis is usually found in young sheep, but is met with in comparatively 
small numbers. Sclerostoma hypostomum seems to be a rare species in 
the East, the single instance in which it was met with in these investi- 
gations being in examining an old sheep in Colorado. Csophagostoma 
‘Columbianum seems to take the place of the last-named species in the 
Kast, and is found most abundantly in spring and summer in its adult 
State, although it is present throughout the year. The most favorable 
time for collecting most of these species has been in late fall and win- 
ter. The quantities in which the various species may be found vary 
with the season and the flock examined, so much so that no accurate 
statements of percentage of occurrence or of distribution can be made. 

The symptoms which these worms produce are those of general debil- 

23038 A P——10 145 


146 


ity and indigestion. They Are caused by the irritations set up in the 
intestines by the worms. It is found as a rule that a weakly sheep is 
attacked by more than one species of parasite at a time, and, conse- 
quently, it is difficult to learn the symptoms produced by either of them 
acting alone. Then, too, it should be remembered that symptoms are 
sometimes incorrectly attributed to parasites when they really result 
from diseases due to entirely different causes. Even the fattest sheep 
harbor a few parasites, and some of them many more than one would 
suspect from their apparent good health. 

The treatment should be directed toward keeping animals in ie 
health and in preventing them from acquiring parasites by providing 
them with pure water and pastures which are not overstocked. Medic- 
inal treatment will rarely be attempted for any single species of these 
parasites. A remedy which wouid prove effective for any one of them 
would do for all. Their treatment will therefore be embraced under 
that for Dochmius cernuus. 


STRONGYLUS FILICOLLIS, Rud. 
Plate XIX. 


Description.—Male, 8 to15™™; female, 16 to 24™™, Body very small; cephalic end 
thread-like and tortuous ; canal end, especially of female, thick and straight. Skin 
marked by longitudinal lines standing at about equal distances apart. Head very 
small, subspherical, continuous, with a swollen cylindrical neck; the length of the 
inflated portion is about one-fourth that of the esophagus. Four head papille visi- 
ble; the lateral papille are probably present, but can not easily be made out. Mouth 
terminal; apparently without chitinous armature. QMesophagus linear spatulate ; 
unicellular gland ducts present. . Position of ventral cleft not determined. 

Male: Filiform and uniform in size throughout itslength; bursa strongly bilobed ; 
the membrane being well filled on the dorsum but absent on the ventrum ; can not 
be spread without tearing; cost generally symmetrically arranged, ventral slightly 
separated; ventro-lateral either joined to lateral or ventral; lateral scarcely sepa- 
rated; dorso-lateral joined to the dorsal, dorsal notched and with the dorso-lateral 
form a stem, the two pairs uniting to form the dorsal stem; the lateral cost are the 
jongest. Spicula 1.5™™ long, cylindrical, very slender and dark colored; their 
points are tipped with an oval inflation of the membrane and are more or less firmly 
attached. 

Female: Tail obtuse; vulva situated about one-third of the entire length of the 
worm from the tail; body of the egg-bearing female enlarged in front of the vulva 
by the swollen and crowded uterus, Uteri directed each way from the vagina, and 
filled with comparatively few and large eggs in all stages of segmentation. Eggs 
0.17"™ long, 0.08™™ wide, ovoid ; laid in the morula or gastrula stages. Embryo not 
observed. 


This species occurs with Strongylus ventricosus in the upper end of 
the small intestine of sheep and lambs. It is often mistaken for the 
young of other species, and has been identified as a variety of Strongylus 
contortus. It is needless to observe that it is specifically different from 
any other nematode found in sheep; a glance at the plate illustrating 
the species is sufficient proof of this. It is quite abundant during fall 


147 


and winter. European observers seem to find it rather infrequently. 
The species appears to be a comparatively harmless one. It is probably 
the young of this species which Wedl found associated with Tania 
expansa, and named Trichosoma papillosum. Wedl characterized it as 
having a double uterus and the mouth furnished with four papille. 
Neither of these characters is inconsistent with Strongylus filicollis, 
while the fact that Wedl’s species, with a double uterus, was classified 
in a genus which has a single uterus and spicule indicates an error. 


148 


STRONGYLUS FILICOLLIS, Rud. 


Le GUT DUDS 


Adult male, natural length indicated byline: a, head; b, bursa and spicula; 
c, worm enlarged twice. 

Adult female, natural length indicated by line: a, head; b, vulva; c, anus; 
d, worm enlarged twice. 

Head: a, mouth surrounded by four papill ; b, esophagus; c¢, inflated skin 
surrounding head and neck. 

Skin: shows nine of the eighteen longitudinal lines. 

Cephalic end: a, the head; 6, the cwsophagus; ¢,c, the unicellular gland 
ducts. 

Bursa: a, the spicula; 6, their knobbed tips. 

Portion of the spicula enlarged, 

Ovary of female with inclosed eggs showing segmentation. 

Bursa spread ont: «a, ventral cost ; b, ventro-lateral; c¢, lateral; d, dorSo- 
lateral; e, dorsal. 


PLATE XIX 


A. Hoen & Co. lath. Baltiinore. 


STRONGYLUS FILICOLLIS 
(The Thread-Necked Worm.) 


149 


STRONGYLUS VENTRICOSUS, Rud. 


Plate XX. 


Description.—Male, 6™™; female, 13™™, Body very small and comparatively stout. 
Males and young females usually spirally coiled; body of old female straight, with 
cephalic end coiled, Skin transversely striate, marked by fourteen longitudinal 
lines; the five larger standing at equal interspaces on the dorsal and ventral sur- 
faces, the two smaller standing close together on the sides. The crossings of the 
strive and longitudinal lines make pits which are quite characteristic. Head little 
larger than neck, but hemispherical and continuous with the cylindrical inflation of 
the neck. No head or neck papillie visible. Mouth terminal, very small and round. 
The end of the head is furnished with a hemispherical cap-shaped chitinous piece. 
Other oral armature apparently absent. Inflated portion of head about one-fifth the 
length of esophagus. Unicellular glands not apparent. Male about one-half the 
jength of female; bursa conical and bilobed, the ventral membrane being narrow, 
the dorsal wide; ventral cost not separate, smaller than the ventro-lateral, which 
is stout; lateral widely separate and apparently formed of three nearly equal costie ; 
dorso-lateral slender; dorsal notched at the end and giving off laterally a very short 
side branch. Spicula 0.36™™ long, short and stout, and margined by a fringe-bearing 
sinuous membrane. They are tipped by a soft pad-like expansion of the membrane. 
Female characterized by a swelling at the vulva, which gives the species its name. 
This character is more pronounced in older specimens. Vulva from two-ninths to 
one-third of the entire length of the female from the tail. Uteri directed anteriorly 
and posteriorly from the vagina. Ova 0.13™™ long, 0.07™™ wide, comparatively 
large, and found in all stages of segmentation. Embryo not obsérved. 


This species is found in association with Strongylus filicollis in the 
upper part of the small intestine of sheep. It can be separated by its 
smaller size, its spiral twist, and the markings of the skin. It is best 
found in fall and winter. The species was originally described from 
specimens taken from cattle, and so far as known has never before 
been noticed as being found in sheep. The female in its adult stage re- 
sembles the small specimens of S. filicollis. It is apparently the cause 
of little or no disturbance, although from the appearance of its mouth 
parts it might seem to be more injurious than S. filicollis. 


io) 


150 


STRONGYLUS VENTRICOSUS, Rud. 


PLATE XX. 


Male, natural size indicated by line and small figure of worm: a, head ; 3b, 
bursa and spicula. 

Female, natural size indicated by line and small figure of worm: a, head; 
b, genital orifice. 

Head: a, mouth; bb, chitinous cap surrounding it; ¢, esophagus. 


. Portion of skin showing eight of the fourteen lines: a a, the two lateral 


lines; b b, the dorsal and ventral lines. The dots indicate depressions 
where the longitudinal and the latitudinal lines cross. 

Cephalic end: a, head; b, esophagus. 

Spiculum: a, its ehitinous portion; b, the protractor muscle; ec, the fringe 
edging the membranous portion; d, the distal end covered by membrane, 

Female, natural size indicated by line: This female is more characteristic of 
the species than that of Fig. 2, but is not quite mature. 

Bursa with spicala. 

Bursa spread out: a, ventral costie; b, ventro-lateral; c, lateral, of which 
there seems to be an accessory branch; d, dorsal-lateral; e, dorsal, which 
also has an accessory branch. 


. 


PLATE XX 


A.Hoen & Co, Lith, Baltimore. 


STRONGYLUS VENTRICOSUS 


(The Ventricose Worm.) 


THE LARGE ROUND WORM. 
ASCARIS LUMBRICOIDES, Linn. 


Plate XXI. 


Description.—Male and female 150™™ each ; in the specimens figured 120 each. Body 
very large and thick, obtuse at each ead, of a yellowish color, skin marked by rings. 
The site of the vulva is marked by a smooth wide band about one-third the entire 
length from the head. There are three longitudinal bands; the two wider are nearly 
lateral; the third is ventral. The head end is abruptly terminated in three well- 
formed lips; the dorsal possesses two papill# near its base and the two ventral one 
each. Each lip consists of a chitinous support covered by cuticular membrane. The 
tail of each is obtuse. The description after Schneider (Monographie d. Nematoden, 
p. 36) is as follows: 

‘Lips nearly equal, their form changing from semi-circular to quadrangular. Teeth 
very fine. The lobes undivided. The azygos lobe has a rounded point, and reaches 
with its anterior end to the front of the saddle. Cuticularrings longitudinally ribbed, 
Vulva 40 to 65™™ from the cephalicend. Vagina 11"™ Jong. Tail of the male flat om 
the ventral side. Only behind the anusis the skin broadened into a bursa; sixty-nine 
to seventy-five papille on each side; the first seven pairs of these papille stand behind 
the anus; the second pair stand nearer the ventral line than the first and third; the 
fourth and fifth pairs and the sixth and seventh pairs are united into double papille. 
(See Fig. 7.) The succeeding stand first in a single row, then in pairs forming a 
double row; and on the whole they are very irregular. An unpaired papille stands 
in front of the anus. Spicula two, each a single tube, with its point terminating 
bluntly and irregularly in front. 

“This parasite occurs in the small intestine in man and swine, and sometimes 
forces its way into the gall ducts, stomach, esophagus, nose, and lungs.” 


In one flock of sheep only has the author found this parasite. In this 
flock it occurred in six animals, a majority of those examined. That it 
is not a common parasite is attested by the writings of various Euro- 
pean helminthologists. A few of the latter have described a special 
species (Ascaris ovis), from the sheep, but as it is infrequently found it 
seems to be an inconstant parasite or an adventitious one, 7. ¢., it is 
probabiy a constant parasite of some other domesticated animal, and 
occasionaily only becomes parasitic on sheep. Besides, the specimens 
figured always seem to have been immature, and do not differ from 
Ascaris lumbricoides of the same size and age. 

In the single flock in which this worm was observed all the specimens 
found were immature. The vegetative organs of these specimens differ 
in no essential point from those of Ascaris lumbricoides as figured by 
various authorities. In addition, a close comparison of these specimens 


151 


152 


with equally immature Ascaris taken from pigs gave no determinable 
differences. These remarks presuppose that A. lumbricoides of man 
and A. suilla of swine are identical species. The description seems to 
be incomplete, but as the species is neither peculiar to nor commonly 
found in sheep no attempt is made here to enlarge it. The species can 
easily be determined by a comparison with the figures. 

Sheep probably acquire this parasite while pasturing after swine. 
As few are infected, little harm is accomplished by the Ascaris. It is 
more abundant in summer and fall than at other seasons. 


NF, a : are 


Pe Avad 


uti daria colli hi 
“ eet Hiab yoann pubs ‘ a: 
e. Pal per boll ve é tebe ithe =) Leadtidare Phd ye Oty Ture 
meee bite) cand Diy ip 
ee Opn) 4 gly | ne kadtd +n 
: : oy a riled Meal: aha 
stelitgeg os ie ioe (ned iia Reese alive) Pp BF FF nl 4 
; ; yr Lisle Tasiie) i ee ; 
ie Te i we Oe, Ye oli Ve Ligh at Ati 
yen = . tal fhireil oi it 5; (iathedv fig Pai Ae hapa \o 
J ee ell Bes bin ye ar ue eet “are 
. SUN DIC Loner ey 1h ie 


| ri Puhr dal olain ts Me tit. Ob ae 
. » MY bare \aitldin if ut 


Fig. 4 
Vig. 5 
Tig. 6 
Fig. 7 
Fie. 8 
Fig. 9 


154 


ASCARIS LUMBRICOIDES, Linn. 


PLATE XXI. 


. Adult male, natural size. 
. Adult female, natural size. 
. Top view of head enlarged; a, dorsal lip with two papille; b, b, ventral 


lips with one papille each. 


. Head, ventral view. 
. Head, dorsal view. 
. The lips greatly enlarged and flattened: a,a, papille; b,b, the serrated 


edge of chitinous support. 


. Tail of male, ventral viéw: a, anus; 1, 2, 3,4 and 5, 6 and 7, the post- 


anal papillie; 8, the unpaired pre-anal; 9, 9,9, other papille. 


8. The two spatulate spicula: 8a, one of these enlarged. 
. Portion of female: a, the genital opening; b, the ventral line; c, one of the 


two lateral lines. 


. Tail of female, lateral view. 
. The same, ventral view. 


PLATE XXI 


. Baltiinore. 


A. Hoen & Co, lath 


ASCARIS LUMBRICOIDES, 
(The Common Round Worm.) 


reo 


155 


DOCHMIUS CERNUUS, Creplin. 
Plate XXII. 


Description.—Female, 20 to 26™™; male, 13 to17™™. Body very dark colored when 
fresh ; whitened when preserved; attenuate towards the ends. Head curved, the 
mouth being directed dorsally. Mouth round, smaller than the oral surface, and 
opens into an ovoid dark-colored capsule. Abont the opening stand four teeth, two 
on each side, their base being sunk into the capsule and their free edges projecting 
into the cavity. The ventral are the larger, thicker,and more opaque; their edges 
form an unbroken sinnous line. At the caudal opening of the capsule are one pair of 
ventral and a single dorsal tooth; the latter is conical, very large, and risss to near 
the mouth. In the pharyngeal opening are six very small elub-shaped, spinous, 
chitinous appendages of the cesophageal supports or rods; they seem to be jointed. 
There are six papille—dorsal, lateral, and ventral pairs. The lateral may give off 
a branch on the dorsal side. There are two lateral neck papillie, nearly opposite the 
middle of the esophagus; the ventral cleft is situated a little anterior to a line con- 
necting the latter. Unicellular neck glands quite plain. 

Male: Bursa fannel-shaped ; will not spread without tearing ; cost unsymmetrical 
as to form; ventral pair not separated ; lateral, widely separated; dorsal notched; 
dorso-lateral unequal in length and differently attached to the dorsal stem. Spicula 
0.6™™ long, aculeate, fenestrated, and provided with a narrow membranous margin. 

Female: Vulva about three-fifths of the entire length of the body from the end of 
the tail. Vagina opening at right angles to the side of the body. Uteri, lying one 
anterior, the other posterior; each forms an §-like loop; the anterior ovary is di- 
rected towards the tail, and, with the posterior, forms an intricate sinuous net-work 
surrounding the intestine. Eggs elliptical; laidin the morula stage; length, 0.06™™; 
width, 0.03™™. ; 


Occurrence.—This species inhabits the small intestine of sheep, and 
attaches itself to the intestinal walls by its stout oral armature—the 
so-called teeth. It lives upon the blood of its victims. 

The life history of this species of Dochmius las not been determined, 
but there is no reason for supposing it different from that of D. trigo- 
nocephalus, the allied species found in dogs. This life history has been 
determined by Leuckart (Die Menschlichen Parasiten, Band II, pp. i32- 
154), and is essentially this: The eggs pass from the dog to the ground, 
where, in wet places, they undergo a development of the vegetative 
organs. If at this stage the young are swallowed by another dog they 
develop into adults. The development outside the dog may consume 
from three to six days. The worm may then continue living without 
further development for an indefinite time, depending on the conditions 
by which it is surrounded and the favorable opportunities for being 
eaten by the dog. Its development in the dog occupies about two 
weeks. The time consumed may be supposed to be that occupied by 
the development of Dochmius cernuus with approximate certainty. 
Leuckart states that though he saw some of the embryos enter snails 
while in their free living state, that this condition was an unnecessary 
one, and that the worms underwent no development while in the snails. 
It may be that if these parasites can enter the snails, their opportuni. 


156 


ties for safely passing the indefinite time prior to finding their way into 
their final host are increased. 

In my own experiments in keeping a number of lambs in a cireum- 
scribed space for five or six months after purchase, and in confining two 
others raised there with them, allowing them no water save such as 
was pumped for them, Dochmius cernuus were found of various sizes in 
the lambs of each set. The two lambs raised on the place must neces- 
sarily have acquired them there. These parasites either developed to 
a certain extent in the iron watering trough or in little pools which 
could have collected and remained in the yard for a day or two after a 
rain, or the lambs were infected from the dry hill-side of the inclosure. 

The disease can only be diagnosed by the flock-master from a post- 
mortem examination. It has been recommended to diagnose these para- 
sitic diseases from the eggs of the worm found in examining the feces 
by the aid of a compound microscope. Such a plan is very tedious in 
its execution, and impractical save to one already skilled in the work. 

The disease caused by Dochmius cernuus receives little attention in 
veterinary works. This is due, in all likelihood, to the fact that not 
more than two or three hundred of the parasites ever seem to be pres- 
ent in one sheep, and generally there are less than one hundred; then, 
too, if other parasites are found present the illness would probably be 
ascribed to them. If, however, we may be allowed to infer the effects 
which would be caused in sheep from the effects which Dochmius 
duodenalis, a related species, produces in man,* in whom it has caused 
epidemics characterized by progressive anzmia, and if we may accu- 
mulate corroborative evidence from the disease which Dochmius trigo- 
nocephalus, a third species, produces in dogs, we may fairly infer that 
the species causes more disease than has been suspected. Nor is its 
comparative paucity in individuals any contra-evidence, for in human 
patients affected with this disease the species is represented by usu- 
ally less than a hundred specimens, although as high as two or three 
hundred have been found in one patient. In dogs the author has 
found about the same number. 

The intestinal lesions are obscure to the unaided eye, except at those 
points where the parasites have been attached. Here, if the worm has 
recently loosened its hold, there is a slight blood extravasation. The 
parasites maintain their hold by the chitinous cup with its projecting 
oral teeth, and in some way cause a hemorrhage, upon which they feed. 
The six pharyngeal spinose appendages may aid in wounding the deli- 
cate epithelial cells. 

It seems impossible that a dozen or twenty, or even fifty, specimens 
of Dochmius could, by creating such little injuries in withdrawing blood 


*Literature: Wilhelm Schulthess, Zeitschrift f. wiss. Zoologie, XXX VII, 1882, pp. 163- 
217. J. Ernst, Deutsche med. Wochenschrift, 1388, p. 291. <A. Friinkel, ibidem, 1885, p. 
443. O. Leichtenstern, ibidem, 1885, pp. 484, 486, 501, 523; 1886, pp. 173, 176, 194, 216; 
1837, 565 and five following numbers; 1888, p. 848. 


157 


from its host, cause the severe disease and progressive anemia ascribed 
to it in man, but such has been determined to be the fact from clinical 
and post-mortem observations. It may be that there is a reflex, sympa- 
thetic action stimulated by them of which we can take no account. 
The further changes observed in patients affected with Dochmius are 
much the same asin those affected with other parasites, except that 
anemia with its attendant effects seems to be the most prominent. 

The disease is one which begins in early lambhood and progressively 
continues, the severity depending on the number of parasites entering 
the intestinal canal. The adult probably lasts through the winter and 
continually lays eggs which pass to the ground. The character of the 
season, of pasturage, and of the water, in being either favorable or 
unfavorable to the preservation of the young worms while on the ground, 
will therefore determine the amount of infection and sickness during 
the following season. 

The preventive treatment for the intestinal worms is the same as that 
advised for the lung worms—good care, pure water, plenty of grass, 
sufficient grain feeding, salt, aud separation of sick from the well. For 
the reason that the disease has not received the attention its impor- 
tance demands the medicinal treatment has not been worked out with 
the thoroughness that some of the other parasitic diseases have re- 
ceived. 

Medical treatment.—In man the most effective remedy is extract of 
male fern, combined with powdered male fern, the remedy to be pre- 
ceded five or six hours by a dose of castor oil. This combination is also 
a good one to administer to dogs in the following proportions: Extract 
male fern, 40 grains; powdered root of male fern, 75 grains. *This mass 
must be made into ten pills with yellow wax, and all given at once. 
The dose of powder of male-fern root for sheep is from 13 to 3 ounces, 
and of the extract from 2 to 4 drams. As boluses are not only incon- 
venient to give to sheep, and do not pass directly into the fourth 
stomach, the administration should be by drenching. I should advise 
that the extract be mixed with from 2 to 4 ounces of castor oil. Other 
remedies advised for the round worms are wormseed, wormwood, and 
santonine. The latter is an alkaloid obtained from a species of Ar- 
temisia. As the prairie lambs love to eat sage, of which there are a 
number of species belonging to the genus artemisia, it is likely that 
‘ these plants may prove beneficial to them through medicinal qualities. 
In my examinations of Western prairie sheep I do not now recollect hav- 
ing met with as many round worms as are found in Eastern sheep. ‘The 
dose of santonine for sheep is from 1 to 3 grains, given in from 2 to 4 
ounces castor oil. The preparations of tansy, Tanacetum vulgare, have 
long been used as vermicides. The dose of the oil is from 1 to 2 drams, 
given diluted by adding from 4 to 8 ounces of another oil. The receipt 
for Spinola’s worm cake sufficient for one hundred sheep is: Take of 


158 


tansy root, calamus root, and tar, of each 25 pounds, of common salt 
14 pounds, make into cakes with meal and water, and dry. The dose 
of areca-nut powder, which is an effective reniedy for round worms as 
well as tape-worms, is from 1 to 3 drams for lambs. 

The oil of turpentine has proven of itself a valuable anthelmintic, but 
should be used with care. For intestinal round worms in sheep from 1 
to4 fluid drams may be given, according toage. Theturpentine should 
be mixed with from 2 to 4 ounces of castor oil. Sweet or linseed oil 
may be substituted, but their cathartic effects are untrustworthy. More 
than one dose should not be given until two or three days have elapsed, 
when, if it is deemed advisable to give a second dose, no untoward re- 
sults having been noticed from the first, the dose, slightly increased, may 
be repeated. Do not give more than the maximum dose. Tellor (Dis- 
eases of Live Stock) gives the following recipe: Linseed oil 2 ounces, 
oil of turpentine one-half ounce, for a drench. The French veterinari- 
ans advise, among other remedies, the use of empyreumatic oil, petro- 
leum, and chimney soot. Empyreumatic oil is animal oil, a by-product 
of distillation of animal matter for ammonia. Dippel’s ethereal extract 
is arefined product, and the oil of Chabert consists of animal oil 1 part, 
turpentine 3 parts. The medicine should be administered as a liquid. 
The dose of animal oil, or oil of Chabert, is from 1 to 2 drams, to be 
given in 4 ounces of the chosen vehicle. The oils and alcohol dissolve 
animal oil, but if the vehicle is a watery mixture it must be well 
shaken. Bitter vermifuges made up into tea are excellent, as is also a 
decoction of chimney soot thickened by dextrine or the yellow of eggs. 
From the certain effect that petroleum has on insects externally we may 
infer that it should prove a valuable anthelmintic internally, if it may be 
given in sufficiently large doses. It has been used in man for tenia 
and round worms. The dose is 30 minims. The dose for sheep may be 
as large; how much larger future experiments will determine. Until 
the toxic dose is learned it should be given with caution. Itis proba- 
ble that 2 dram doses may be used. Give with from 2 to 4 ounces of 
sweet, linseed, or castor oil. 

Besides these there are many other remedies proposed, as savin, 
sabadilla, spigelia or pink root, aloes, tartar emetic, asafetida, azeda- 
rach, kousso, kamala, and pumpkin seed. ‘The greater part are of 
doubtful efficacy; others are dear, and can be replaced by remedies 
equally as good and cheaper. Many of the bitter herbs may be pow- 
dered and given with grain, but the sheep will not get enough to have 

the besteffects. Often the worst-affected lamb will not eat any, or very 
little, on account of loss of appetite. This method of administration is, 
besides, wasteful. The uncertainty of sheep receiving a full dose is the 
chief argument against such a method. The effect of some of these 
plants on sheep is also modified by the fact that sheep are plant eaters 
and become more or less accustomed to the various medicinal principles 
found in them. 


2 0g 


0g. 


DOCHMIUS CERNUUS, Creplin. 


Pilate XXII. 


. Adult male, xX 9: la, natural size. 
. Adult female, X 9: 2a, natural size ; b, vulva. 
. Cephalic end of male, ventral view: a, head; b, b, esophagus; c, c, neck 


papilla; d, opposite ventral cleft out of which the unicellular gland 
ducts e,e, empty by a common tube, f; g, unicellular glands; h,h, two 
ends of the seminal tubes; 7,i,i,seminal tube; k, k, intestine. 


. Head, dorsal view: a, mouth; b,b, the chitinous oral teeth on the left side; 


c,c,¢, three papillw on right side; d, dorsal teeth; e,e,neck glands; f, 
cesophagus. 


. Head, right side. Letters as in Fig. 4: g, ventral teeth; h, chitinous 


capsule. 


. Pharynx and lower part of capsule of head, ventral view: a, the cut edge 


of capsule; b, the dorsal tooth; ¢,c, ventral teeth; d, pharynx, in which 
are six club-shaped bodies, which seem to. be appendages of the chiti- 
nous rods of the @sophagus; e, esophagus; f, enlarged club-shaped 
body, which is chitinous and covered with rough points. This apparatus 
seems to be for mastication. 


. Middle portion of feinale, x30: a, vulva; b, vagina; ¢,c, portions of cephalic 


uterus; d, d, caudal uterus with eggs; e, oviduct ; f, f, cephalic ovary ; 9, 9, 
caudal ovary; h,h, intestine. 


. Eggs: a,a,from ovary; b, in oviduct; the rest from the uterus in various 


stages of cell division; ¢, as they are expelled. 


. Bursa: a, ventral costw#; b, ventro-lateral; c, lateral; d, latero-dorsal ; e, 


dorsal. The two sides are unsymmetrical. 


. Spicula. 
. Portion of spiculum showing fenestrations and openings into the tube: a, 


tube; b, wing. 


PLATE XXII 


par 


pera) 


Tyee 


PESTS 


rede} Resi: 


A.Hoen & Co. lit. Bolnmore 


DOCHMIUS CERNUUS, 
(The Bent-head Round Worm.) 


161 


SCLEROSTOMA HYPOSTOMUM, Dujardin. 
Plate XXIII. 


Description.—Male, 16™™; female, 24™™, Body white, cylindrical, and stout. Head, 
globular, a little ventrally curved and truncate at the mouth; head papille six; 
neck papillee not observed; ventral cleft about opposite the end of the second fifth 
of the esophagus, counting from the head. Unicellular glands and lateral lines very 
conspicuous. Mouth-opening round, obliquely inclined; surrounded by a single 
circle of very minute saw-like teeth. The globular chitinons capsule is marked by 
numerous longitudinal elevations, which are stronger at its bottom, The posterior 
opening is circular, unarmed, but roughened. Around the mouth is a circular canal 
which empties into a dorsal canal. ‘There is apparently no pharyngeal apparatus as 
in Dochmins. Csophagus slightly swollen caudally. Two lateral ducts opening near 
the mouth and situated on either side’ of the head are apparent; they seem to end 
caudally in the lateral canals. Male about two-thirds the length of the female. 
Bursa shallow, set on obliquely, campanulate. Ventral cost# either separate or 
slightly so; lateral slightly separate if at all; dorsal pair irregular and widely sep- 
arate; the dorso-lateral and dorsal forms a single stem with three lateral branches. 
Spicula 1.5™™ long, linear aculeate, cross-striated, and bordered by narrow margins 
which roll in towards each other. Two anal papille. Female stout and thick, and 
usually with a brown crust near the vulva. Vulva very near the tail. Tail full to 
near the end, but ending in an acute mucronate point. Uteri directed toward the 
head; one, the caudal, makes a loop at the tail. The ovaries show loops near the 
tail. Eggs elliptical, 0.1™™ long, 0.06™™ bread, laid in the gastrula stage. Embryo 
not observed. 

Occurrence.—Sclerostoma hypostomum is found in the large intestine 
of ruminants. It is present associated with Csophagostoma Colum- 
bianum in sheep in this country, but not abundantly. It is closely re- 
lated to Sclerostoma equinum of horses, a species said to make tumors 
in the intestines. As S. hypostomum is rare, it has not yet been deter- 
mined whether it causes intestinal tumors in sheep. Since S. tetracan- 
thum, whose embryos make tumors in the caecum of the horse, is more 
nearly related generically to Qsophagostoma than to Sclerostoma, I am 
inclined to believe, as I have proven in regard to Gsophagostoma Colum- 
bianum in sheep, that the species belonging to the genus Gisophagostoma 
are intestinal—tumor-making parasites rather than those of Scleros- 
toma. 

Life history—M. Baillet (Nouveau Dict. de Med. T. VIII, art. Hel- 
minthes, 1886) is authority for the followimeg: 


The sclerostome of ruiminants is reproduced in the same way as that of solipeds. 
Its eges, of which the vite!lus is segmented in the uterus of the female, are laid in 
the large intestine and carried without by the fecal material. They are hatched after 


23058 A P—-11 


162 


a few days, and the embryos are very stmilar in their general form to those of Scleros- 
toma telracunthum, ‘They are cylindroid, subobtuse at the anterior extremity, and 
provided with a narrow tail much shorter than those of the youne sclerostomes of the 
horse. They move, besides, in the same manner as the latter. They can live a long 
time in the fecal material of raminants when they are not dried, and in this condition 
they grow. Some young Sclerostomes which, after hatching, were 0.35"" long to 
0.50 have been found in the droppingsof sheep. After having been kept damp two 
and a half months these were from 0.66 to 0.78"™ long. Their skin, which is folded 
on the surface of the body, appears to indicate that, like the Sclerostomes of the horse, 
they are prepared to undergo a molt. The young Sclerostoma hypostomum can live a 
long time in water after having reached a definite size in the fecal material of rumi- 
nants. ae. 

We have not yet observed cysts within the mucous membrane of the large intes- 
tine of sheep.* But as the Sclerostoma hypostomum are in far less numbers of 
ruminants than S. equinum or S. tetracanthum in the horse, we can not yet draw 
any conclusion from the negative result of our researches. We will not say then at 
present whether the Sclerostomes of ruminants pass the second phase of their exist- 
ence in cysts, or whether they are developed in the intestinal canal itself in the 
midst of alimentary material which is found contained there. The egys of the Scle- 
rostomes of ruminants taken directly from the uterus of females and preserved in 
water at a temperature of from 12 to 20° C. (about 55 to 70° Fah.) hateh at the end 
of four or five days after having undergone all the series of successive modifications 
which are alike observed in the eggs of Sclerostomes of solipeds. 

The only possibility of error in Baillet’s experiments is the indentifi- 
cation of the species with which he was dealing, for he writes: 

It (Selerostoma hypostomum) is above all very frequent in sheep. There are often 
found individuals, probably younger, whose mouth, entirety terminal, is less widely 
open, and provided with a single rank of teeth still less numerous. These worms 
also lack a pharyngeal capsule, and often carry a membranous swelling on the sides 
of the head. 

The above describes Gisophagostoma venulosum quite well, and when 
the learned helminthologist did not experiment with eggs taken directly 
from the adult worm he may have had to do with the eggs of either. 
This would account for the similarities found between some of the 
young embryos experimented with and those of Sclerostoma tetracan- 
thum. (The author is of the opinion that the last named species should 
be classed with the G?sophagostoma instead of the Sclerostoma.) 

The life history of this species is, that the eggs are scattered by the 
sheep, that they then develop somewhat, and without the need of any 
secondary host are capable of further development in sheep when taken 
by them along with the food or drink, and that in the large intestine of 
the latter they may or they may not make tumors during their embry- 
onic stages. 

The prevention and treatment is the same as for other intestinal 
WOYTIS. 


* This indicates that Q@sophagostoma Columbianum has not been observed in France,— 
C.C 


164 


SCLEROSTOMA HYPOSTOMUM. 
12a DOU 


1. Male, x8. Fig. la, natural size. 

Fig. 2. Female, x8. Fig. 2a, natural size. 

3. Head, penteal view: a, the capsule; b, the dorsal nae ; ¢c, lateral ducts; d, 

cesophagus. 

Fig. 4. Head, lateral view: a,c, d, asin Fig. 3; e, the three head-papille; f, the com- 
mon duct of the joined unicellular plana ducts is placed near the ventral 
cleft; g, the end of the w@sophagus, showing three dependent lips; h, the 
eut-end of the skin. The drawing shows the longitudinal muscular band, 
separated into two groups by the lateral canals, i, i, and the three separa- 
tions of the muscular bundles between these canals which appear on the 
surface as lines: k, k, k, cut end of the intestine. 

Head, dorsal view: a, b, c, and das in Fig. 3. 

Mouth end of Jateral half of chitinous capsule: a, a, a, the ventral, laterai, 
and dorsal head papillie; b, the dorsal canal which continues around the 
head in c, c; d, the mouth, around which is a circle of small thorn-like 
teeth, about forty in all. 

Fig. 6a. Teeth enlarged. : 

Fig. 7. Caudal end of capsule: a, the cut wall; b, the dorsal canal; e, the triangu- 

lar opening of cesophagus. 

Fig. 8. Section of esophagus: a, a, a, the chxbinious support; b, b, b, the walls, e, 

the orifice. 

Fig. 9. Male bursa with spicula. 

Fig. 9a. Portion of spicule: a, the chitinous cylinders; b, the membranous margins. 

Fig. 9b. Diagram of anal papillie. 

Fig. 10. Bursa spread out: a, ventral costie; b, lateral; c, dorsal; d, the torn edge. 

Fig. 11. Caudai end of female: a, anus; b, vulva; ec, c, uteri; d, d, loops of the 

ovaries; e, e, the intestine; f/, a dark brown patch usually found on the 
vulva; g, an egg. 

Fig. 12. Cross-section of female: a, intestine; b, ovaries; ¢, lateral ducts; d, muscu- 

lar bundles (Leuckart). 

Figs. 3, 4, 5, and 6 are somewhat distorted by flattening. 


~ 
. 


. = 
Fig. & 


Vig. 


7 


3 


PLATE XXIII 


my, 
“<S = Sa 


A.Hoen & Co, Lith. Boltimore. 


SCLEROSTOMA HYPOSTOMUM 


THE NODULAR DISEASE OF THE INTESTINES. 
CESOPHAGOSTOMA COLUMBIANUM, Curtice. 
Plates XXIV, XXV, XXVI, XXVII. 


In the Eastern States there exists a hitherto undescribed disease, 
whichis characterized by tumors present in the upper part of the large 
intestine. The disease causes heavy losses, for it seriously affects the 
health of the sheep, and renders the intestine valueless for making 
sausage casings. Though the latter result would seem trivial at first 
sight, it is by no means unimportant, for sausage-makers are compelled 
to import the greater part of covering material used in their business. 
The disturbances of health produced are very serious, for there are places 
in the South where sheep can not be kept with profit, apparently on ac- 
count of this parasite alone. Dr. D. E. Salmon, Chief of the Bureau of 
Animal Industry, who at one time lived in the South, performed many 
post-mortem examinations on diseased sheep, and found nothing but these 
intestinal tumors to account for the severe symptoms of disease which 
they exhibited, and has verbally stated that he believes this malady is 
the chief obstacle to successful sheep husbandry in some portions of the 
Southern States. 

Investigation.—The cause of the disease remained until the winter of 
1888-59 in obscurity, but owing to a favorable combination of materiai 
and methods of investigation it was then ascertained. Some of the 
larger soft tumors, which are characteristic of this disease, were dis- 
sected from the intestine, and after being slit open their greenish, 
cheesy contents escaped in a watch-glass of water. By carefully teas- 
ing the apparently newer portion of these masses a little worm, the 
cause of the trouble, was found. Previous to that time Dr. Theobald 
Smith, of this Bureau, had in the winter of 188687 made and examined 
micrescopic sections of these tumors. One of a series of sections (see 
Plate XXV, Fig. 8) showed what was apparently the fragment of a 
worm. Numerous other sections made at the same time showed no 
signs of this parasite, and the investigations were temporarily aban- 
doned. . 

Although tuberculosis is an uncommon disease in sheep, and although 
the tumors found in this disease differ in many essential points in both 
their history of formation and in their histological detail from those 
caused by tubercle bacilli, there was a superficial resemblafice, om 

165 


166 


account of which Dr. Smith made many tests of the easeous matter for 
the bacilli both by the microscopical methods and by the inoculation of 
small animals. In the light of subsequent investigations it is needless 
to say that these tests had only negative results. In justice to Dr. 
Smith it should be stated that he undertook the experiments more for 
negative evidence than from any expectation of finding bacilli. 

The cause of the disease is a nematode or round worm, which, though 
remarkably similar to some other worms of its group, is nevertheless a 
distinct species from any hitherto described. The failure to find this 
worm in our earliest investigations may be ascribed to two important 
factors. The first is that of the season of observation. We had proba- 
bly overlookgd those tumors which were best adapted to show the worms, 
but mainly on account of the season in which the examination was made. 
The method of examination was probably the greatest factor in the in- 
vestigation, for as soon as what may be termed macroscopic superseded 
microscopic methods the discovery was easy. The method was not en- 
tirely macroscopic, for simple lenses of low power were used. 

The worms found in the largest tumors were never over 3 or 4™™" 
in length, and presented only an embryonic development, the vegetative 
organs alone being present. Figs. 1, 2, and 4, in Plate XXV, were 
made from the largest specimens. As the adult worms of this class 
may differ materially from the embryos in the character of the mouth 
parts and in their appearance after the reproductive organs have de- 
veloped, the difficulty was encountered of connecting the embryonic 
cystic form with an adult form existing in sheep or elsewhere. 

Determination of adult—The most conclusive method of determining 
the adult would be to directly develop an embryo into an adult, but 
this proceeding was not attempted on account of its difficulties. A less 
satisfactory method remained of finding some adult worm whose em- 
bryo was unknown, and which not only corresponded in structure with 
the embryo, but whose life history was such that it was possible for it 
to be the parent of the embryo. It will not be profitable to detail 
theories advanced to aid in this investigation; suffice it to say that 
while studying one day a group of worms which came from the large 
intestines of sheep, I found among them an undescribed species. 

This species was immediately referred to the Sclerostomine (Raillet, 
Hlements of Zoologie, p. 330), and later to Molin’s genus Misophagos- 
toma. There may be an impropriety in accepting this name over others 
proposed at the same time for species of this genus, but as the same 
author proposed them, and as the genus is in general use, it is accepted 
in this classification. For reasons assigned hereafter in a description 
of the species I have called it a new one—(isophagostoma Columbianum. 
The specific name is from the fact that the worm was first found in the 
District of Columbia. 

The adult worm is found in the large intestine of sheep in considera- 
ble numbers, and in the same animal may also be found the tumors. 


167 


The parasite is usually found below the narrowing of the large intestine, 
where the latter changes from a sack-like receptacle to a large tube, 
and below the mass of the tumors. The tumors may, however, extend 
the entire length of the intestine. It is evident that the distribution of 
the eggs of this adult would be favorable for sheep becoming again in- 
fected by them. 

The oral armature of the embryo from the tumors and the adult (/so- 
phagostoma Columbianum differ, that of the embryo appearing to be like a 
chitinous cup comparable to that found in the young of the Sclerostoma 
of sheep and the Dochmius of dogs. The young of these species, however, 
differ as much from their adult form as the embryo in question does 
from its supposed adult form. 

The anatomical point that the writer considers of the most moment is 
that the embryos of the tumors possess a lapel-like fold on the ventral side 
of the worm just anterior to the ventral cleft, the opening of the unicellu- 
lar gland duct, and that the adult O. Columbianum possesses a similar 
fold identically situated. (See Plate XIV, Figs.1, 2, and 3, and Plate 
XXV, Figs. 2 and 3.) The absence of this feature in the embryos of 
Sclerostoma and Dochmius that infest sheep at once precludes the possi- 
bility that we have to deal with these species. That embryos of this 
character and corresponding adults are found in the same sheep makes 
the diagnosis more assured. Should we look for a host in some other 
animal we should expect to find one that had all the opprtunities of 
spreading the eggs that infect the sheep, but amongst our farm animals 
we find no corresponding parasite, and other wild animals which might 
be suspected as hosts are at the present time very rare. 


CHSOPHAGOSTOMA COLUMBIANUM, 0. sp. 


Description.—Male, 12 to 15™™; female, 14 to 18™". Worm similar in appearance 
to Dochmius cernuus, but having its head bent into the form of a hook. Head ter- 
minal, very short, somewhat thicker than the neck, and separated from it by a con- 
striction. Papille six, of which two are dorsal, two ventral, and two lateral. The 
latter are more obtuse and are the openings of the lateral canals of the body. Mouth 
terminal, supplied with a chitinous armature, consisting of an annular ring, which 
supports two systems of twenty-four teeth each; the outer circles are very long and 
curved, so that near their base they form a truncated cone and at their free extremi- 
ties an inverted truncated cone. Within the outer is situated the inner and shorter 
row of bidentate teeth, so arranged that each tooth is opposite one in the outer row. 
Beneath the armature is the tri-radiate opening of the esophagus. Neck not inflated, 
but provided with a lapel or fold of skin on the ventral side just in front of the 
ventral cleft; the fold continues slightly on to the dorsal side. Two lateral, narrow, 
membranous wings begin at this neck fold and continue for one-fourth the length of 
the worm. The two lateral opposite papillw are in these wings, at the level of the 
first third of the esophagus. The pair of unicellular neck glands unite into a com- 
mon duct and empty at the ventral cleft, situated beneath the nuchal fold. Male 
about three-fourths the length of the female. Bursa saucer-shaped ; can be spread 
symmetrically without tearing. Coste or ribs symmetrical; the ventral slightly 
separated; the ventro-lateral forms with the lateral a group; the lateral also 
slightly separated ; the dorso-lateral forms with its fellow and the dorsal pair a 


168 


group; the dorsal rib is composed of two, which are widely separated only towards 
their free ends. Spicula two; awl-shaped, bordered by a very narrow membrane; 
the chitinous cylinder is apparently fenestrated. At either side of ihe genital erifice 
are two knobbed papille. Female relatively stouter; vulva just in front of anus, 
which is midway between it and the acutely pointed tail, usually covered by a hard 
brown patch; reproductive organs in two symmetrical sets anteriorly directed, ex- 
cept a small portion of one, which is at first posteriorly directed to form a loop in 
front of the anus. Uteri two, in the caudal end of the body. These may be traced 
up to the oviduct and ovaries, which continue to the cephalic end of abdomen, where 
they are reflected to form a loop and thence continue to the caudal end to form still 
another loop. The ovary of the caudal uterus forms still another loop nearly oppo- 
site the uteri. 

Eggs laid with gastrula inclosed; length, 0.09™™; width, 0.05™". Embryos from 
0.23™™" upwards. The largest found in tumors were 4™™ long; the smallest male 
found in intestine was 7™™ long. The smallest embryos were without digestive ap- 
paratus. The largest possessed an intestine, unicellular glands, and a well-formed 
chitinous spherical eup in the head; also six cephalic papilliw, and at the neck two 
papille and a well-defined fold. 

Occurrence.—The adults live in the large intestine of sheep below the 
cecum; the embryos live in the intestinal walls in tumors, which, 
though more abundant in the cecum, may be scattered trom the duode- 
num to the anus. The species is distributed in the United States east 
of the Mississippi River as far north as Maryland, perhaps farther north. 
On comparing the species with others of the genus it was found that it 
corresponded more nearly with Qsophagostoma venulosum, a parasite of 
goats, than any other described in modern works, and that it corre- 
sponded still more closely with O. acutum, Molin. (JU sottordine degli 
acrofalli. Memorie dell * * * Istituto Veneto, 1860, Vol. LX, p. 
449.) The latter is apparently a distinet species, although in quoting 
other authorities he has given an incorrect synonymy. 9. Columbia- 
num differs markedly from O. venulosum in not having an inflated neck, 
and from the Jatter and O. acutum by the possession of a lapel of skin 
upon the ventral side of the neck, just in front of the opening of the uni- 
cellular neck glands. Molin examined two males and three females of 
O. acutum from Antilope Rupicapra; one male from Capra Hircus, var. 
Mambricus, in association with forty-five Sclerostoma hypostomum ; and 
two males and one female from Capra Ammon. The finding of Scleros- 
toma hypostomum in association with the Gsophagostoma acutum is the 
fact which leads me to infer that the latter occurred in the large intes- 
tine of the above mammals and not in the stomach, as he cites in his 
synonymy of the species. 

Life history.— @sophagostoma Galinbiantan seems to have become a 
parasite of sheep since their introduction into this country. If present 
in the Old World at all it is sparingly so, and seems to have escaped 
detection. So little is known about its distribution, that it is impos- 
sible at present to accurately define its limits. From its great abun- 
dance in the Southeastern States one might infer that it had originated 
as a sheep parasite in that region, and probably from some animal of 
allied organization and habits. The writer is at preseut inclined to 


169 


believe that the deer may have been its host at the time European 
sheep were first introduced. There are few facts to sustain this hypoth- 
esis. Though it may yet be too early to form a positive conclusion, 
further investigation may determine the section of the world to which 
this parasite originally belonged and then the former host may be in- 
dicated with tolerable accuracy. 

The life history of this parasite seems to be completely known to us 
during its development from the immature form found in the intestinal 
tumors to the adult stage; but there is a period from the moment 
when the eggs escape from the intestine with the excrement to the 
time when it is found again in the intestinal tumors that must remain 
in obscurity. After the embryo has returned into the alimentary canal 
it makes its way through the mucous coat of the intestine and becomes 
encysted there. The writer has been unable to learn how it passes 
through the mucous coat, as even on the youngest specimens no sign 
of armature is found. The very young forms found in the cysts show 
little differentiation beyond what they could bave attained in the egg- 
shell. They are soor. surrounded by a cyst which seems to belong to 
them and to have been created by them; but whether this cyst is the 
remains of a molt or not can not be asserted. Later in their history 
they become surrounded by the products of the inflammation they ex- 
cite in the surrounding tissues, and eventually break from the cyst and 
live in the cheesy mass of the tumor. In this stage of their growth the 
worms exhibit the intestine and oral cup and indistinct unicellular 
glands. They then molt, and show all these features in more distinct 
outline. Having attained a length of from 3 to 4™, or less than one- 
sixth of an inch, they break from the tumors to begin their life in the 
intestine. In the latter they continue their growth and becoming sex- 
ually perfect and produce eggs which eventually go through the same 
cycle. 

In developing, this worm molts at least three times—once in passing 
out of the stage in which it has no mouth or intestines, once during 
the development of these parts as we find them in theembryo, and 
once while the worm changes from the embryonic form to the adult form. 

Disease.-—The harm that these parasites do the sheep is directly 
dependent on their numbers and life history. Yearlings may show 
considerable infection, but it is usually in older sheep that the most 
abundant infection occurs. The disease is a seasonal one, in that it can 
be found in best development in the winter. The lambs begin to be in- 
fected in the summer and fall, and from that time the tumors formed 
increase in size until early in the spring of the next year, when they 
gradually grow smaller but probably do not entirely disappear. 

Pathology.—A study of the fresh tumors by compressing the smaller 
ones between two glasses and by dissecting larger specimens gives the 
following results: The small tumors, which are scarcely the size of a 
pinhead, are foundin the sulinneous tissue. They appear like asac filled 


170 


with fluid and having a little globe floating within. By using a higher 
magnifying power the little globe is seen to be a eyst with a worm 
inclosed (see Plate X XV, Fig. 6). By careful dissection the cyst may be 
separated (Fig. 5), and finally the worm itself may be separated (Fig. 3). 
At this stage the worm shows little differentiation of parts. In exam- 
ining another and oider cyst (Plate X XV, Fig. 7) the same appearance 
may be observed. There is also a little greenish cheesy substance 
present. <A third stage (Plate X XVI, Fig 3) shows the latter still fur- 
ther increased, and in the figure referred to the arrow shows that the 
encysted worm has been pressed out of this mass, leaving a cavity be- 
hind. 

When the little tumors become larger than a pinhead and entirely 
filled with the cheesy matter their structure does not materially change, 
but is more difficult to make out. It is at this stage that the worm 
escapes from the eyst aud begins to wander within the capsule which 
its presence in the tissue has caused. On dissecting the large fresh 
tumors the worm is found in the mass of cheesy material, which is now 
quite abundant, filling the cavity and producing tumors as large as 
the end of one’s finger. This cheesy material is usually hard, dry, and 
brown at one end, and soft, yellowish-green at the other. It is in this 
end that the worm is to be found. If some of the harder tumors are 
examined, it may be found that there is no greenish material in them and 
no worms. ‘These hard tumors may be of all sizes and are found at all 
times. From these the worm has either escaped or in the case of the 
smaller tumors the worms have died. The form of these tumors is 
usually spherical, but the cheesy material may appear as a long mass, 
or it may apparently fill what seems to have been a worm track. The 
last appearance occurs most often in the small intestines. From the 
mucous side these tumors present little if any color. The older ones 
may present a greenish-yellow appearance, especially if the mucous 
membrane over them be thin. In well-advanced cases, when the tuinors 
are numerous and large, many are found in which the mucous membrane 
over them is ruptured and the cheesy mass protrudes into the intestinal 
cavity. In these no worms have been found, and hence the conclusion 
has been reached that the worms have escaped. 

In lambs the little dots indicating the presence of the young tumors 
are very scattering (see Plate XX VI, Fig. 1), but in older sheep they 
may be very numerous (see Plate XXVII, Fig. 1). Between the stage 
in which a few are scattered here and there over the cecum and that 
in which the cecum has become a stiff tube with walls from one-fourth 
to one-half inch in thickness (so thick and close have the tumors be- 
come) there are all varieties. The tumors may extend from the execum 
to the anus. They may also be abundant along the small intestine. 
The cheesy material which the worms produce has been found in the 
lymphaties, on the omentum, and in the liver, but in these places it 
never seems to be sufficiently abundant to show that the parasite lived 
long. 


11 


Microscopie serial sections made from alcoholic specimens show best 
the changes which have taken place in the surrounding tissue. On 
Plate XXVI, Fig. 2, there is figured an enlarged view of one of the 
worms still eneysted and surrounded by the tumor of inflammation. 
From this section it is seen that the irritation setup in the adjoining con- 
nective tissue causes the cells to proliferate and crowd closer and closer 
together. It is also seen that there is a special cyst for the worm and 
a thickened adjoining portion of the tumor which is like a surround- 
ing membrane. As these two membranes, the so-called cyst and the 
outer one, stain so nearly alike, it has occurred to me that they represent 
successive efforts of the adjoining tissue to protect itself against the 
parasite; but in view of the fact that the inner one is so easily enucle- 
ated, it is for the present considered as belonging tothe worm. At the 
foot of Plate XXV, Fig. 8, there is given an illustration of a smail 
tumor in which the worm has escaped from the eyst and in which the 
surrounding matter has become cheesy, some of it even hard. Around 
the entire mass the tissue is slightly thickened and forms a capsule. 

From these two microscopic sections we can learn how these tumors 
grow. The worm penetrates to the submucous tissue and irritates it. 
The adjoining cells rapidly increase in number and crowd upon each 
other. So closely do they crowd and so numerous do they become, that 
the outer layers cut off the circulation from the inner cells and they 
die. Their degeneration gives rise to the cheesy mass. Now, if the 
worm remained in the center of the mass the new growth would event: 
ually cease, but the worm makes its way to the outside and at that 
point keeps up this irritation and new growth. This is shown by and 
accounts for the dried older parts of the larger tumors and the fresh 
yellowish-green adjoining parts. As soon as the worm escapes the irri- 
tation ceases, the tumor shrinks, and absorption of the mass begins. The 
irritation produced by the worm provides it with food and favorable 
surroundings for development. Often the worm dies from weakness or 
other cause, and leaves behind those little hard incompletely-grown 
tumors which have been mentioned. 

Since writing the above life history two post-mortem examinations 
have been performed, which lead me to modify my views regarding the 
life history of certain other tumor-making parasites. On August 10, 
1889, two lambs, one five months old, the other eleven weeks old, died. 
The older lamb was bred at the experimental farm; the younger was 
bought with its dam when but a day or two old. These lambs had no 
water save what was pumped from a well. Among other parasites, 
each species being found in its proper portion of the intestine, there 
were numbers of individuals of Gsophagostoma scattered through the 
length of the large intestine. These individuals were of all sizes, from 
the smallest stage (7™™ long) to those nearly adult. In the younger 
lamb there were but few very minute tumors in the coats of the large 
intestine. In the older the tumors were somewhat larger, but none were 


172 


much larger than a millet seed. The abundance and size of the free 
parasites indicated that most if not all of them had developed in the 
interior of the tube. The intestinal tumors indicated that there were 
others developing in them. 

From the above it seems probable that this species develops nor- 
mally in the intestine, that some of the young embryos penetrate into 
the walls of the intestines, and at times even to the mesenteric lym- 
phatie glands and elsewhere; that those which penetrate into the intes- 
tinal wall either develop very slowly or eventually die, depending on 
the tissue penetrated and the favorable conditions the latter offer for 
the nourishment of the parasite; that those which develop slowly may 
in time escape from the tumors and complete their development in the 
intestinal canal; that this phase of its life history may be one that is 
favorable for the preservation of the species by preserving a few indi- 
viduals in tumors throughout the winter which escape in early spring, 
become adult, and lay their eggs, which are scattered on pastures favor- 
able tothe preservation of the embryos; that the majority of these 
embryos, penetrating the intestinal walls, wander into such environ- 
ments that they are eventually destroyed; that this act of migration is 
voluntary and only of benefit to the parasite when the latter becomes 
lodged in the proper place, and that the same power which enables it 
to arrive at these places also enables it to penetrate farther than is of 
use to it; that the slow development of the worm in the tumors as 
compared with the development in the intestine shows it to be a re- 
tarded development, which may be hastened as soon as the parasite 
again reaches the proper surroundings. 

In short, the fact of the intestinal life of these parasites is demon- 
strated, as well as the fact that some may wander into the intestinal 
walls and undergo a retarded development before re-entering the in- 
testine. 

The diagnosis of this parasitic disease can only be made from a post- 
mortem examination. In the living sheep there may be signs of general 
debility—bloodless lips and eyes, thin sides and flanks, dry wool, ete. 
It may be that nothing else will be noticed, but that the flock is not in 
quite good condition ; or in severe cases the diarrhea and emaciation 
may be excessive. Dr. Salmon believes the disease may bring death to 
its victims in the severest cases. My own observations have been con- 
fined to the abattoirs, where salable animals only are brought. As the 
adult worms are comparatively few as compared with the tumors, it is 
probable that the adults of this species cause but little trouble; but the 
embryos, on the contrary, cause a great deal. The disease is an insidi- 
ous one, for not only is the rate of infection gradual, increasing slowly 
in amount from week to week, but the rate of development of the 
tumors is very slow, apparently requiring months. It is only when the 
disease is well advanced that its cumulative effects can be noticed. 

The disturbance of digestion caused by this parasite is mainly due to 


Ty 


Oo 


the derangements of the functions of the cecum. This derangement is 
not serious until the resulting tumors become exceedingly numerous, 
well advanced in growth, and press upon the more essential mucous 
membrane, disturbing its functions. 

The most seriously affected sheep found in the abattoirs are notice- 
ably poorer, and one would be tempted to believe, were he to judge from 
the “ knotty” viscera, as the butchers call them, that such animals 
should have died from the disease long before. These sheep usually 
have diarrhea, a disease which weakens the affected animals. Flock- 
masters who mistrust that their sheep are not doing well, and who 
know of no cause for it, should sacrifice one or two of the poorest to 
make a diagnosis. The meat of such sheep, though not quite as fat as 
other mutton, is suitable for food, and could not be distinguished in the 
market from other mutton. 

Prevention.—For the tumors caused by Gsophagostoma Columbianum 
there is no remedy except the removal and extermination of the adult 
worms. These adults are usually buried deeply in the mucous secre- 
tions and attached to the membrane of the large intestine. They may 
be found in considerable numbers in older sheep. The medicinal rem- 
edy must therefore be one which will remove them from these places. 
It is probable that such a one can eventually be found, but at present 
none can be recommended. It is probable that some one of the surer 
remedies advised for other intestinal parasites will do for these. In 
case medicinal remedies are tried each animal must be dosed. The 
killing of the adults wiil of course lessen the number of eggs with which 
the sheep become infested. As the eggs of this parasite pass to the 
ground the sheep may get them either while pasturing or drinking. 
The same care in changing pastures, in providing good drinking water 
and a plentiful supply of salt, should be observed as for other parasites. 
Judicious fall and winter marketing of infected sheep will also tend to 
lessen the chances of infection. If pastures are known to be perma- 
nently infected, then they should be turned over to other stock for a 
year or two before being again grazed on by sheep. When it is prac- 
tical on the smaller farms the sheep lots should be plowed and either 
planted or left fallow. The object of change of pasture and of plowing 
is nearly the same; in the one case, to wait until the parasites have 
died out; in the other, to bury them beneath several inches of soil, from 
which the sheep-owner may rest assured they will not emerge. 


Fig. 4. 
Fig. 5. 
Fig. 6. 


Fig. 6a. 
Fig. 60. 


Fig. 7. 


Fig. 8. 


Ss 


Fi 
Fi 
Fi 
Ki 


. 8a. 
9, 
10. 
Peis 


0¢ 0g 05 OF 


174 


MSOPHAGOSTOMA COLUMBIANUM, Curtice. 
PLATE XXIV. 


Adult male, x9, Fig. la, natural size. 

Adult female, x9, Fig. 2a, natural size. 

Cephalic end of adult, ventral view: a, head; b, cesophagus; c, lateral 
canals opening on head; d, unicellular glands and ducts uniting and 
emptying at e, the ventral orifice; f, a fold of the skin which forms a half 
ring on the ventral side of the neck; the orifice e opens uncer it; g,g, two 
pointed neck papillie; hk, h, narrow membranous wings; ¢, intestine. 

Caudal end of adult female lateral view, X45 (about): a, anus; b, vulva; ec, 
vagina; d, d, uteri; e, e, oviducts; f, f, f, loops of the ovaries; i, intestine. 

Head: a, mouth; bd, b, papille of the two lateral ducts; ¢, c, two of the four 
acute, pointed papillz opening on the head ; d, d, cross-section of cavity ot 
the head ; e, e, cross-section of a circular canal, which runs around the base 
of the head; f, chitinous armature of the head ; g, @sophagus; k, its three 
chitinous supports. 

Chitinous armature, top view: a, chitinous ring; b, outer teeth; c, inner 
teeth; d, triradiate pharyngeal orifice; e, e, e, the ends of the @sophageal 
rods. Four of the outer teeth have been removed to better show the inner 
row. A side view of this apparatus is presented in Fig. 5. 

Top view of teeth. 

Side view of teeth and basal support. 

The bursa spread out: a, ventral rib; b, ventro lateral; c, lateral; d, dorso- 
lateral; e, dorsal; f, the cloacal orifice with two papille behind. 

Spicula of male, composed of a chitinous tube surrounded by a membrane 
with a narrow wing. 

Portion of spiculum. 

Eggs: a, a, as they appear when deposited; >, eggs in uterus. 

Bursa of male, side view: a, a, a, ribs; b, spicula; ¢, ec, anal papilla. 

Head, top view: a, mouth; b, b, lateral papille; ¢, one of the four acute 
papille, 


PLATE XXIV 


Bolnmere. 


A.Hoen & Co, Lith. 


GSOPHAGOSTOMA COLUMBIANUM 
(The Tumor-Making Round Worm of Sheep.) 


Leek ate 
a o> oer 


ri oes iJ 


Kr pPaeey ae Thy Bini oie Aire, Screen er? TT 
meal toe (per es aera rs te, eel ee, a t;) na ar, PohigediTss! 
Pea 0 Ae oniten nny ar eh LO ee Mle Hy ey he = et 
; 1, ee ke qibtet aed Pree AL co iseca. tee a 
ek tits eH pv that oe 4 OS ively’ Niet hia : a 
< aes 7 nar bce 
we Ea) eet aT + fess pi eeu) aust mena ay ek iG r | 
; APO uc ae Rer LL 


ro dr ae Vite 


OPS ye Te a Sere ese ie oe de 
Rissitt, Pat ote his ws BT WD LaPorte gD Se a | 
: . 


rie Le RGU M Br RoC os gra) Teo 
m= Sapo ctr uli pied of ati) ores s/f amt 
; nt POT eee i ® eee ie: aS da Sayyed Date. tod Hast fed alt 
lady Aeris, ya Meter ah A Tis ee Tet see ate 
& Jot nge® 4 Mu eihj Ty OW WEBB ees owas Ali A 
Ree hey a Mitel fh rage chi palsy Hone dis ee 
4 SIMO yr PUIG ie Ee cu gt 
on eA mit iyo Ul esie Us AER mans ; 


sae oe say nine 5. TRIP Pi, er Bohra y mi an WeaAhee et tat 
Hee Okay 1 “ae ae ae ats Date ey ey 4Biirrey 


Peased ale oiee With fasssl tania GOLA ag salud 
LT aces 0 Gs itt! tet, See te echey 


.' & 


F al 


Bek ae 


5 vee 
> 


ig 


176 


(ESOPHAGOSTOMA COLUMBIANUM, Curtice. 
PLATE XXV. 


Worm in third stage, X60: a, head, with chitinous armature; b, @sophigus ; 
c, intestine ; d, unicellular glands; e, anus; /, line denoting patural length. 
Cephalic end, lateral view, X150: a, chitinous enp; b, one of the six cephalic 
papille, (these are slightly distorted) ; c, side view of the neck-fold, under 
which the gland-ducts d, d, open on the ventral line; ¢, wsophagus; f, 

intestine. 

Worm in first stage when 0.23"™, long. No internal organs were seen in 
this specimen. 

Cephalic end, ventral view: a, head; 6, neck-fold, near, which are the neck 
papille g, 9; ¢, esophagus; d, d, unicellular glands, which open under the 
fold b; e, intestine; f, f, glands. 

Worm inclosed in its cyst. 

Tumor from which the cyst in Fig. 5 was taken: a, surrounding tissue dis- 
sected from cecum; J, fluid-filled space; c, capsule with inclosed worm. 

Older tumor. This differs from tumor of Fig. 6, in having a movable cheesy 
mass. These tumors are distorted by compression, which makes them too 
flat. Figs.6and7, and Fig. 3, Plate XX VI, present three stages in the dis- 
ease, as seen in fresh tissues under low magnifying powers. 

Section of an advanced tumor: a, mucous membrane; }, submucous; c¢, inner 
muscular layer; d, outer: e, serous membrane; f, the cheesy mass of the 
tumor in which is a small section of the worm. This presents a more ad- 
vanced stage of the disease than Fig. 2, Plate XXVI, 


PLATE XXV 


=~ 


etn aes 


A.Hoen & Co. Lith. Balthnore. 


@SOPHAGOSTOMA COLUMBIANUM 


(Young Stages.) 


Fie. 


Vig. 


Fig. 


178 


(ESOPHAGOSTOMA COLUMBIANUM, Curtice. 
PLATE XXVI. 


1. A piece of mucous membrane taken from the cecum, surface view, natural 
size. The patch of dots scattered uniformly over the surface represents 
intestinal glands; the irregularly scattered larger dots and elevations are 
the young worm tumors 10 their first stages. 

2. A section through a worm tumor in its younger stage: a, a, a4, mucous mem- 
brane; b, submucous connective tissue, in which are ¢ arteries and d veins ; 
e, the tumor, which is made of connective tissue cells and their nuclei, 
packed closely together; near its center is the worm cavity f, with a piece 
of the worm, which is surrounded by a section of a special capsule; out- 
side of this is a thick membrane, formed from the surrounding material. 

3. Small tumor dissected from the cecum: a, the outside capsule filled with 
fluid, in which is b, a hard, cheesy mass: e, the worm in its capsule, which 
has been pressed out of the cavity in the mass >. This presents a more 
advanced stage of the disease than fig. 7, Plate xxv. . 


, 3a. The ruptured capsule. 
. 3b. The worm near the end of its second stage about to moult, 


| 
‘ 
| ; 
a 
if 
i 
’ 
es Haines, del. Hoen & Co. Lithocaustic, Baltimore, 
rd CESOPHAGOSTOMA COLUMBIANUM, Oho sake ees 


(Small Tumors of Cecum.) 


180 


(ESOPHAGOSTOMA COLUMBIANUM, Curtice. 
PLATE XXVII. 


Fig. 1. Piece of cecum exhibiting tumors caused by the embryos of Gsophagosloma 
Columbianum, natural size. The various stages of growth are represented 
by the different sized tumois. The smallest are better shown in Plate 
DOQYAS Nas Ie 

Fig. 2. Cross-section of Fig. 1, at aa; b, mucous membrane; ¢, submucous; d, 
muscular and serous layers; e e e, section through the cheesy masses. 


E XXVII 


PLAT 


Ee = Oe ee 


/ 


we 
RS 


Baltimore. 


&Co. 


A Hoen 


~ 
Sw ’ : . 
‘i 
- as j ‘ 
- e a 
t ¥ 7 
. - ; i. Ti 
Av FE 
x i 
ve 
‘ a : . 
| ‘ k 
’ 7 
* - - 
‘ 
7 > 
. 
17 . - Li 
“ - = 
i ‘ ae 
= 
ey 4 
| 
t 
. . 
— _ . 
* 
- . ’ 
@ « 
‘ 
‘ 
: 7 a ; . : = 7 t 
7 j ! —e = a - 


THE CACUM WORM. 
TRICHOCEPHALUS AFFINIS, Rud. 
Plate XXVIII. 


Description.—Male and female about equal, 40 to70™™ long. Body whip-like, pos- 
sessing a short, stout caudal end, 12 to 18™™ long, and a very thin hair-like cephalic 
end of twice this length. The latter contains the esophagus and intestine; the 
former the reproductive organs and intestine. 

The head is very small and thin, without noticeable papille or chitinous armature. 
It is said to sometimes have two vesicular, transparent, wing-like inflations. Skin 
of the neck transversely striate, and when highly magnified shows a serration of the 
sides indicating cuticular layers which overlap each other like shingles on a roof. 
(Esophagus and cephalic portion of intestine very minute; its posterior end is large 
and dark, and empties at the caudal end of the body. On one side of the head there 
appears to be a canal filled with granules, 

The male is to be distinguished by its tightly-curled caudal end. The testicle, 
beginning near the candal end, continues anteriorly as a sinuous tube for about two- 
thirds the length of the thick portion of the worm; it then becomes plaited to the 
end of the thick part, where if turns and continues posteriorly as an enlarged seminal 
duct for about half the length of the thickened body, where it is constricted; the 
remainder continues to the cloaca as a slightly enlarged tube. The intromittent 
apparatus consists of two parts, an external membranous tube bristling with spines 
and an internal long, slim spiculum. It is always found exserted, and usually has 
one ceil in it. The tube shows at its end that the external covering continues 
around the end into the tube to form a lining membrane, which may be retracted or 
protruded. There is considerable space between these membranes at the tip, and it 
assumes various forms, varying between a large sphere, as shown in the figures, and 
an elongate cylindrical body. The chitinous spiculum is terminated by an acute 
point. It is from 5 to 6™™ long, with a width of 0.025™™, The tube is about three 
or four times as wide. The spiny points are turned away from the‘end. 

The female has a thick body, only slightly curved. Tail, obtuse; ovary begins at 
the caudal end, continues as a plaited canal to the cephalic end of the thick part of 
body, then contracting returns to the caudal end where it enlarges, forms a fold, and 
becomes the uterus, which empties through the sinuous vagina and the vulva at the 
cephalic end, where the body begins to enlarge. Evgs characterized by having re- 
frangent polar bodies at each end. They measure 0.077™™ in length, including these 
bodies, or 0.056™™ excluding them (Raillet). They are elliptical and dark brown. 


Occurrence.—This species is found in the cecum of sheep, goats, and 
cattle. When the fresh intestine is examined the worm may be found 
with its slim, hair-like head firmly sewed into the mucous membranes. 
The serrated structure of the skin not only facilitates the progress of the 
head through the mucosa, but prevents its being pulled backward. The 
thick large end, which is what one really sees at first, appears to float 
free in the intestinal contents. 

181 


182 


The life history of this species has been determined by Leuckart, the 
distinguished helminthologist, who has added so much to this branch of 
biology. He succeeded in raising young embryos from the eggs to such 
astage that there was no reasonable doubt that the next stage was passed 
in sheep. These he fed to a lamb, which he killed after sixteen days. 
In these he found numerous immature trichocephali about 1”™ in length. 
He later verified this experiment by another, with like results. (Die 
menschlichen Parasiten, Band II, 494-499.) 

These experiments show that the eggs of Trichocephalus affinis, which 
pass from sheep to the ground, may develop there to some degree, and 
then, after being consumed with food or drink by a second sheep, con- 
tinue their development to their adult stages. 

Disease and treatment.—Unless the parasite should be present in great 
abundance the species does not seem to be especially harmful. A few 
may be found in nearly all lambs and young sheep, especially in the 
all. The means of prevention is just the same as for other round 
worms. As they are attached so stoutly to the mucous membrane it is 
doubtful whether medicinal remedies would have the influence on them 
that they have on those worms situated in the small intestine. 


TRICHOCEPHALUS AFFINIS, Rudolphi. 
IAEA) SOQ NOE 


Piece of cxcum with trichocephali attached, natural size: a,a, females; b, b, 
males. 


. Male, X7: a, capillary cephalicend; b, coiled caudal end ; ¢, protruded intro- 


mittent drgan; d, the convoluted, and e, the straight portion of the seminal 
apparatus; f, seminal reservoir; g, intestine. 

Female, X7: a, capillary cephalic end; b, vulva; ec, vagina; d, uterus; e¢, 
oviduct; f, convoluted ovary; g, intestine. 


. Caudal end of male enlarged: a, end of the body; b, spine-covered tube of 


intromittent organ; c, its inflated end; d, spiculum. 

Cross-section of end showing how the outside sheath becomes converted into 
the inside sheath of the tube: a,a, thesheath; b, the sac formed; ¢, the 
hollow spiculum. 

End of sheath, much enlarged, to show the relation between sheath and 
spiculum. 

The head. 

The vulva and vagina, with an egg in the passage. 

Eggs: a, eggs without shells; 4, egg with shell and its characteristic polar 
bodies; ¢, intermediate between a@and b. 


‘ig. 10, Enlarged portion of worm from near the head. 


PLATE XXVIII 


A.Hoen & Co. ith. Baltimore. 


m.) 


TRICHOCEPHALUS AFFINIS, 
(The Hair-headed Round Wor 


LUNG- WORM DISEASES.—PAPER SKIN, HOOSE, HUSK. 
VERMINOUS PNEUMONIA—VERMINOUS BRONCHITIS. 
Plates XXIX to XXXVI. 


The lung worms which cause disease in sheep in the United States be- 
long to two, perhaps three, different species. They are Strongylusovis- 
pulmonalis, Diesing, the hair lung worm; and Strongylus filaria, Rud., 
the thread lung worm. The third species, which has been reported as 
infesting sheep in Europe, is the hog lung worm, Strongylus paradoxus, 
an abundant species occurring ia the Jungs of swine in this country, 
and while ithas never been credited as having been found in our sheep 
it is to be looked for. As its size and the disease it causes is similar to 
that of Strongylus jilaria, it will not be treated separately. 

The diseases produced by these species of worms are caused by the 
mechanical injuries the worms inflict on the delicate membranes of the 
lungs and the clogging up of the air passages by them and the débris 
which they produce. The two forms of disease produced depends on the 
different size and habits of the two species. Strongylus ovis-pulmonalis, 
being very small, penetrates the air passages to their endings in the 
bronchioles and infundibuli, and causes disease in them primarily, 
while Strongylus filaria, which penetrates only into the bronchi, creates 
a disturbance there which produces a solidification of the lung second- 
arily. The general diagnosis of each disease is no easy matter. The 
disease produced by Strongylus ovis-pulmonalis is characterized by the 
spongy feeling of the lung and the presence of nodules from the size of 
a mustard seed to that of a pea scattered under the surface of the dor- 
sum of thelung and at its posterior free edge. These may be connected 
by agrayish, fleshy, intermediate portion of the lung into patches of con- 
siderable size. The parasites can scarcely be seen by the unaided eye; 
but if small pieces of the affected lung or a tubercle be placed in a shal- 
low dish of water and teased out with needles under a tripod lens, they 
can be readily seen. 

The disease produced by Stronglyus filaria and S. paradoxus is char- 
acterized by the posterior portion usually, or some entire section of the 
affected lung appearing as a solid, usually red, mass which has lost all 
of its contained air and is in a state of hepatization. A piece cut out 
generally sinks in water, while pieces from the former disease float. If 
in the latter disease the trachea is carefully slit open and the branches 

185 


186 


traced down to the affected part the parasites will be found in thread- 
like bunches, completely filling the tubes. 

The symptoms of lung-worm disease in sheep can not well be diag- 
nosed in living animals unless the disease is far advanced, and then 
only in the severer cases. Sheep affected with either disease generally 
have pale, bloodless mucous membranes, harsh, dry hair, a dejected 
look, more or less difficulty in breathing, and often a deep cough. The 
bloodless condition of the sheep could arise from other parasitic 
troubles, but the disturbance of respiration should lead one to suspect 
lung parasites. 

Consumption or tuberculosis is apparently a rare disease in sheep, 
and is not liable to be confused with this disease, which can always be 
diagnosed by finding the parasite. Lung-worm disease differs from 
acute bronchitis or pneumonia in being of slow development, and is less 
severe in its symptoms. Worm diseases consume weeks in develop- 
ment, while acute diseases are begun and finished in a few days. 


THE HAIR LUNG WORM—VERMINOUS PNEUMONIA. 
STRONGYLUS OVIS-PULMONALIS, Diesing. 
Plates XXIX, XXX, XXXI, XXXII, XXXIII. 


Description.—Male, 16™™; female, 25"; width, male, 0.6™™; female, 0.17™™. Cap- 
illary integument of worm very transparent, the cavity of the body appearing as a 
dark line. Head not winged; four papillze ; mouth naked. Male, bursa pointed, 
compressed, terminal; costie (apparently) seven; one posterior ; twice-notched ; two 
pair lateral, one pair anterior; spicula symmetrical, spatulate, eurved; 0.15™™ long, 
divided into two nearly equal parts; the anterior consisting of a cylindrical chitinous 
skeleton with a membraneous expansion, the posterior of a transversely ribbed skele- 
ton, margined by a thin broad curved membrane, the two spicula forming a partially 
closed tube. Female oviparous, with two uteri and ovaries. The formerempty into — 
a vagina at 0.8" from vulva. Vulva 0.1™™ from anus. Anus 0,08" from tip of 
tail. Tail ends ina blunt point. Eggs in uteri 0.1™™ long, 0.04™™ wide. The eggs 
segment after being laid. Embryo provided with a very sharp-pointed tail. 

Life history.—The young of the hair-lung worms escape from the lungs 
of infected sheep and become scattered over the pastures, yards, and 
other places frequented by these animals. They are then taken with 
the food or drink and in some way arrive in the lungs of the sheep. 
Arriving at the extreme ends of the bronchial tubes, they break down 
some of the tissues and become encysted. In the cyst they grow to 
adult size and take on sexual characteristics. Escaping from the eysts 
they make their way into the small air-tubes (bronchioles and bronchi), 
where the sexes mate and reprodace. The eggs are then laid in sur- 
rounding cavities and hatched into young worms, which make their way 
into the neighboring air-chambers (infundibula). Afterwards some of 
these worms may be coughed out of the lungs onto the pastures and in- 
fect other sheep. 

In their life history there are but one or two points about which there 
can be any question. Many learned belminthologists believe that the 


187 


young worm must escape from the sheep in order to spend a portion of 
its life on the ground or in some of the minute forms of animals before 
they are capable of further development in the sheep. Most authors 
are agreed that the worm passes into the lungs by the trachea either 
during feeding or rumination. The length of time which it takes the 
worm to complete its cycle of life is yet unknown. As the most pro- 
nounced cases among slaughtered animals are in the older sheep, it would 
seem as though this parasite was of very slow growth, requiring years 
instead of months for successive generations to produce a disease fatal 
to the infested sheep. It may be, however, that many lambs and 
young sheep are so seriously affected with the parasite that they either 
die or become so inferior in quality that they are never taken to the 
abattoir. In this case the cycle of life would prove to be rapid. 

Disease.—The diagnosis of verminous pneumonia in living animals 
is a difficult matter. Not until the disease is so far advanced that its 
cure is hopeless are any well-pronounced symptoms developed. The 
worst affected sheep may have a deep cough, be out of condition, and 
be generally anzmic, as shown by the pallor of the visible mucous mem- 
brane and the dry, harsh coat. They are likely to lose flesh, but some, 
if not seriously affected, fatten tolerably well. 

The post mortem diagnosis is as certain and definite as the diagnosis 
in life is unsatisfactory. So pronounced are the lesious caused by the 
worms inthe lung tissue that any one having once seen a diseased 
lung would easily recognize it again. The little tubercles, filled with 
greenish material and surrounded by more or less of the thickened 
lung tissue which when cut exudes a frothy liquid, are diagnostic. 
The presence of the worm in these tubercles is decisive. 

The prognosis of this disease can not be definitely given. From many 
examinations of affected lungs it seems to me that the disease is a pro-— 
gressive one, producing its worst effects as the sheep grow old. Where 
the sheep are marketed young the loss from this parasite is compara- 
tively small; but where the disease is wide-spread and affects whole 
flocks, though but a few cents may be lost per head, the aggregate loss 
to the sheep industry must be considerable. To this must be added the 
loss from the disease in its more severe stages. When the disease is 
once in a flock and the farm or range is infected with it there will bea 
steady loss resulting until the disease is in some way exterminated. 

Pathology.—The disease created is dependent upon the life history of 
the parasite as to character and upon the numbers of the invading hosts 
for its intensity. The changes produced in the lungs are but the agere- 
gate of all the changes which result from the different invading individ- 
uals, and the history of the changes wrought by a single parasite illus- 
trates the changes produced by all. The minute worm, when entering, 
penetrates the air passages to their extremities. In the ultimate alveoli 
it breaks down some portion of the membranous partition and becomes 
surrounded by the products of the inflammation which it excites and 


188 


formsavery minute tubercle. When this tuberele has reached from one to 
two and one-half millimeters (one twenty-fifth to one-tenth of an ineh) in 
size, it is composed of a distinct central part, filled with a soft, greenish, 
central portion, which is surrounded by a thicker nembranous capsular 
portion, composed of cells of new growth, the inner part of which degen- 
erates later and enters into the formation of the cheesy central mass. 
Within this tubercle is the young parasite. Inlater stages this tuberele 
enlarges untilit becomes 3™™ in diameter, In this stage the soft interior 
mass will be firmer. The parasite is always found between the interior 
mass and the capsule, and is surrounded bythe soft, freshly-formed 
greenish material, which it seems to produce by the irritation of the 
adjacent capsule. When the parasite attains its adult size it evidently 
breaks from the tubercle and thereafter lives in the adjacent bronchioles. 
There is quite a difference in the external appearance of the little tuber- 
cles during the different stages of growth. In the earlier stages they 
appear as little blood-red spots just beneath the pleural coat of the 
lung; later they look like little brownish fluid-filled tumors, surrounded 
by a red zone; still later a yellowish, green, cheesy material appears in 
their center, and the tumors present a greenish-gray appearance. The 
eray is due to the thickened capsule and a thickening of the pleural 
coat of the lung over the little tubercle. There is usually a slight ele- 
vation of the surface of the lung over these nodules, but this feature is 
dependent on the depth at which the nodule is situated. They may 
oceur at any depth in the lung substance, but are usually near the sur- 
face. When the parasite escapes from the nodule a new phase of the 
disease begins. It wanders through the bronchi until it meets one of 
the opposite sex, when they mate. Soon after the female begins to lay 
éges in the bronchioles and alveoli, which she infests, and these eggs 
in turn hatch into young worms. These young worms are very lively, 
and help to increase the disturbance of vital functions of the lung sur- 
rounding them. That part of the lung then becomes as if sodden, the 
air tubes fill with eggs, worms, cast-off epithelial cells, mucus, wan- 
dering cells, and air globules; the tissues of the walls of the alveoli 
become thickened and encroach upon the contents, and the function of 
the part is entirely suspended. The effect of the worm and its brood 
at this stage is to produce a pneumonia, hence the disease has been 
termed verminous pneumonia. This pneumonia is limited to the neigh- 
borhood of the parasite and does not extend beyond, The patches are 
from 1 to 2.5°™ in width, but in those recently formed they rarely ex- 
tend more than 2 or 3™™ deep. The injury seems to be mainly a me- 
chanical effect, due to the irritation set up by the parasites. When 
one of these patches is cut into a frothy liquid exudes, bearing quanti- 
ties of eggs and embryos in all stages of development. They may be 
seen with a glass magnifying six diameters. 

In later stages of the disease the tubereles become little hard masses. 
These have been said to be caleareous, but they are not soluble in acid, 


189 


and seem rather to be the contracted, hardened remaius of the cheesy 
mass. There are sometimes found in certain lungs raised patches of a 
rather dry, emphysematous tissue, which seems to be due to the deeper 
lying parasites. in other lungs the patches which once showed the 
pneumonia have becomed thickened, firmer, denser, and a cut across 
them shows the thickening to extend to a considerable depth. 

The abundance of the nodules and patches of pneumonia is very vari- 
able. There may be a dozen nodules of different sizes and twoor three 
patches, or the nodules may be diffusely scattered over the whole pos- 
terior surfaces of the lung, or there may be associated with them numbers 
of patches due in part to the close proximity of the nodules and in part 
to the extension of the disease. In other cases there may be a few of 
the nodules with a series of patches ranged along the dorsum of the 
lung. Hach lung seems to present a slightly different phase, dependent 
on the degree and the time of infection and possible reinfection. 

Source of infection.—That verminous pneumonia is caused by a worm 
(Strongylus ovis-pulmonalis) and that sheep become infested while feed- 
ing or drinking has @&lready been enlarged upon. It is obvious, there- 
fore, that the best way to keep the sheep well is in some way to pre- 
vent them from becoming infected with the parasite while feeding. 

Preventive treatment.—In giving rules for prevention the value of 
knowing the complete life history is fully illustrated. The unexplained 
gaps in this history are two, viz: there has been no complete demonstra- 
tion of the manner and place in which the parasite spends its life be- 
tween the time of its escape from the lung of one animal and its recep. 
tion into that of another, nor has it been demonstrated that the worm 
must escape from the luug before it may complete its development. 
This latter item is an important one, for if the worms can continue 
multiplying indefinitely in the lung then there is little hope of freeing 
a sheep after it is once infected. On the other hand, if an infected 
sheep is to be regarded as incapable of continuing the infection within 
itself then the case is more hopeful. If the parasite must become para- 
Sitic on a second host while external to the sheep, as some claim, this 
isan important factor in its life history, for its continuance then depends 
on the presence, abundance, and seasonal appearance of this second 
host, and influences adverse to the life of the second host would be un- 
favorable to the parasite. 

As the parasites are present in the lungs of sheep throughout the 
year in all stages, this theory does not seem to hold good. The infee- 
tion of lambs is proof enough that the parasites are continually passing 
from one sheep to another, and whatever be the mode of living there 
are certain precautions which may be taken to keep the sheep less in- 
fected if not to entirely exclude the worms. The older sheep, which 
seem to be more infected and which are the source of infection for young 
ones, Should be marketed. Lambs should be weaned as early as they 
safely cau be, separated from the older sheep, pastured in fields where 


190 


there have been no sheep since the previous winter at least, and never 
allowed to pasture, water, or yard after infected animals. 

Sheep should be supplied with water from running streams or troughs, 
and should not be allowed to contaminate the waterin any way. Filthy 
drinking water is one of the most prolific sources of the parasite. 

There are two kinds of seasons which especially favor the production 
of parasitic diseases. The one is avery wet, warm season, during which 
the parasites seem to be able to live on the damp ground. The other 
is a very dry season, when the pools of water become diminished and 
stagnant, and whatever parasitic eggs or embryos there are in them are 
gathered into so small a volume of liquid that sheep drinking of the 
water become more readily infected. Wet, damp pastures, and pastures 
with puddles in them are alike favorable to the worm diseases. Sheep 
should be excluded from such places as much as possible. 

A constant watch of the condition of the lungs in dead and slaugh- 
tered sheep will enable the flockmaster to judge of the progress that 
his care in preventing the disease has made. 

Medicinal treatment.—There is no medicinal treatment that can be 
profitably followed. Salting, grain-feeding, and healthful surroundings 
are required not only to keep up the health of the animal for the pro- 
duction of wool but to fit it for the market, which is the best place for 
seriously affected sheep. 


192 


STRONGYLUS OVIS-PULMONALIS, Diesing. 


PLATE XXIX. 


. Cephalic end: a, w@sophagus; b, intestine. 
. Head with papilli. 
. Caudal end of female: a, anus; b, vulva; c, vagina; d, d, uteri; e, e, ovi- 


ducts; /, J, ova; g, g, intestine. 


. Middle of female with tail of male coiled around her. 
. Spicuium: a, cylindrical part of the skeleton; 6, spatulate ribbed part; c, 


wing of tube: d, membranous tip. 


. Spicula as they fit together. 

. Adult male and female, <6. 

. Caudal end of male: a, spicula. 

. Male bursa with appressed costie. 

. Male bursa with separated cost and spicula in situ, 
. Caudal end of female, lettered as in Fig. 3, 


PLATE XXIX 


A.Hoen & Co. Lith, Baltunore- 


STRONGYLUS OVIS-PULMONALIS 


‘The Hair Lung Worm.) 


A ¥ coe 


/ ew aeit ee Pre enn ast Ass riots 
y panes aA oyitn) = ai Cai add” meee Ts EE ror 
sheih ad 5s ifs Priseas adit Bunt. ape 2 BAe rit hae 


ated Janes 


194 


STRONGYLUS OVIS-PULMONALIS, Diesing. 
JNU) 2.OO.G 


Portion of left lung slightly affected by the strongyli. The purplish spots are those 
more recently invaded. ‘The small gray spots are older. The large gray spots are 
caused by the worms and their young, which have produced an appearance of local 
pneumonia. 


PLATE XXX 


Haines, del, Se A cl 


A Hoen & Co, Lithocaustic, Baltimore 


SURFACE OF LUNG RECENTLY INVADED BY STRONGYLUS OVIS-PULMONALIS. 


196 


STRONGYLUS OVIS-PULMONALIS, Diesing. 
PLATE Pees 


Left lung diseased by Strongylus ovis-pulmonalis, the hair lung-worm. Natural 
size. Each dot is caused by the irritation set up by a young worm, and its size cor- 
responds to the age of the worm. The larger patches consist at first of separate 
dots; as these enlarge they run together and finally become so fused that their 
identity is lost. The patches show the stage at which the worms become adult and 
produce their young, which wander into the adjacent air cavities. 


PLATE XXxXI 


SORE oe 


LUN 


ISEASED BY STRONGYLUS OVIS-PULMONALIS. 


GD 


¥ 


198 


STRONGYLUS OVIS-PULMONALIS, Diesing. 
PLATE XXXII. 


Portion of right lung, exhibiting an advanced stage of the hair lung-worm disease. 
The small dark spots show the youngest stages, the large patches show the disease 
well advanced, while the large light spots are the oldest. A section cut across one 
of these shows the depth at which the lung is affected. 


PLATE XXxII 


Haines, del. A Hoen & Co, Lithocaustic Baltimoce. 


SURFACE OF LUNG DISEASED BY STRONGYLUS OVIS-PULMONALIS, 


Fig. 


Fig. 


= 
Fig. 
Fig. § 


Fig. 


bo) an 


200 


STRONGYLUS OVIS-PULMONALIS, Diesing. 


EAT ONON LIT 


. Section of lung tissue through two small tumors caused by the worms X20: 


a, caseous degeneration of tissue in the center of the tumor; 6, the same 
in the pathway of the moving, growing worm; c, cut fragments of the worm 
(the pathway of the worm is interrupted between a and b, because the plane 
of the section did not include it); d, a bronchus into which the parasite has 
almost found its way; e, portion of a second tumor made by another worm; 
f, nearly normal tissue. 


. Section through an older tumor at the stage which has been likened to pneu- 


monia, X20: a, tumor with fragments of worms; }, fragments of an adult 
worm; ¢, eggs in segmentation stage ; d, embryos somewhat developed ; e, 
young embryos; f, bronchi; g, nearly normal tissue. 


. An enlargement of b, Fig. 2, showing fragments of adult worm in the bron- 


chi and alveole. 


. Anenlargement of e, Fig. 2, showing young worms in the alveolz. 
. An enlargement of c, showing segmenting eggs in alveoli. 
. An enlargement of d, showingd eveloping embryos in alveoli. In Figs. 5and 


6 the outlines of the egg-shells are not shown. Figs, 3-6, x90. 


(These illustrations were made from specimens selected from a number of serial 


sections which were stained with alum-carmine; the dots represent the 
nuclei of the cells. All sections show the great multiplication of cells 
about the points of irritation, whether excited by the adults or embryos.) 


Fig. 7. a, embryo of Strongylus filaria, and b embryo of S. ovis-pulmonalis, each equally 


enlarged to show comparative differences in size and outline. 


PLATE XXXII 


fo EET 
SY 
ee oa 3 a 


Haines, del. A Hoen & Co. Lith Baltimore 


SECTIONS OF LUNG DISEASED BY STRONGYLUS OVIS-PULMONALIS. 


THE THREAD LUNG-WORM—VERMINOUS BRONCHITIS— 
HUSK OR HOOSE—PAPER SKIN. 


STRONGYLUS FILARIA, Rud. 
Plates XXXIV, XXXV, XXXVI. 


The thread lung worm, or Strongylus filaria, is the best known of the 
sheep lung worms, for the reason that at times it causes extensive epi- 
zooties in the flocks, and that the worm is large enough to see when the 
bronchial tubes are slit and spread open. From personal observation 
it appears to be much rarer than Strongylus ovis-pulmonalis, and the 
disease it causes much less extensively distributed as to number of 
animals infected than that produced by the latter. In most of the 
American literature on this subject the disease caused by the hair lung- 
worm seems to be ascribed to the thread lung worm, and no mention is 
made of the former. 

Description.—Male, 33 to 54™™; female, 55 to 80™". Worm filiform, white, with 
a dark hair line showing throughout its length; head obtuse, withvut notice- 
able papille or wings; mouth circular, naked; unicellular neck glands quite large ; 
cuticle longitudinally striate. Male: Bursa shallow, campanulate, opening later- 
ally ; five sets of cost; the dorsal are trifid, the lateral bifid, and the ventral sepa- 
rated. Spicula arcuate cylindrical; 3.35™" long by 0.075™™ wide; short, very 
thick, dark brown; chitinous portion a curved fenestrated conical tube; fleshy por- 
tion amembrane, which formsa bulb-like expansion toward their free end. Female: 
Vulva three-sevenths of her length from the head; uteri symmetrically directed 
anteriorly and posteriorly ; posterior oviduct becoming continuous with the uterus 
near its flexure at the tail; ovo-viviparous; eggs ellipsoid, 0.075 to 0.120™™ long ; 
0.045 to 0.082™™ wide. Embryo 0.25 to 3™™. 

The life history of Strongylus filaria is in general that of other para- 
sites. In some way the young worms arrive in the bronchi, grow, de- 
velop, become adult, mate, and lay their eggs in the surrounding mucus. 
The eggs laid are not true eggs, for each egg-shell contains a young 
worm within, a feature which is described by calling the female ovo- 
viviparous. The inclosed young escape from the shell, and many of 
them are expelled from the lungs in the coughing fits along with other 
discharges. These young, which are scattered about watering-places, 
pastures, sheep-yards, or corrals serve as infecting and reinfecting ma- 
terial for a considerable length of time. Professor Leuckart (Hntwickel. 
ung ad. Nematoden, Arch. d. w. Heilkunde, 1865, p. 299), kept the young 
of this species alive for several weeks on damp earth, and observed them 
pass through a stage in which they molted or threw off their skins, 


201 


202 


after which many died. Baillet (Colin, G., Bull deV Acad. de Méd., t. 
XXXI, 1866, p. 874) preserved them alive in water for several months. 
Ercolani (Newmann, Traité des Maladies parasitaires, p. 515) is author- 
ity for the statement that they can be resuscitated after being dried a 
year by putting them in water. The writer has kept them in stagnant 
water for weeks. Ercolani’s statement is by far the most remarkable, 
and accounts for results obtained in an experiment in which the writer 
kept sheep for five months on a narrow dry pasture, supplying them 
with water from a pump only. When these sheep were examined they 
were found affected with Strongylus contortus, S. filicollis, S. ventricosus, 
Dochmius cernuus, and Tenia expansa in very young and old stages. The 
eggs of these were introduced on the pasture from two or three older 
sheep which were with the younger ones, or possibly by the young 
sheep themselves, some of which were between three and four months 
old at the time. Two of the lot were born and raised under experi- 
mental supervision, and these were also infected. Strongylus filaria 
was not present, but it was not discovered in any of the sheep from the 
same lot killed at the time of selection of the experimental animals, nor 
has any trace of this parasite been discovered in any of the older ones 
kept at the Experimental Station. 

Professor Raillet details experiments (Recueil de Méd. Vétérinaire An- 
nexe, 7 Serie, Tome VI, No. 8, April 30, 1889, p. 173) in which he dried 
embryos of Strongylus filaria under different conditions, and found, after 
a few failures, that some could be revivified as late as sixty-three hours 
afterward by placing them in water. His success depended on the 
condition of the embryo at the time of drying. 

It may be accepted, therefore, that the young parasite may retain vi- 
tality indefinitely, depending on telluric and atmospheric conditions. 
From Leuckart’s experiment it is to be inferred that though moist earth 
and damp places are favorable for the life of the young parasites, yet 
they are liable to molt and then may die from the loss of the olderand 
tougher external skin. From Ercolani’s and Raillet’s experiments we 
may infer that the drying of the young parasite suspends its functions, 
which revive again when the surroundings are suitable, and that the 
parasite is in this state the most dangerous to sheep. 

Preventive treatment.—The foregoing indicates that after a farm is 
once infected the prevention is not an easy matter, for dry embryos 
may be scattered everywhere. Although the parasite is more abundant 
at some seasons than at others, yet it may be found in limited numbers 
at all seasons, and animals affected will distribute the eggs throughout 
the year, thus increasing the difficulties of prevention. All animals 
which show the least appearance of being affected should be separated 
from the sound ones. The water supplied to the sheep should be pure, 
i.¢., either taken from wells or led into troughs from sources which can 
not be contaminated. If the sheep are allowed to drink from running 
water, then all of the brook should be fenced out except where the 


203 


sheep drink. Dry pastures without bog-holes or sloughs are best for 
the animals. As the germs live for some time ina dried condition the 
old pastures should not be used for young sheep at least, nor should 
the latter be allowed to graze after older sheep which have had the dis- 
ease during the previous year, nor should the pasture be overstocked 
so that the grass is eaten to its roots. 

Disease.—Verminous bronchitis attacks young animals, those under 
two years being the more susceptible. Animals poorly nourished and 
those already weak from other parasitic diseases are also more liable to 
become a prey to this worn. Damp, warm seasons are most favorable 
for the preservation of the parasite and the disease it produces. The 
disease is most prevalent in summer and autumn, becomes less in 
winter, and disappears in spring-time. 

The symptoms of this disease, as in verminous pneumonia, are im- 
perceptible in the first stages. It is probable that, beyond the slight 
but deep cough produced in some of the worst cases, but little else can 
be noticed. The sheep may have difficulty in breathing when driven 
or be short-winded. They may be anemic, as shown by the harsh, dry 
skin, dry wool, and pale mucous membranes. In later stages the 
symptoms will be aggravated; difficulty in breathing, coughing, and 
general debility, associated with an anemic condition, will be the most 
prominent symptoms. Occasionally shreddy masses will be coughed 
up, which, on close examination, will prove to be worms. This is a 
decisive test of the nature of the disease. 

The sheep has a fair appetite, but will gradually lose flesh. In the 
last stages the bronchial cartarrh is severe, the respiration very feeble 
and jerky, the cough deep, convulsive, and evidently painful, coming 
by fits and followed by suffocation, which leaves the patient still more 
exhausted. The nasal discharge becomes more copious, and contains 
quantities of embryo and worm fragments. Owing to the diminished 
respiration productive of anzemia, the skin becomes dry and harsh, and 
resembles parchment; hence the popular name “ paper-skin.” The wool 
is also affected and is easily pulled off, exposing the white, bloodless 
skin underneath. 

Duration.—Death occurs in three or four months either by exhaus- 
tion of vital forces or by suffocation. As the first stages pass unnoticed 
the total time from infection to death is probably nearer five or six 
months, The duration of the disease depends on the amount of infec- 
tion, the previous health of the patient, the care it receives, and its vi- 
tality. Where the symptoms are very decided the patients rarely sur- 
vive. The disease is most intense in autumn, and if the sheep do not 
die, it becomes less intense in winter to more or less completely disap- 
pear in spring. When the season has favored the development of the 
disease and the lambs show severe symptoms, the outlook for their re- 
covery is very unfavorable. A large percentage of those attacked die. 


204 


Others fall away in flesh to a serious extent and the growth of the fleece 
is retarded. 

Occurrence.—It is ausual thing to find lungs affected with Strongylus 
ovis-pulmonalis, and more rare to find them affected with S. jilaria. 
When the latter occurs it is ordinarily associated with the former, 
owing toits abundance, but it is easy to separate the two diseases. In 
the beginning of the S. filaria disease the very posterior tip of the lung 
is affected, turns dark red or grayish, and has a solid feeling and ap- 
pearance. From this the disease spreads anteriorly, lobe after lobe 
of the lung becoming involved as the bronchi choke up. These termi- 
nal patches are very sharply separated from the adjacent portion of the 
lung, which appears normal, except that it may be infected with S. ovis- 
pulmonalis, as indeed may be the part infected by S. filaria. The cause 
of this solidification or hepatization (so called because it becomes solid 
like liver) is the stoppage of the air tubes by the worms and the débris 
they produce. When they exclude the air from the part the air cells 
fill with débris and the part becomes solid. Portions of lobes elsewhere 
may become involved, but more rarely. The anterior lobes often ap- 
pear red and solid, but it will generally be noticed that in these the red 
part is thin and not as spongy and resistant as the lobes in the poste- 
rior end. This state is due to the air being driven out of the lobes and 
the walls coming together, producing a state of collapse (carnification 
or atelectasis). i 

The solid lung produced by S. jilariais often covered by a thickened 
whitish membrane, the inflamed serous membrane, which often grows 
fast to the chest or thoracic walls. After the worms disappear, either 
having been killed by remedies or from some unknown reason, the heal- 
ing process begins, and the lamb recovers if not too much weakened. 

Treatment of this disease is far more hopeful than that of the pneu- 
monia due to Strongylus ovis-pulmonalis. It may be dietetic, preventive, 
and medicinal. In an essay on this disease Mr. Stephen Powers (The 
American Merino, O. Judd Co., 1887, p. 283) says: 

To sustain the strength and vitality of a sheep already affected is exceedingly diffi- 
cult, because the appetite is feeble and capricious. The lamb can seldom be induced 
to eat enough even of the most nutritious food, to make any considerable impression 
on it in the way of betterment; and the danger in giving it by force stimulating 
gruels, etc., is that, owing to its bloodless condition, the process of digestion will be 
so illy performed that the food will do it more harm than good by causing scours. 
High feeding is of transcendent importance as a preventive measure; but when the 
lamb has reached such a pass that vermifuges have to be employed, it is necessary to 
proceed with great caution in giving rich food. 

These remarks commend themselves to all who have had experience 
with afflicted sheep. Keep the lambs up to the highest point of ex- 

sellence and health by feeding and they will the better withstand the 
ravages of the parasites. Corn and oats, bran, chops, and oil-cake are 
all good fatteners, and should be given in proper proportions. Salt 
should be placed where the sheep have free access, not only as a diet- 


: 205 


ary article, but for its medicinal influence. In addition they should 
have pure, fresh water once or twice a day. When the animals have 
become sick good diet should be supplied. As intimated by Mr. Powers, 
those animals which seem most in need of food take the least, and if 
they do eat it.may even be of harm to them. However desirable it may 
be to feed animals well as a hygienic measure, still no amount of feed- 
ing will keep them from being infected when a season favorable to 
the parasite appears. There must therefore be a continual diligence 
exercised in keeping the pastures in good condition and the young 
sheep especially from becoming infected. As the parasites seem to thrive 
best in water, it follows that dry pastures should be preferred. The 
danger of infection from pastures should be diminished by limiting the 
number of sheep, so that they will not have to eat the grass close to 
the roots, and by a judicious distribution of the young sheep on practi- 
cally virgin pastures. Should a pasture have become permanently in- 
fected from long use it should be plowed up and either cultivated a 
year or two or allowed to stand idle or surrendered to other stock. 
The effect of the cold upon the embryos of these parasites is not yet 
known, and it may be that the alternate freezing and thawing which 
they sustain is in the Northern States the cause of the destruction of 
large numbers of them. Leuckart’s experiment of keeping the worms 
in moist earth, during which time many molted and died, indicate 
that a pasture would be much safer when thoroughly dried after a pro- 
longed rain than before, and also that such a wet time would be more 
dangerous for the sheep. A judicious selection of pasturage through- 
out the year, together with a shifting of the sheep from pasture to past- 
ure as the season and ages of the sheep seem to require, is the best 
that can be counseled at present. 

Medicinal treatment may be productive of much good, but is usually 
resorted to so late that its best effects are lost. Medicines haye been 
administered with the food by drenching, by fumigations, and by 
tracheal injections. Salt and copperas in proportions of from 1 of cop- 
peras to 25 of salt, and of 1 of copperas to 4 of salt, the last mixture 
being given in wet weather, has been advised (The American Me- 
rino, by Powers, 1887, p. 285). The weaker mixtures may be kept con- 
Stantly before the lambs for eighteen months. The stronger should be 
alternated every two or three weeks with clear salt. Powers kept it 
constantly before the lambs until after the second summer. I would 
deprecate the use of copperas for any continued length of time, for it 
not only harms the teeth, but if persisted in loses its force as a tonic 
remedy. In administering dry medicines in food much of their force is 
lost, for they are very apt to accumulate in the paunch or first stomach. 
' Medicines given by drenching are more expensive in the dosing but 
more effective, for small quantities of fluids pass directly into the mani- 
folds or third stomach, and thence into the fourth stomach, especially 
if the sheep be thirsty. But few of the many remedies advised are in 


206 


the least effective except they be general tonics and stimulants. Many 
advise the use of anthelmintics, but these are of value only in driving 
off the intestinal parasites. Turpentine seems to be an exception to 
this rule, as some of it is eliminated by the lungs and so reaches the 
worms. Powers (op. cit., p. 283) advises turpentine and linseed oil mixed 
in equal parts, a tablespoonful at a dose. Mr. W. G. Berry saturates 
lumps of salt with turpentine, then crushes the salt, mixes with bran, 
and feeds as a preventive. 

Neumann (Maladies Parasitaires, p. 517) states that the following 
have been recommended: Picrate of potash, from 3 to 6 grains per dose, 
dissolved in oatmeal, water, or mucilage; a mixture of equal parts of 
turpentine and spirits of camphor, a teaspoonful daily in mucilaginous 
drink; a mixture of creosote 120 parts, alcohol 500 parts, water 700 
parts, dose a teaspoonful; creosote 60 parts, benzine 300 parts, water 
2,000 parts, dose a teaspoonful for each patient daily for eight days. 
Hall ( Veterinarian, 1868) says that he employed with success 10 drops 
prussie acid (to be diluted in water) for a dose morning and evening. 
Neumann adds, however, that experience shows there is little reliance 
on these methods of treatment, and the administration is, besides, more 
or less difficult. 

The same author states that success is less uncertain with fumiga- 
tions which penetrate directly to the worms, benumbs them, and pro- 
vokes a cough by which they are brought up and ejected. The sheep 
to be treated should be driven into as nearly an air-tightshed or stable 
as is practicable. Then rags, horns, feathers, hair, old leather, tar, 
asafetida, etc., should be placed on a red-hot shovel or in an iron pot 
filled with burning coals or in a tinner’s fire-pot. The intensity, dura- 
tion, and number of fumigations should be graduated according to the 
tolerance of the sheep. Either some person should subject themselves 
to the same fumigations, or a very close watch should be maintained in 

order to prevent the lambs suffocating. 

Tracheal injections —The method of treatment by tracheal injections 
promises much better results, but should only be practiced by a relia- 
ble veterinarian, who can oversee the results and take all necessary pre- 
cautions. The method has been detailed in the Second Annual Report 
of the Bureau of Animal Industry, 1885, page 284. It consists of intro- 
ducing remedies directly into the trachea by means of a hypodermic 
syringe which cause the death of the parasites. The medicines thus 
introduced have an opportunity of acting upon the parasites directly, 
before they are all absorbed by the mucous membrane of the air pas- 
sages. There is no reason to doubt that they may have even a second- 
ary effect after their absorption if they are naturally thrown off by the 
mucous membrane of the air-passages and the epithelium of the alveoli, 
which is the case with most volatile substances. 


The method of tracheal injections was first tried by Gohier in the early part of the 
present century, after learning experimentally that considerable quantities of liquid 
can be introduced into the trachea without producing suffocation. Delafond some 


« 


207 


years after conducted some experiments to determine the absorptive powerof the air 
passages. He found that mucilaginous decoctions and solutions of sugar or honey 
are speedily absorbed when injected into the trachea, inducing slight symptoms of 
suffocation for one or two hours. He also found that solutions of narcotic agents 
and stimulants manifest their physiological effects very soon after injection, and that 
oils and oily medicines produce a congestion of the lungs which is but slowly dis- 
sipated, and that even very dilute solutions of mineral and vegetable acids produce 
inflammation, with copious secretion of mucus, giving rise to symptoms of asphyxia 
and even leading to death. 

Dr. Levi, of the University of Pisa, has recently applied this method in the treat- 
ment of a number of diseases (Manuel pratique des injections trachéales dans le cheval, 
1883). His experiments also tended to show that the mucous membrane absorbs very 
rapidly, and is therefore less apt to suffer from the injection of irritating substances 
than if the absorption were less rapid. He also determined that the injection of small 
quantities of oily substances is not dangerous, the oil probably being emulsified and 
absorbed. Finally, there is always a slight reduction in the number of respirations, 
amounting to about three or four per minute, after the introduction of liquids, even 
when distilled water only is injected. 

Without entering into interesting questions concerning the administration of med_ 
icines in this manner in other diseases, which are discussed at length in the work 
mentioned, we find that the author has experimented on but one case of lung worms 
to test the efficacy of the method. Others, however, have reported cases in which 
their success justifies a detailed account of the method for future application. 

The instrument to be used is a simple hypodermic syringe holding from 1 to 2 fluid 
drams. The needle of the syringe must be provided with a removable solid rod or 
trocar, so as not to become plugged when it is pushed through the skin and walls of 
the trachea. As the needles are apt to break, a number of them should be kept on 
hand. After the operation the syringe should be carefully washed in pure water, the 
piston supplied with a drop of olive oil, and the trocar replaced in the needle. 

It is best to disinfect by filling the syringe and needle with a 5 per cent. solution 
of carbolic acid, or a 0.1 per cent. solution of mercuric chloride* before washing in 
pure water. The disinfection, however, is not absolutely necessary in this operation 
if the syringe and needle be kept thoroughly clean. 

To administer the medicine first fill the syringe and place at the side. Hold the 
sheep for drenching, and extend the head of the animal so as to fix and make promi- 
nent the trachea, which will be felt as a tense elastic tube along the middle line of 
the neck. The most convenient point for the introduction of the needle is at about 
the middle of the length of the neck. It must be remembered that some care is to be 
observed, as the trachea is near some important structures on either side—the jugular 
vein, the carotid artery, and the pneumogastric nerve. Having fixed the trachea 
with the left hand, the needle with the trocar is inserted beneath the skin, and then 
an interannular space is sought so as not to pierce a cartilaginous ring. Or the 
needle may be pushed directly into the trachea without necessarily avoiding a 
cartilaginous ring. The unimpeded movement of the free end of the needle as if 
in an empty space is asure sign that the needle is in its proper place. The trocar is now 
removed, the syringe screwed upon the needle, and the contents very slowly forced 
into the trachea. Before the needle is finally. withdrawn Dr. Levi thinks best to 
wash it out with some pure water so as to remove the injecting fluid. In withdraw- 
ing the needle this might accidentally be discharged in the wound made by the needle 
and set up inflammation if the substances introduced be irritating. How this wash- 
ing out is to be done he does not state. It seems that a small pipette or medicine- 


“The former is prepared by adding 5 parts by weight of pure carbolic acid to 100 
parts by weight of pure water previously heated ; the latter by adding 1 part of the 
corrosive sublimate (a violent poison) to 1,000 parts of water. 


208 


dropper filled with water and inserted into the end of the needle would suffice to wash 
it out, or drawing back the piston of the syringe would leave the needle compara- 
tively empty. ‘The needle might also be washed out by removing the syringe, wash- 
ing it out, filling with water, and forcing a few drops into the trachea through this 
needle. This, however, would cause unnecessary delay before the animal is released, 
and is therefore not to be recommended. The simplest method, then, to empty the 
needle would be to draw back the piston, for the discharge of anything but the purest 
water into the wound may produce more irritation than the medicinal substances 
themselves, The animal should be watched for some time, especially after the first 
operation, to observe how the injection has been borne, and whether any symptoms 
arise which indicate difficulty of breathing. 

If, as has been suggested, a slight incision be made in the skin before introducing 
the needle, and if a cartilaginous ring be avoided in piercing the trachea, the ordi- 
nary needle with beveled extremity will be sufficient, and the trocar may be dis- 
pensed with. When the needle has entered the trachea, a slight hissing noise, due to — 
the entrance and exit of air with each inspiration and expiration, indicates that the 
needle has reached its destination and is not plugged. 

The substances to be injected should have distinctly vermicide properties, with- 
out being at the same time too irritating or poisonous in their effects on the animal. 
Levi gives two formule which he used with success upon asheep. The worms were 
discharged in three days and the catarrh cured: lodine, 2 parts; iodide of potash, 10 
parts; distilled water, 100 parts, by weight. 

Begin with half a dram of this solution, add half a dram of water, and increase 
by half a dram of the above solution each day up to5drams. Anotherremedy is the 
following: Mix equal parts of turpentine and olive oil, and inject from 1 to 4 drams. 
In this case the writer probably intended to state that the dose should be increased 
from 1 to 4 drams on successive days. 

Eloire (Recueil de Med. Vet., 1883, p. 683) gives the following formula: Ordinary 
oil of poppy and oil of turpentine, each 100 parts; carbolic acid and purified oil of 
cade, each 2 parts. 

The oil of poppy, being a bland oil, does not possess any medicinal properties, and 
may be replaced by olive oil. Each sheep to receive about 2 dramsa day for three 
days. 

Six animals treated in this way showed immediate improvement and were finally 
cured. Penhale (Veterinarian, 18385, p.106) reports immediate relief and ultimate 
cure in two calves by injecting the following mixture: Oil of turpentine, 2 drams; 
carbolic acid, 20 drops; chloroform, 4 dram. 

One-half of this amount may be given to a sheep and the dose subsequently in 
creased if necessary. 

Hutton (loc. cit., p. 62) reports favorable results in six out of eight cases by inject- 
ing the above liquid, in which 1 dram of the tincture of opium was used in place of 
chloroform. 


This completes the list of remedies thus far suggested and tried. 
The favorable testimony, though not abundant, is very encouraging. 
There are many substances, no doubt, the-use of which might be more 
beneficial than those mentioned, but nothing can be said of them until 
they have been tested. . 

The dose for young sheep should be proportioned to the age and 
size of the animal. The preparations with turpentine seem to have 
given the best results. During treatment the patients should receive 
the best of care. 

The prevention of this disease is very desirable, though it may never 


209 


be completely attained. Ifa farm is completely free from it in the first 
place, then prevention simply lies in not allowing infected sheep to be 
brought on the premises. All purchases of sheep should be from flocks 
which have shown no signs of the disease in preceding years. Brooks 
which run from pasture to pasture offer a chance of infection where the 
neighbors’ flocks upstream are infected. Strange sheep should not be 
pastured unless they are known to be free from parasites. Feeding 
and care to keep up the general health are essential: Careful separa- 
tion of affected animals should be practiced, and the worst diseased 
ones may beslaughtered. Treatment should not be neglected. During 
treatment it is best to keep the sheep up, and after the course of treat- 
ment is concluded they should be turned into new pastures. 
230388 A P——14 


12 
0g 
— 


210 


STRONGYLUS FILARIA, Rud. 


PLATE XXXIV. 


. Adult female, x3: a, head; 6, vulva. 
. Adult male, x3: a, head; b, bursa and spicula. The dark line in Figs. 1 


and 2 is the intestine. 


. Cephalic end: a, mouth; b, wsophagus; c, intestine; d, unicellular glands, 
. Middle portion of female: a, vulva; b, vagina; ¢, c, uteri with developing 


eggs. 


. Piece of skin showing striz. 
. Spicula: a, the fenestrated chitinous cylinders; b, the bulb like enlargement 


of the surrounding membrane. 


. Caudal end of female: a, anus; J, b, intestine; c, loop of the caudal uterus , 


d, ovary. 


. Caudal end of male, ventral view: a, intestines; b, seminal reservoir; c, the 


torn edges of the spread bursa; d, ventral cost; e, ventro-lateral ; f, 
lateral; g, dorso-lateral ; h, dorsal; 7, spicula. 
. The same lateral view. 


. a, female, natural size; b, male, natural size. 


. Eggs showing various stages of development of embryo in the following 
order: a, b, c, d; e, embryo escaped from shell. 


V. 


FA : 
Py : 
> z 
> Z 
ca z 
a : 
& o 
cu é 
fu : 

¢ 


STRONGYLUS FILARIA, 
(The Thread Lung Worm.) 


{NTT re, 
jaasmDUh Taig ry 
Se a 


— 
te. . 
= Se. 


3 


212 


STRONGYLUS FILARIA, Rud. 
PLATE XXXV. 


Portion of right lung of lamb, dorsal view. The affected region is the dark col- 
ored posterior end. It is clearly marked off from the healthy portion. The dark red 
spot about the middle of the figure is also caused by the worms, but it is exceptional 
to find these lobes affected in early stages. 


, 


ea 


ees ws RE Ag 
' 


; “ b Yawn A Do. Ueiocemrt Bolten aey 


STRONGVIA® PHLARIA, 
_. |LAMB'S LUNG AFFECTED BY THREADWORMS, 


PLATE XXXV 


A.Hoen & Co. Lithocaustic, Baltimore. 


STRONGYLUS FILARIA, 


LAMB’S LUNG AFFECTED BY THREADWORMS, 


7s 7 
- up ; 
: : 
, 
P i 
F ; 
: : 
‘ 
el 
& 
a) r 
i 7 
& 
> * 
7) 
a 


= 
* 7 
2 
oh S 
' 
‘ ' 
: 
¥ => 
» « 
ith 
‘ 
} * 
. 
i : 


214 


STRONGYLUS FILARIA, Rud. 
PATH 2xcKeovil: 


Portion of right lung of lamb, ventral view. This is the same lung figured in 
Plate XXXV. The affected portion is in the posterior end. The lung tissue has 
been dissected to show the tracheal branches and the bronchi. The bronchi leading 
to the dark-colored affected region are filled with the life-sized figures of the Siron- 
gylus filaria, 


PLATE XXXVI 


A.Hoen & Co. Lithocaustic Baltimore 


Haines, del. 


LAMB’S LUNG INVADED BY STRONGYLUS FILARIA. 


mi 


a 


INDEX. 


Page. 
Abdomen, parasites in (see Linguatula tenoides and Tenia marginata). 
AVON ANCS OL PATASIIBS 2. 25 <5 2.2 Sense seewce sccan BORE aOoooSS casScOOD Ie 9 
PAGCOMNY Sle clase sacs ecece 3 BRODER ASB COC OCR COE EE OEECEEE siete heseten coos snes es 53 
A UURCEIES oat CSD CO CSRS RCC REESE EE ee ne, Uae oe SLR 53 
PRS TAT OM er E a a teg one es Sakon ae IO ee Gcimanons cend Shed cod das eens 22 
FATED LIBLONELECONICUM a noe eee tan SNe See eats See cee ee Ee eee Paes 16, 138 
Pa ORM OMIT O TSE op) See ace Mercicas us aa aren Segoe a coe 50 
Antelope a8 a. béarer of sheep: parasibes... << .sseancceecs -eecsece--oe 15 
Arrangement, plan followed in bulletin.........-...----- cddelasdaeeacsc aeee 22 
BU LUO NNT Ses SS RPE RAISE IS Ee Re A a ate samgenioseeeesacs sce. 18 
ERERESSLUUNUUTECOUICR tn, Sk Chin ak a eee ee reat a A Den a Os 16, 145, 151 
AESCHIPiMONe it. sae esee ee ce eee ea ose ce Retissccieseiavwicicior 151 
HOULES Sess ee Sapoce A ESE BEBO DOC RACE eC CELSO nar 154 
SORDID APTOS oe GEG aE Rice one ee ON Se ee 151 
PAISCOTIS! SUM anes cance aacas ces Bee eee eo seca cine ae ainic oa oe we eee acca 152 
LE TUES II ERI UBT RE hs aie ie Nee oA a SUPE oC A Ee ete 18 
{EET SVP ANTID) 7G cae Pap he ne OO SO Pete Nec ee 72 
Brain, parasites in (see Cenurus cerebralis). 
POAC HLS VELMI OLS 7 -se oo saat: ees et SNORE Sone. JS Wg Oey eee 185, 201 
Crec Unis DHOLWORIAD IN cman 20 So tes Ce! tl ee sy ek Me oe 181 
Catanchs enasaliseme cee ome me es Ne CHS) RIE iskte rhe oe et mle a9 Pavanl ana 25 
ChOMOPLESICOMMAUNISE AT MOUSE ee oe sty See ye eo eee See ae 53, 65 
COCO aaa com se ae eee ee eee ea eee ae ied Le ae Sewers 3 Yep i ly/ 
SB IETUTUSICEr CULM as aa Scare 8 ere) cn tern bk ny oe eS AEROS Co DBEe EOE 30, 72, 83 
Common scab (see Psoroptes communis var. ovis). 
WOVOLES-WOLms) IN aes poe eee ee Bee ee ere nn Mere Seep tee poy ete 14 
CSACEN CUS, GEASS oes oh ee eee a re Be ee ra Se eo ee mae ae 72 
TOUTES eee ee eee es - Sa SA Sa ES sch ae eo 88 
EM THUEGON, ses ee ao ce SoS ae ata tote car ay et eee ears 87 
Custeonr cia tenure lng cree ee ea eee acme kn ar wom ou tron da wees ononewoe Gb 72,75, 117 
TUNER oi: eye eee Some oe are ie Soca REE ds ccomece se 80, 82 
LUT SELF TO) TY Te ese 2s SR a eg 19 
Description of species; contents. of22t-.. 2-425 saecce occ ccu eee ewite shoei 10 
MANORS: Of parasiiie;diseusesices..22 0. --ccss cece ~ osc zeee we cléccusjadecnnec8 11 
Disease, parasitic, mainly due to mechanical causes......----.---------+---- 11 
Importance Of early dlagnosis..-= .<s-a- <<. -+ saess~<----s 11 
cuesiod ular. Gf Iutbehineseen eee sts Soe ce eee ok eis waxes aoe 165 
eA UMNP HBCU. <n ce echtaa eee ae ee aaa a adios ex's aduacivenna aes; LIA 197 
Geseriplioitecomceee Neca sens oe 2 Se < o ws wecsiscincen daweec 127 
GISGAsO: CAUBEOs yee care eine Cae ose saee od cceus sounds 129 
GIALNOSIBgSee ss Jam set Sac See esinis 2 Se caae's aaa > one 130 
GUTS ila ieee we eee toes rk cat out cach an chigraire 130 
: Pabligloo ge es roe ae et ose och Sake ames 131 


216° 


Page 

Distoma hepaticum, disease period of anemia... ...c0. saenes connec ce ce cones 129 

emigration...... omens « so ceeae Sena 130 

amMMioration: <<. ..-ce.sees Joo e eee 129 

loss ‘of ‘fleshisc.2- .cs25:ch oc oseee eee : 130 

PIOPNOSIS == oo hes ces asco aee eee eee See eeeeee 131 

SYMPLOMIA <n soe cen ea eee Aiescctepeeeee 399 

treatment. 2s scene ec cusere ma seel dacwis senate 133 

fipures. :scsssi toss ot eee Saws = oeeeeeodaeseee eee 136 

lepislation CONCERNING jo2ac. «= -5 = see eeesice = eeniaaee eee 134 

life*history 24. .cece nese ene cob ce cence et a eneeee ene 128 

OCCUITONCO 22. sce celiac sceeeo esos tee seer oe tee ee eee 127 

rareiin: United! Statese sto. tess s seen cicitoee setae aeeoae ie 

Distoma lanceolatwm Ane ceee ters eiet ee ee ote tomleeenle woes eee eee 16 

GesCriptiOncssoa- sae 5s saa sds sao ssl Pe HS ee 137 

ASuUres.<2--t cates ebwales tect neteotes eerie eines Cotes 140 

Dochmtus cernwuus: 2: = 22). sees eeeecs Settee eee eins 16, 17, 22, 117, 118, 142, 145, 146 

GeSCLIPtON ss. seers se Fs So eis aaa e ie Deane eeetee 155 

disease cansedbyeee ewe oe ei ee eee eee 156 

treatment. a... )cus Sees ses scecceeeeee esse SAE Soman 157 

Fi PUTOS a raiors tote fatter alolewie else Sot Sone ee aee cant oe dace 160 

lifehistoty== =-222-<2ece. cee eeee=sece 5 acietie te beee ees etemce 155 

OCCUITONGG: Aci eke cist hehe tes Li Ake ee keh eee tence tees 155 

Tockmius tigonocep nals sae 3 arta th oaleiet a) Salone eee clas ecco ereenine 156, 167 

TNH COGS rats vatale iw loaf clsielstele Meitceioein cae ae ceisie ceriseinte 155 

life historyc Actes teste test ae eet eee esine ceria 155 

Wop, as a beast of prey.----2-------- <2 422255 teesleene wees see =~e ee eeene 14 

Aas a carrier ol dancerous parasites...---.cc--s +~2--t -- =e eeieee Sack e ae 14 

Dochmius tigonocephalusin-c==-e=e seen ee See e ae eee eee seen eee 155 

Jerislation CONCERDING seo. eces-6 as semen ean eee een eee eee eee 78 
Parasites!Of, COMMON: LOMANE= cece eam ne eels aceon moe ita 14 

BH6OD%.-22- hs sciesee ease etiee se tee as cee eee 14 

relation; to sheeplhusbanany, caaeee ames eee eee ee oleae ere eee ee eee 13 

PENA CONUTUS IN 2 5+. 835-5 roe caus ce ne Sa caivan tem nome se elo we cae ames 76, 86 

TENG CUCUMENINANM wee eee a ee eee ene ereees niece = eee a selec eee 76 

GRAPH TR DLO WU aaa cancmo J50N ee onoada Dpandd upSutay comsabéocec= ~ 76,86 

TOMA SOTA Wieesces se aeeh ae cee eee eee ae eho nee onto sae tee eeer 76, 86 

Gape WOLDS TN)... 62 22 Set kt sees ae | ales ome een eee Se eee em 

INGOSHIN Ovas 5 Aci wn eae cle Sales ote et eee ae eee enema 14 

and in sheepie 252.5506 54- ete ta oon saeete oe cee a 

LIE IN NSN Na SOO Saad Soca S OC GSO RECS GOOOCO COOSUS HOSeSOeSseS o2eS09 =< 77 

PICVENbI Vea. ao - ae a Soe ene eee ree ee ae 78 

Varlebiesior, liable to imtechOneesa nese = eeecasses esse ineeer eee === 14 

Echinococcus (see Tania echinococcus). 

Embryos, conditions necessary for raising..--....----.----- ------ --22-+---- 11 

External ‘parasites .<: .o---<'=-icestaes ses <- os os eee eee = ee ee 18 

Feeding. .- 2.3 sose'vewcns seeces o> ones cnememe ees Gaeess es © <== ens eelase=ian melee 13 

BRIS ue Seale cate e nee oot ee ene cena tee cee arsine lee cle seme eielaete eee ete 127, 137 

Moot scabesace sessrest ec ccccee sccminscceele tines eee ccc lo atele aie eaten teas eetareia 65 


Gadfly (see Gstrus ovis). 
Gid (see Tenia caenurus). 
IE ea SA ee BAe a RAM Se Ste aR ORS OOOO COIS 590050 2500056 30, 38 
Goat lice (see Trichodectes climax and T. limbatus). 
Grub in the head (see (strus ovis). 
Head parasites (see (strus ovis and Tenia cenurus). 
Head scab (see Sarcoptes scabiet). 


217 


Page. 
Hoose....-- sere aecance Se anvoaies secs sacle = ssc scicise sccee seeesoscs bese ces, LooyeUl 
AUIS Ke meet te sot aie = Saber erent male wale sea obscene Salecseis cao sanesmcemes comes 185, 201 
Hydatids (see Tania echinococcus). 
MMS tra bLON Glass eee ace -oeeien siete o cama see aatideiicea boc cns see cacece sone 10 
MabeLialetOneeas see eeeeine ees Beet aus cae shaaecink am we ter bn valeaaes 10 
DON POSEL Oly ow tee re era Aen meen Sa ace he © aes rips eas nee 10 
infection, hows secured 1 6X perimentss. 32.4 cee cose chas sare csee cece uccoen 11 
Inyunvesshowseitecteduby, palaslvesen. =m cance neae caceme coe casticc sone scence 11 
Intestines sn odulardisease Olea centee ate aseaccecees sae seme ee sent aasiecee 165 
NitGhA aememese Heeeena caemnccniactes <tc cecisiscey sete on eee a eece ns Suenos 53 
INBEC US Pere oe eye rete onion wetie roe oe c Saat iow atecerme ere esa aeek ete cte 53 
Lime, parasiticide in manure...-.........-c-<. ES ES Soe ene 13 
ENGAGE LOLU CS aoe eee aie tees ch vam ae annie wale eos ae nooo ee ome 14, 16, 69 
escriptionecees . eas Gace we oe ie ae ee ere ee eect eee 69 
CISCASEIGAUSEOND Vines tes. see eee cae tee Seaeieee sree ears 69 
MIQUTCS: xcnce oe aeacas «dee. oe aes Scie SRE See eee eee 140 
PEG HISLOLY tae cG aoe cec/s fone tesla sone aaa ae eee eara aes ee 69 
MEST GULL URUINDT EL = iciake btm ihe ated aisee Sat, VAS Sew cece Oeee mele os Gren acre aae 69 
List of parasites described....-. SESSA COREE OSCE UR OC Dee CH Oen SE aeanee 16 
OXLCIN Ae PALaslLesceaeocmect Corks eae tee ois See ee on ee ee 18 
WOVeEUs PavAs liesplls er tee Atais eserves we ae Sas esteem ee Ciao wears an wae ewe meee 127 
TAI Cra UO Ue sa steer yaar oes cise na hsmeiey vat aiece Sieims a SSeS ee caae Sees caer eSeer 127 
iver duke (see, Distome Repancum) os. 2-52 cccaweaccdnsce set cececteuss =a 127 
(see Distoma lanceolatum).......------ wdcceences RAS N ane OSaae 137 
Lombriz (see Strongylus contortus). 
Louse fly (see Melophagus ovinus). 
UM aOR Seeeteters ener ores ie eisene Seok accesses cae ctismioe sens onceee 185, 186, 201 
CUASTIOSIS ES estes om see e Soom canine eee wees cee a ace ee oe eee 186 
SPE CLONE O betes t ons ape eee ee etn ae het Boe ea epeete se 185 
parasites: o meth er Olde World cece. cin satecr ais oes cree este ane nee 17 
Lyenwatenandwawhiewashinesinn 86a Dscosee ecae css nes acne aoc eee cece eeee 12 
Mallophaga ..-.- SeSSG0S G80 DEC OOO CUE ECHOICE GOO Abo ooeeeeoeearaccoe 45 
Man, parasites of, common to dog... ......--...---0. secs SCE Seo ease 14 
SHOOP Masse ce stins wesc nite ease Esmee Ce amees 16 
LUD CMWOLM Arlee terse caine se sive oo Su wee ores male wie oman sie sane on eon 14 
anUiMEsheepecevies so sioes hecwe woe ce eee oes Pp Se EE I ca 87 
RFA ERE CETL NOW OCI AOS 1) Se Cee a Gl BEcrSeSABCOs CSG006 booone caubecess 13 
economichmanagvement Ofsesee oes once See eee ae nets eee eee ee 12 
mixture of, with lime...... Ne Se aoe ccd seen se aa ees eee aeaeeee 13 
source of parasitic infection............... seme ces eee cosmos 13 
Measles, in mutton (see Twnia tenella). 
Mensunements tableswesassisss ssereccc ene sue cee eee abece eases Re eemasenicae 23 
Medical: treatm emtipeses saat ere aereet ie eas een ie eee mace ciee asin anes cures 15 
Melophague vias. 2-2. 0-22-% cneseteceecs a ne alee oe ee sae oe ciaweks a oiciatarets 16, 39 
diseasercaused Dyasee sec sewe cose een wee seocecicenereceace 4l 
CLEAGING ME mem asia see ee niece csacisse = xine See eateries Al 
expenimentstwmibhh aaa secs 5 Sess awiee ee acincciccen cease ee ee 41 
TOUTES ey seepee sae setae oaicles cclecaicis ccecicnias sievosie ote a siclele 44 
habits of yssseresses ee rae rare ter aae ai) manner ete 40 
dife history seereere apes ce Seca Se aia nice ore ee 40 
OCCULTENCO.E aes meiner aa Aaciae weeel tics sm de eins cisco cheats 41 
SOURCE? tet tes teleost sok wiadeaiaeew aa ces Secs Aecsermaes Al 
EP TIREE LCOCLIN. 22-90 oe gad 5 26a el NS Sheth ReneS es eee watieesaec tee 87 
OAH AE MmcnsE OL Nibestines 2 is eee eos lok ch be cece snacenteecevendes 165 


i et MA RELIC te tc, data oleae acide chad vans abseie vmaaeas se saca eau 25 


218 


Page. 

(Esophagostoma acutum £2. ic25- S25 se wc ones ees elec ene eee ee 168 
Cisophagostoma columbianum......----.-.-..22-20- 16, 17, 20, 21, 22, 118, 145, 161, 162 
description { - 22.0.5 5.22. oct ee ee 167 

determination of adult. 22... 25... ss2 ese 166 

disease caused: by... 2.2%... weseee seek eee eee 169 

GIB PENOSIS Kons os eee sersc seis See 172 

Pathology o6 a... case wan ba ee ee eee 169 

PIOVERBON’ 2c 22 aces sons ae eee eee 173 

GistriputioOng sc 2.c sk fern elec ek ee ee 165 


AgUres 55 us ese olive Rane lote = sont eaes ceed 7A. vOut ee 


investigation concerning ........-..------s«=ess 165 

hfe WiIstony mac. ce once mene et ease ee aceon 168 

OCCUILRCNCO: acces cace ene owe nie ese ees aonee ote 168 

CEEWUS OMB ree ete s women eae Ree ne SLR arl on So eye eee re ee 16, 17, 19, 20, 25, 85 
CESCrIPLION =< ahi 2 Soothe wae’ 28 eR ee nk ee 25 

Of MARV sot ene kc dace Sete bese eee ee eee 26 

eliects on sheep jee 24 oto eae Io eee ee 27 


AIP UTOS soe cee he Reece Say ae Rone s p eee eee Mel a aoe ee 


OCCULICNCE +: Wass cs Bee Sts tee eee ae en et ee 30 

pathology 28. 24 er Se shee. el ae ae kl en oe 28 

PECAUIMONG, 2h aoe os ooe SO ORS oo ee ane e la re 31 

SUTPICA see oo ee ck Se cc eeu ace See psoseese 33 

PAM Ct San tase ee cmt Se one ccc c/n wo Semicewit tees sane eee te REESE eee 185, 201 
RARASIbes: abun ANC a. oe on acne eee cae e See ee Ri a eee ee Lee 9 
Eira ith vance eee eee ee Remnant Rr ated tau ein, RI BSCR CO heb SaOS 17 

common wo sheeprand dope. - 45.22. <coc aeaee oo Sean eee cees eens 14 

external, definition Ob seseteee oc) coe oe eer ee Se a ae 18 
Cestructivenessizecee a cae eee ee ees Se aoe es ae ee ee 22 

how. sheep become’, infested 222. S222 22s seeee Stas eek soe eee 19 

leneth of time of development iz.. ess< c-se neo ee ene een ee eee eee 20 

LOCATION Baer Sas se ee ee ee Te 18 

OFbhie slain a. tne ees eA one ee Ee eee eee Seaeeaas 39 

season alianpearancesncas sear eee ee ee ee aps emt 21 
VEPEtable seas hear oe wry sys Ne ee ener CR eg eee 17 

Parasitic diseases the chief source of losses....-- .-.---2-00 ee--ee -enenceee ns 9 
astures, as:a SOUrCeOhanteetlonaset ceca. sane tee nee ee ee eee 13 
COFFS 01 dee eens ee eel a, a UN NM i Ne (Ay eva Res ie A ao 13 
Fentastoma dentioutatim .-sos0 oncees osc oo ee eee eel Ee 69 
TGONTASTONVG: TOENIOU AES Soe ke SS tS Soom ap Soe a eat OE cee a pa eT gee a 69 
PA GHINASIBS. o. aes fone is Satece tence etek ae cue ee a ee ees eee 39, 45 
PUSUMOHIA, WVELPMIMOUS: 5 Sac. kcoceue & cohen Selene ade ee ee ae ee ee eae 185, 186 
Peoropies communis, Var, O18 2 cc25. 218. Loe oda n ence oe ke ences <=) eee eee 16, 17, 53, 56 
disease canned Nyce. sec wac cata sebe Seen ee te eee ees 56 

@IADNOBIS. = 2 eSB ae. a tee cee eect eee 57 

difterential sss ssces ceccce cs see eereeee 59 

pathology. o22.-0<- corec scene apes eceeeeee eee 57 

PLOPNOSIO 222s cen coe cmos cod ce aaa eee eee 58, 59 

source of contarion ..2.-. ese == se eee 58 

Symptoms Of... 5. j.ccow sod scone eee eee eee esos 56 

treatment! medicinal]. s-cereneeearieeeee casa eae= 60 

Preventive. cece see eee Peas eee 56 

ficuress 232 eters. ee a ene a 66, 68 

lerislation eoncerning.¢.--..ne- oe eceear en ee eeeneee- cs 64 

Purchasing sheep, examinations in): es. fesnos poet eee e seeeeee Saceesiesee 15 


219 


Page. 

Rabbits, not infested by parasites of sheep ..... rect oorteccobLbororcccrcce 14 
Hane esas SOULCE ONT CG MOMs seme. sa ccee ieee eames easels) scams aces esa as 
SUIS «ood adoci= ce Hoe AG eed Ce Be Ce SOEs Go OCRO DOU OEICSSEEr Ceesccrore 13 
SCa Deen a) < eee ene Sa aan an eae ee acce sens toeslcncclnn= ate saa sa\- was 53 
PEN CLAMGEACE MONO eee eae eea = sealeasine clases satccae se ectooes 53 
HSE See ce omOee bcostecaoe eebece Pooktceesebo Bpoebbod SeenEeooac SeRocee 53 
lifeshistOLy cass oe ket ese eo oe eraser astecsmeeas cece escn cose 53 
Wiiie-washimoand lve Water -ss\-sueiscesce(enweles-ces -oa——< s-- = 12 

SO RCODICSSCHUICIN AT AOUIS Reem een ne nee ae aes Sons ae eanieaaialeses sci saeisicne 53, 54, 56 
(ER GIITUTON ioe cee eeSsHiGeH coe CEeOMC Ose oIsD Oooo eebae peeroocees 54 
GUSCASELCAUSCOLDYs meee een ca dts es dc ccccls oe celsceseehsnesiesce 54 

GIBPNOSIS Ses os omes cases esces sce ses no aeaclevoncsss 56 

prognosis..... fo Buin piboc SOS ne Eee IAG ECOG name 56 

BOULCO OH CONLATION | sno 02-2 io cee se scos scene Seen 55 

ELCAGMONG Saete tls cesses cnc see es sece cves cane scce 56 

ISCIECROSLOMMICOUINUNU ma eae a see ieee eerie eee ne a we co ceincceacsaicces sets <caese 161, 162 
ISCLCROSLOMCINN/ PORLONUUM Ene = ancn tame menace wae ione eloeme a oemieelata esac ccie'= 16, 145, 167, 168 
GesCHipionesas sess esos Aces oes sas ecemicess cess mecies 161 

FPUTON See Cece See eee ete one eee ee ooeeeae Paeectes 164 

MLORNISLORYS sce dcto ase rece sa Stee 2. ce soe woe eee lease = 161 

OCCHTECNCG Ges eenee een ewes onan Je co sioneciasiseecice ss 161 


ELEN OSLONTA: LEN ACUMUNUM aaron tei wn Uae bloat e bw ce ete ec cce cebwass Sac wese cee LOLSIG2 
Sheep grub (see Aistrus ovis). 


Stiecpoudmateyavaliorets css cas 22 Vek nsec cee ces ese eee 9 
Sheep louse (see Trichodectes spherocephalus). 
TeduiCerdedite Ree eee eset Sioa aat ae eee a eaten ee 45 
SGI, TORMENT CWO OS a ode Beno S COOP ONE ECDECUCOO COCCI Aiea CROCS CRE rer EIA cece 39, 45, 49 
NOUrCeSOMINLOLMatlOn- LeCOeNIMON Ole saa susan seca ses sco aee aetna cece 23 
SpeciesiabundantimeUnited Statesssc.2.-- sree -s- se ne ceee cast ec secs cose 16 
American and huropeam comparedis.c.. 2-266 oes eeee ne ea coc cose 16 
describede sa seca oe wtoncoe eb sebt ones a sactaemmssese ease cs ceee 17 
GESUTUCUIV.Oplee ae ae set enn Sten cce ce sa cicciclecicince eco nes acniascea's cosas 17 
NOME U Mibed Staveseas= = tose acces ace Me cleat ec ca a ccls esate 16 
ORexternaleparasites| 1s sce os eas bee cee cece Soe sss sce se se memeee es 16 
rarenmneUmibedyStatess sees essa secees othe ticnscse sccecelesesemisicioens 16 


Staggers (see Tenia cenurus). 
Stomach round worms (see Strongylus contortus). 


NinONGULWS CONTOTUUS == saseascaes eeecnucase Soon eeeees 16, 17, 20, 22, 117, 118, 141, 146, 202 
Cesckipmong puacik tetas set ete eet eee cae cee acee case 141. 

Piscaas CHUNG DNs eiace ce tr It de eae eo cia 142 

(GE 1211 eae ae ee ei A her CF 142 

Al oR eet fat at Sahel Ae NICS Sonne oh ce ts anaes e - 144 

Mi OvHISLOR yt etae cla oats oe ei eeroee oeteae oronees cae 141 

PheMOMDLUZ GISERSeasaoe ae see ss tame Sete ce oein oe ccc cee 141 

SERONGY CUS JUANG: oer ot el wie e eee as ale eee eee ce ccaee cone 16, 17, 20, 21, 185 
description™=-.-2er e's cs 2c See Reece osee toa teeeee 201 

GISCASO: ERUBCED Ysa soos oso s aoa atce es sek oc wens sone en sces 203 

GUPAOME sense teenie tee ee oo oe Soc sicleteaipseazele 203 

tracheal injections for....-....--. nee ae eee RES 206 

treatmentemedicals-- <2: .2 5522 5 Me se ccc ee acoue 205 

PLoveMnuive: sss 5326253... sesuseseaclnes= sees 202, 208 

APUTES. Rete eee ete as ewes kata t bes oceues etaeee ce cwes 210, 212, 214 

OCCUITONCE.-c.ce ae wane eee eed sas eas aaubenececes samc ceecee 204 


Page. 

StrOngulus TiiCOlts «. oat aeces eae ee wae oceans alee 16, 22, 118, 145, 146, 149, 202 
‘ Gescripvion.... cass 2. cscs Mec csclense Se clseute ces eeteeenrenee 146 

AP ULOS © ois wegen cote cs Aalcins cine etasa susie eosin Stree 1438 

Strongylus minutissimus in Algeria. -—-- - occ cece s hand nals oeloas eee 17 
SENON GUUS OUS=PULMONGUS wacoce soo seslace eee ee sloes soa a ae 16, 17, 20, 22, 185, 186, 201, 204 
CESCTIPTION | oo nig cc eras ace otiar elena stereo ater e te tee 186 

disease caused DY). jacse 20% tac mecedeteccemeeciete ee 187 

GiGONOGIS ho c'soae ese cle de sea el aaees Remar 187 

Patholopy srccsae cic sos estres eae cee 187 

PROGNOSIS sco s sees seeie en eae eee 187 

AOUTGEOf Infections. asses been ee lee OE ener 189 

treatment medicinal. ....-......--- paar: 190 

DPIOVENLYG 5 cease ee ees eee 189 

BOUTES oo~ se seas ce aclan se eee emeE Meee 192, 194, 196, 198, 200 

Life History <.5.s2. semncaseeei. fe saeiceeeeee sateen 186 

SNONGY ULGITUFCSCENS ASVMNONY Me eae enn seca. eee ses ee ace sae eee soe ae 17 
Strongylus VENUiCOSUS . one ceca concen se eeeccecascetotocese= 17, 22, 118, 145, 149, 202 
QeSCrIPLION ssa cce use cceace chica eemea Tote coeeeeeeeeee 149 

FIPUTCS 2 sae e ete e anon so ese e ee eee eee eee 50 

NOW -parasive Of Sheep 2. -ca-/-ceseaysseee es = oso eeeeee 17 

Slundy seces- soso sseeecee css ce vceeiet ies ee ce cece ese coscsceet ice ac eoeaeer 83 
Symptoms of sheep infested with parasites ..............-..--.-- ---- ------- 11 
ENUGACULEMIO noses coos wane eee tea core cawicicionicee cles oe Sac c area aeeer eee 89 
LONG 0G acc neva sctec cassie se Secexte che ania sega names dower ites oeee ere sooleoeees 89 
GNI HBENCAGNY eo wastes ce acu cecasae atrecetdoccscindee cocenwasiceecieae meter or 8) 
LPN CONMIPUNCLOLG saocc cae maces cose sccwsceacaee cess osesiee asite cates oaieeeee 89 
RUNG CONUPUG = Son ea Wack on cere ore noe Caen re cee eee teens 14, 16, 17, 19, 22, 72, 76, 83 
CYSUIC Hhale i essa dase ce eae oe ee eieemewelsaemee acter emmietinetae 83 

disease causedbyoc2.-s2652 eae ace ocean oe coisa ieee sete 89 

CIS ONOSIB eh. os co ee eb esabe peeks eee tees eee 85 

duration ofidevelopment=.- sce. eseces oo ee cee eee 84 

treatment: s22. 0 sso. eon cae et a aseaete eee eee ; 85 

FIPUTOR oo. owas wc tae neta usc es se new Serene eee tee eee ele 

lifezhistory: 2c). sot Ser nee ce re cee ene eee Ree ee eee een 83 

method of infection:2-c- cscs encase wont eneee eee ee eae 83 

TERRE ‘CHOUMEFING — placa cack now ens Sabace nicer teen eee eee eee ee 76 
LOMids COMMOCOCCWHA 20% Momaide Gace <nct caseae Conureusacuckenerceeetrieee 14, 16, 17,72, 86 
HIGUTOR = sace soe aoe Coole weccs soe eee e eet eee amees 83 

IN Man sno. Saceee seccSes a oth eee pen eee Ca eee oe 14 

life history. .so-c. sce seco ee ewes oe tee eet eee eee 86 

treatment coco cae oe cok oto eee et eae ae rae 86 

LONG CLNANGA wo dee cos sen cectot eee eet eees Deere Tee 16, 17, 20, 108, 113, 142, 202 
description ce scc ssee noe cee ns acini Ledee alee ee ee eee eee eee 113 

disease cansed by c-ce5- ces con eoec ee coet ee ceeeee a. <i eeeeeer 119 

Gis gnosis Sooo. cece oo ees Sees eae e eee ee eee 119 

Guration -..22 .62- ce oece coe ee Se eee ee ere eee 120 
OCCUTITONCE, - 2222 ce jee ee cece ee ek pace eee Eee 120 

PIOPNOSIN - 6 ooo siee seer een ede teesaee eee Bea peer 115 

treatment: .2..2200 has Ces ot ce ese ee eee 120 

distribution 1022-22. ceesuse uous eaee teen ees 16, 17, 103, 113 

experiments ‘with ...2257 oo eee eee 116 

figures a tess shes hie e cece eee es Cee tee eee sacia == 124, 126 


life history i22. oS 2o2 ci cae oo eee eee cen caca.s 116 


Page. 
Tania expansa life history summary ....-.....--...- oS 9emee enesiccesscesiacas 118 
CCOUBLONC Or aeiai<imi alate riniatai= cle mineral s/eisisis sicistelcie seiei pa oees eee eee 115 
MENIE MUNCIE. os See A Seas tec cack toe <5 Sfaininloafaicieeicetse neces ee a aee 16, 17, 89 
deschiptOeeses-teece Slal=\qinj=jalislo siniarajielelninwicntas seyomic estate sie eee OT 
diseasercaused: bys. esse oc boss ces oe ee esa se cote rece eae 95 
treatment, medicinals../ 2. ccfecscscen cece a ccesccene 98 
PYOVODUIVG .2 ost eeesen Seaseccse case eee 100 
CUSUTLDULIONU Seeicee csc eaten eee ne satsee eae tea ee Rue ee 93 
— CMUEEIMICNUS poets com siasae xe eee voce Aon eee Leas 103, 105, 108 
IRON pee eeiereeee an on cena ocean eae ae poBooSeecdacHSa Macc 110, 112 
investigations CONCERNING .o6 socc wes a Soe ae canieeeRue ces 90 
MFG MISCORY se Soo te cat oa BORECOBSOAA0 acouen sean oooDboUs 94 
OMVECUS OF OX PEriments,.< 5 2sces. <b ase- ac dos wecjoacleee seed 91 
OCCUTTL ONC Ose rei nietcimiaialalal iam syenistoieiel eee = sae ne era nice een ee 93 
post-mortem examinations for finding...... ..22-...222.-.-- 103 
results of experiments): J: Js 52-22: «osces/cnece sfeetn Sele tear 91 
Menta) Gland sm =eeeieee sodoonecase Sale minivja(a(nlsia\niu/ on in'ni cies sino nia sie eeicte eeisie cin anes 89 
Tenia globipunctata..... Sie eintelem cerita ateeminiae eee (ola aivinwtnin aie eine alae ciaterama eet 89 
LRG MAT GUNA namic ciate ss cncinc ces ele ssacae eos ces 14, 15, 16, 19, 20, 22, 72, 83, 86, 114, 117 
USUI MCAE E122 a re ea Rs ee IE pe Oe eS 72, 103 
MISCASC, CAURCOUDY 2. 2.5212 cee \wcce once aoa coe beteRouete coke 72,76 
CigGNORISc cs. a s5 -eosa SG0685 ASOOD SOS SOND DOSEGSSS 76 
URGALINGMUesoate ate aise cela eee canis es Sole ote.we cies = Le 
Ci HASIOTSH C1 ee et ape Ul ae ry Se ea ea 72 
ET PTTBL GS rate tie sore anne a ee a secret Mee ooo atte 80, 82 
BREMEN Wes. cess. cos ae Goaciddoedy oseend storodeedenncaase 14 
hevisl aon coucening 9" 1... 2se aw ea eoe ste coated 78 
Hie MIN Ony Or AMOl snc aceon one slo ee 2 len Phe % 
OC CWE NCC eierere eat stalayine gels oerieue te aiar a. Sten ce er Nes ce ee eee 76 
BRIE OSO S001 Cree aes Bi Sei NS RCS, ale oR oe ee Ae eo a ke es Pa 89 
UDMA NE ROLL a ee ne Veta ate ra) oy ey a Ria oe os eee ek ees 89 
Leonia plicaia, wrongly identified in sheep... --.2.----..24sene-ses0 -cceeuce. 89 
AGERE GG RUT eis Macher SOM RO ee Se a a a AON TIL Is 76, 86 
RET Ee LCNEL Brame ese Meera teense Sa REPIE SOS" cision bs ene 2h x cic ee ee ..16, 72, 87 
(UCIT ES) — Sailer ia 8 sa PR ne IT PRES RUNES i oe 88 
MIPPE DIN rete ininslatinloinlays mere) cialaininict\ anise aioeaa sees nena eae eee coe 87 
JET ONL sets ee SS RSE Ie AAR ke ear een i ee oleae a ae eseisls 89 
Tape-worm, adult (see Tenia fimbriata and T. expansa). 
disease (see Tenia fimbriata and T. expansa). 
immature (see Tenia marginata, T. cenurus, T. echinococcus, 
and 7. tenella.) 
OCCULT CNC One merci aamastetiaclaticieteccieleeine wieein{eralslslaaienar 72 
DAO OS rans aiaaee altura inseaees Stas Secne hse cke Secwenccece- 75 
in Buropean,.sheep)<-22.2252.. 2.00000 tec SOAS OOU ONE Seta Ae 89 
the: broad: 2yos.02.-a4e6 @ siwlvinie e/via\siwieisnina/Sw arise sesicnsises scicee afers 118 
HST DG) strom ete se eae eee ga be 2 89 
Tracheal injections......... DBS S [0b e500 GU OaS SaaO eNO oS Mean BeBe aeeSmsce 206 
Treatment, empirical..o.............. aheneie aciseaio a wiscle sacissessacaneceenuae 12 
DYSPIENIG co oceae eee sce oae es cies oS coeeeauccospicdd Ass gone 12 
medical, of large fgene manic ealstecics cismistelees Meese mere eee eae 12 
DTUONGCCTGUUS G[UI5 o2 ain oe cae seen cccecatscens coccce cd 16, 22, 117, 118, 142, 145, 181 
deseriphlOn eceeaa- sas deoeee ce ecole. cleneee ck eee 181 
disease and: treatmeniti-.aje--2 0.0. 2fcocbe seo. ee eae 182 


HI ULE aca nan sales esa poe a see's, oy Ue ce vale scete es cee dete 184 


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