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3 1924 084 969 934

VETERINARY PARASITOLOGY

VETERINARY
PARASITOLOGY

REGINALD H. SMYTHE, M.R.C.V.S.

CHICAGO
ALEX. EGER
IQII

VET
ae
Bis
AD
SeS
Al

PREFACE

OF late years, owing to the increased attention paid to
the study of parasitology in our veterinary schools,
there has arisen a need in our literature of a textbook,
which, although dealing more or less fully with the
more common parasites of the domesticated animals,
shall yet be concise and of a handy size. It has been
the aim of the author to fill the gap with a volume
which, while covering the course laid down for the
student, shall be at the same time of practical value to
the veterinarian as a book of reference. With this end
in view, the symptoms produced by the various para-
sites have been fully described, together with the latest
methods of treatment, and, where possible, prescriptions

have been inserted.
REGINALD H. SMYTHE.

ALBANY Roap,
REDRUTH.
November, 1910

CONTENTS

CHAPTER I
PARASITES AFFECTING THE SKIN

PAGES
Vegetable parasites—Ringworm—Ringworm in the horse—

Favus in sucklings—Ringworm in the ox—Ringworm in
the dog and cat—Diseases of the skin caused by animal
parasites—Psoric acariasis (mange)—Mange in horses—
Mange in cattle—Mange in the dog—Mange in cats—
Follicular mange—Mange in sheep—Sheep scab—Non-
psoric acariasis — Phthiriasis— Pulicide — Cutaneous
filariasis—Summer sores—Dracontiasis—Diptera affect-
ing the skin—Culicide Simuliide—Brachycera—Taba-
nide—Muscide—(€stride—Hippoboscide as 1-49

CHAPTER II
PARASITES OF THE ALIMENTARY TRACT

Vermes—Annelida—Helminthes—Cestodes—Trematodes —
Nemathelminthes — Ascaride — Oxyuride — Filariide
Trichotrachelide — Strongylide — Acanthocephala —
Parasites inhabiting alimentary canal of the horse—
Parasites inhabiting the alimentary canal of the ox—
Strongyles inhabiting the alimentary canal of cattle,
sheep, and deer—Protozoa inhabiting the intestine—
Tapeworms in sheep—Parasites inhabiting the ali-
mentary canal of the pig—Intestinal parasites of the
dog and cat .. 2% ie de Fe ae 50-96

vii

viii CONTENTS

CHAPTER III
PARASITES WHICH INVADE THE LIVER

PAGES
Linguatula—Tenia cysts—Distomiasis e a 97-105
CHAPTER IV
PARASITES OF THE RESPIRATORY TRACT
Bronchial strongyles—Parasites inhabiting serous mem-
branes—Hematozoa—Parasites of muscle and con-
nective tissue—Measles—Trichinosis—Parasites affect-
ing the eye 106-123
APPENDIX .. 124-125
INDEX 126-129

15.

21.

. LINGUATULA TNIOIDES

LIST OF ILLUSTRATIONS

TRICHOPHYTON TONSURANS 5
SaRcoPTEs Equi: DorsaL SURFACE 13
Psororpres Egut (MALE): DorsaL SURFACE - 14

. SYMBIOTES Egur (MALE) : VENTRAL SURFACE 15
AcaRus DEMODEX FOLLICULORUM 22

. HExaPpoD LARVA oF RHIPICEPHALUS ANNULATUS 34
. IxopEs REDUVIUS 35
. TRICHODECTES SCALARIS 38
. H@&MATOPINUS MACROCEPHALUS 39
Cstrus Eour 48

. LARVA OF GASTROPHILUS EQUI 57
. HEAD OF T#NIA PERFOLIATA 61
. TH&NIA PERFOLIATA 61
. HEAD oF T#NIA PLICATA 62
Heap or T#n1a MAMILLANA 62

. ASCARIS MEGALOCEPHALA 63
. OxyuURIS CURVULA 70
. HEAD oF T#NIA EXPANSA 73
. HEAD oF T#NIA ALBA 73
HEAD oF T#NIA DENTICULATA 74
HEAD AND SEGMENTS OF T#NIA FIMBRIATA - 82
TZNIA SERRATA 86

. T&nta SERRATA: Hooks 87
T2NIA MARGINATA — 89
. T#NIA ECHINOCOCCUS - go
. THNIA CUCUMERINA g2
. BOTHRIOCEPHALUS LATUS 92
. Distomum HeEpaTicuM : LIVER FLUKE 100
107

VETERINARY PARASITOLOGY

INTRODUCTION

A PARASITE may be defined as a living organism which,
for the purpose of obtaining nourishment, passes the
whole or a portion of its existence upon or within another
living organism. Parasites may be divided into two
main classes :

1. Animal parasites, or zoo-parasites.

2. Vegetable parasites, or phyto-parasites.

Of these, the latter are by far the smaller group, and
all those which affect the domesticated animals belong
to the fungi. They are a series of very low forms of
plant-life, and their common mode of reproduction is
asexual, by means of spores. The Dermatomycoses,
which embrace the three chief species of ringworm, as
found in the domesticated animals, may be taken as
the type.

Animal parasites are all obligatory at some period of
their existence, but in many the host is only required
during a portion of the life of the parasite, and so one
speaks of “ fixed parasites ’’ and “‘ transitory parasites.”
The Tzniz serve as an example of the former, as they
are unable to maintain their existence apart from their
host, while of the latter the Gstride, the bot-flies, are
typical.

Transitory parasites are chiefly confined to those
parasites whose habitat is on the surface of the skin,

or within or near the natural openings, such as the
xi

xii INTRODUCTION

mouth and nose. In other words, they are ecto-
parasites, or, as they are sometimes called, Epizoa.

Fixed parasites are chiefly endo-parasites, or Entozoa
—that is, they live in those cavities which communicate
with the exterior, such as the intestines, lungs, and
bronchi, or sometimes in closed cavities, as the blood-
vessels or peritoneal sacs. The endo- parasites are
degenerate, but possess great vitality and enormous
fertility, and are often hermaphrodite.

The majority of the Entozoa require more than one
host in which to pass their life-history, and these are
usually of different species. The host in which they

reach the adult reproductive stage is spoken of as the
“ultimate’’ or ‘‘ definitive host,’ while the former
host is known as the “intermediate host.’’ The cycle
commences with ova or larve which have gained the
exterior. These invade the ‘‘ intermediate host,’ within
which they undergo certain changes in their develop-
ment, and are then taken in by the “ ultimate host,” in
which they complete their process of development and
reach the adult stage.

As a general rule each mammal has its own particular
parasites, but some of the ecto-parasites are capable of
existence on several animals. Hence, the mange para-
sites of horses may affect man, but their vitality is
thereby greatly impaired, and they are unable to exist
any length of time away from their natural host.

Entozoa may occasionally invade a host of a different
species. For instance, Trichina of the pig sometimes
invades the muscles of man, while Bothriocephalus latus,
a tapeworm found in man, in some countries can live in
the dog.

Etiology. — The old theory which was supposed to
account for the presence of parasites was that of spon-
taneous generation, but with the advancement of science

and research, this theory has been discarded. The great

INTRODUCTION xili

majority of parasites are acquired by transmission from
other animals, either by mediate or immediate con-
tagion, though a few may be hereditary—that is to say,
transmitted to the young animal through the genital
organs of the mother. The piroplasms and trypano-
somes are examples of this method of infection. Mange
parasites and lice are transmitted by actual contact or
by mediate contagion, as from harness, grooming
utensils, or even from attendants. In the case of a
great number of parasites, ova or embryos from one
animal may be ingested by another, or, as in the case
of Hvpoderma bovis (the warble-fly), the eggs may be de-
posited on, or in some cases under, the skin of the host.

Some parasites, such as leeches, and probably some
of the Nematode worms, may be taken in with the
drinking-water.

It may be taken for granted that an animal possesses
a certain degree of immunity against parasitic invasion,
dependent upon the general constitution and state of
health, and upon the condition of the various organs.
Worms usually infest the intestines of an animal already
in low condition, and in which the intestinal tract is
already probably deranged and weakened. Ina similar
manner lice and mange Acari infest the skin of an
emaciated animal or one suffering from some chronic
debilitating disease. Tuberculous cattle in the stage
of emaciation are usually affected with lice, and it is
more reasonable to suppose that emaciation and loss of
tone afford an opportunity for the parasites to take up
their abode than that they infect a healthy animal and
produce these symptoms. It cannot be denied that in
many cases, after the invasion of the particular parasite,
the previous symptoms are exaggerated, and sufficiently
so sometimes to bring about death. Sclerostomum
armatum and S. tetrvacanthum of the horse afford good
evidence of this. :

xiv INTRODUCTION

Environment and season have a direct influence on
the prevalence and vitality of parasites. A wet season
predisposes to fluke disease, providing the locality is one
in which flukes and their intermediate hosts (L. ¢runcatu-
lata) are already present.

Effects of Parasites.—Parasites produce their effects
in various ways, according to their position and nature.
In the bowel, worms may produce anemia through
draining away blood from their host, and even per-
foration of the bowel-wall may result, with consequent
peritonitis. Flukes at the time of migration act
mechanically by blocking the bile-ducts, and so jaundice
and ascites result. Strongyles are common in the
respiratory tract of young ruminants, and produce
bronchitis and even pneumonia.

Some parasites produce toxins, which exert a poisonous
effect on their host, but these are rare. Ascaris mar-
ginata has been credited with the power of excreting a
toxin which produces fits in the dog, but this is very
doubtful, and it is more probable that the actual cause
is reflex action, set up by irritation of nerve-endings in
the bowel. Ascarides also may produce mechanical
obstruction of the bowel by grouping together into
bundles or balls.

Tenia cenurus will serve as an example of a parasite
which produces its effects by reason of the position it
takes up in the host’s body. The Cenurus cerebralis,
which is its cystic stage, exists in some part ‘of the cere-
brum or cerebellum, and thereby produces nervous
symptoms, which vary according to the exact site.

ZOO-PARASITES.
|

Protozoa, Vermes. Arthropoda.
| 2
| | | . |
Rhizopoda. Flagellata, Sporozoa. Annelida. Helminthes. Arachnida. Insecta.
|
Ameeba. Trypanosomes.
Linguatula. Acarina.
| | |
Coccidia. Sarcosporidia (Heemosporidia. Platodes. Nemathelminthes, | | | | | | |
(Miescher’s tubes). Pentastoma. Linguathla. Ixodidz. Trombidiide. reoptide. Demodecide. Diptera. Hemiptera.
Piroplasms.
| | | |
Cestodes. Tre Nematodes. Acanthocephala. Rhipicephalus, Ixodus. Sar Psoroptes. Symbiotes. Aptera.
[. ee Ih oe as i |
Treniz. Dipylidium. Anoplocephalinz. Aphaniptera. wee te Brachycera, Heteroptera. Pediculinz.
ee ee |
Distomum. Amphistomum. Gz Bilharzia. Culicidz. S Pediculidae, Ricinide.
= |
Ascaridee. Oxyuridz. Filariide. | Strongylide. Trichotrachelide. Pediculus. Phthirius. Hzematopinus.
| | | | | |
| | : , |
Filaria, Spiroptera. Eustrongyles. Strongyles. | Sclerostomes. Trichocephalus. Trichinz, Tabanide. aS Cistridz. Hippoboscidze. Trichodectes.
Sarcophaga. Lucilia.

{To face page i.

CHAPTER I

PARASITES AFFECTING THE SKIN

VEGETABLE PARASITES

RINGWORM

THE vegetable parasites affecting the skin of animals are
a series of very low forms of plant-life, and are usually
classed with the moulds. The skin diseases they produce
are grouped together under the term “ ringworm,” but
are caused by variations of the same fungus. The
differentiation between them is only marked as regards
their mode of reproduction, though each shows a prefer-
ence for some particular culture medium. They are all
parasitic fungi, and chiefly attack the epidermis, at the
expense of which they maintain their existence. Several
observers have stated that they are capable of sapro-
phytic existence, quite apart from an animal host, and
thus infection may take place without any direct con-
nection with an affected animal. It is certain that their
vitality is exceedingly great, and-they show a marked
resistance to desiccation, and various experimenters
have found that scabs or crusts will remain active and
produce ringworm in an animal after having been re-
moved from another animal for a period of from one to
two years,

The common mode of reproduction among the skin

fungi is asexual, by sporulation. The spores give rise
I

2 VETERINARY PARASITOLOGY

to much-branched filaments, known as “ hyphe.”
These intermingle and produce a matted mass, which
is known as a ‘“‘ mycelium.” Besides these, there are
other branches given off, usually at right angles, which
have a reproductive function, and which bear at their
extremity spore-cases known as “sporangia.” Each
sporangium contains a large number of minute spores.
In some cases the spore-case contains only one spore,
and is then known as a “‘ conidium.”’

A modified form of sexual reproduction is seen in the
Ascomycetes, in addition to the ordinary asexual repro-
duction. Two hyphe come together, and a process
takes place known as conjugation, and results in spore
formation afterwards. The spore-case is known as an
“ascus,” and contains eight spores, four of which would
be seen in a longitudinal section and two in a transverse
section.

There are three chief species of skin fungus seen in
our domesticated animals. These are, respectively, Tri-
chophyton, Microsporon, and Achorion.

1. Trichophyton.—The mycelium consists of fine elon-
gated tubes, showing a single contour. They may be
simple, segmented, or dichotomously branched. The
hyphz twine round the hairs, forming a whitish mass
at the roots, and also penetrate into the interior. The
result is that the hairs become rough, often split, and
finally fall out or are cut across.

The spores are spherical or elliptical, and are con-
tained inside the older segments, which they almost
entirely fill. They are so numerous as to form a chain,
and often obscure the hyphz themselves, when a scraping
is examined microscopically.

On agar-agar Trichophyton develop a green culture.
The skin fungi will grow on most media, providing a
little glucose is added. Both this variety and Achorion
liquefy gelatine.

PARASITES AFFECTING THE SKIN 3

2. Microsporon.—-In addition to ordinary spore forma-
tion within the segments, Microsporon develops lateral
reproductive branches, which bear conidia.

3. Achorion.— The mycelium consists of much-
branched hyphz, which may or may not be segmented,
and are sometimes straight and sometimes curved,
They break up into spores when ripe, and hence, when
examined microscopically, one sees between the branches
of the mycelium large numbers of triangular, round, or
oval spores. The variation in shape depends upon their
degree of development. The whole growth forms a
crust of a yellowish colour, and is in reality a pure
culture of the fungus.

In order to examine these growths microscopically,
one proceeds by scraping the deeper parts of the crusts
and soaking the material obtained in diluted liq.
potassz, in order to dissolve out the fat. The prepara-
tion is then placed on a warm slide, and stained with
lactic blue. It is best mounted in glycerin or glycerin
jelly, and a cover-glass applied.

Ringworm occurs chiefly in two forms—the Tricho-
phyton and the Achorion form, which is known as favus,
or honeycomb, ringworm. There has been much dis-
cussion as to whether these are distinct parasitic affec-
tions, or whether they both are variations of a common
type. In the skin lesions marked differences between
them are apparent, for while the eruption produced by
Trichophyton is widely dispersed and rounded in shape,
that produced by favus is yellow, and occurs in the
form of large crusts.

Predisposing Causes.—As in most other parasitic
diseases, dirty surroundings and a debilitated condition
of the host afford increased facilities for the growth of
the fungus. Old animals are less commonly affected.
Certain sheds on farms where the disease is prevalent
convey infection to each fresh batch of calves, owing

4 VETERINARY PARASITOLOGY

to the walls and uprights being used for rubbing
against, and so the disease is propagated from year
to year. Among horses, grooming utensils, more
particularly curry-combs, act as sources of mediate
contagion.

. Rats and mice suffer from a variety of favus, which
is very contagious to cats and dogs, in which the lesions
develop on those portions of the body which come in
contact with the rodents. Hence it is common to find
crusts on the paws and around the head, particularly
on the ears.

Ringworm in the Horse.

The commonest varieties met with are Trichophyton
and Microsporon. Favus in horses is rare.

The disease is seen chiefly in foals and young horses,
but older animals are not uncommonly affected. The
eruption occurs in the form of small rounded patches
on the trunk, particularly on the croup and shoulders,
and also upon the head and neck. The hair on these
first becomes erect, then matted. The parasites attack
the hairs, which break off level with the skin, and fall
out, cemented together by a scab. The bare patches
left are of a slaty-grey colour, and covered with silvery
scales. At first they are the size of a sixpence or a
shilling, but spread from the periphery, and may attain
the size of a two-shilling-piece, or become even larger
still. After recovery, the hair covering the patches is
at first darker in colour.

Several varieties of trichophytosis are seen in horses.
Trichophyton mentagrophytes affects the hair-follicles, and
so, in addition to the bare patches described, one sees
small pustules, which are quite visible after removal of
the scab. The patches grow larger than in the variety just
described, and may attain the size of a crown-piece.

Prognosis.—Trichophytosis in the horse runs a benign

PARASITES AFFECTING THE SKIN 5

course, and produces no systemic disturbance, and is
spontaneously curable, providing cleanliness is main-
tained. In dirty, emaciated, half-starved animals it
tends to remain. Trichophytosis is transmissible from
horses to the attendants, and produces serious lesions
on unprotected parts, such as the arms and face. It is
also transmissible to cattle.

Favus in Sucklings.

This is a rarer condition, and is characterized by the
presence of scabs or discs of a greyish colour externally,

Fic. 1.—TRICHOPHYTON TONSURANS,

and which are yellow in their deeper parts—that is to
say, when the surface is scratched away. They seldom
exceed 3 inch in diameter, and are confined chiefly to
the region of the head; but a few isolated crusts may
appear on various parts of the abdomen, and more
particularly on the quarters. Favus is never trans-
mitted to other animals.

6 VETERINARY PARASITOLOGY

Ringworm in the Ox.

The only variety affecting cattle is a trichophytosis,
and it rarely affects animals over one year old. The
lesions are found in the region of the head, particularly
round the eyes and on the neck and shoulders. They
assume the form of more or less rounded patches of a
silvery grey colour, ranging from r to 3 inches in diameter
in the early stages, but later become larger by conflu-
ence, until the whole of the head and neck may even-
tually be left bare. The follicles are affected at the
same time, and give rise to small pustules, which raise
the scab, and this, if removed, leaves a raw bleeding
surface exposed.

Prognosis.—Except in weak undersized calves, tricho-
phytosis is spontaneously curable, and runs its course
usually in from one to three months. It is easily trans-
mitted to the attendants, and produces much more
serious lesions. Occasionally the mouths of sucking
calves become affected, and this form is very difficult
to treat successfully, owing to its position.

Ringworm in the Dog and Cat.

Both Trichophyton and Microsporon affect the dog,
but more commonly a favus (Odspora canina). Tricho-
phytosis appears in the form of round, sharply defined
areas, usually of the size of a shilling, starting at the
head, and extending to the body, particularly to the
skin of the chest under cover of the elbows. These bald
spots are often covered with dirty grey scales, but often
there is no sign of inflammation. As a result of scratch-
ing, they may become raw, and a little blood may exude.
As they get older, the patches become lighter in colour,
and gradually revert back to the original colour of the
skin.

The variety of favus attacking the dog and cat is
known as the Achorion Quinckeanum. It affects chiefly

PARASITES AFFECTING THE SKIN 4

the tips of the ears, the paws, and the face, and is seen
more often in kittens and rather seldom in old cats,
The lesions take the form of lemon-yellow crusts, which
are at first firm and moist, but later become dry and
inclined to crumble on pressure. Their appearance is
very characteristic.

Therapeutics —In treating a case of ringworm, as
in other parasitic skin diseases, it is first necessary to
isolate the affected animals, and to provide fresh litter.
All clothing and grooming utensils should be thoroughly
disinfected.

Horses suffering from trichophytosis should have the
affected parts thoroughly washed with hot soda-water.
When quite dry, they should be dressed with para-
siticides. If the areas are small in extent, nothing is
better than ung. iodi, or even half-strength tinct.
iodi.

Formalin 4 per cent. in water, to which 5 per cent.
glycerin has been added, is useful.

Lysol, creolin, naphthol, or salicylic acid may be
used. In calves, where the areas affected are large,
a dressing composed of sulphur, combined with ol. picis
and an alkali in oil, is best, such as the following :

B Sulph. flores. .. or ay .. 3iv.
Liq. potasse .. be a .. Bij.
Ol. picis me ae = .. Bij.
Ol. rapii ie me ad O.j.
M. Fiat lin.

In dogs and cats preparations of iodine are probably
best, and care must be taken to prevent access to mice
and rats, which may have introduced the disease.

The treatment of favus is similar to that of trichophy-
‘tosis. The crusts should be first removed, and the
affected areas well washed, after which any of the para-
siticides mentioned may be used. In treating ringworm
it must be remembered that the patches extend from

8 VETERINARY PARASITOLOGY

their edges, and hence the dressing used should be
applied beyond the apparent margin.

The most hopeful sign of recovery is the appearance
of a smooth crop of fresh hair.

DISEASES OF THE SKIN CAUSED BY ANIMAL
PARASITES.

PSORIC ACARIASIS (MANGE).

Mange is the name given to that condition of the
skin produced by the presence of mange-mites, which
belong to the Acarina.

It is a very contagious disease, as the parasites can
leave the host and pass on to another animal with ease.

The Sarcoptide are small round or oval parasites,
with a striated cuticle (usually transversely), and the
majority are barely visible to the naked eye. When
adult, each possesses four pairs of legs, composed of
five segments, and terminating in suckers, used in walking
as prehensile organs, and known as ‘‘ambulacra.”’ They
are each carried on a stalk, known as the “‘ pedicle.” In
addition, there is usually a long bristle at the end of each
terminal segment. The body is short, thick, and non-
articulated, the head, thorax, and abdomen being united
together into one piece. The head bears a projection
known as the “‘rostrum.” This is the buccal organ, and
is composed of two prominent trophi, the jaws being
scissor-like in some, and serrated, or even arranged in
the form of stiff bristles, in others. They have no eyes.

The males are less numerous and smaller than the
females. Many varieties bear copulatory suckers on
their posterior extremities.

Life-History.—The mange parasites pass their lives
either on the skin or in burrows made beneath the
surface. The ovigerous female lays from twenty to

PARASITES AFFECTING THE SKIN 9

twenty-four oval-shaped eggs in one batch, each con-
taining an embryo, just visible when examined micro-
scopically. About a month after the completion of this
function the female dies. Ina week each egg hatches out
a larva, which possesses only six legs, and hence is termed
the “ hexapod larva.” It possesses no sexual organs.

In its turn the larva becomes a nymph, with eight
legs, but is still asexual: but in a few more days it
develops generative organs, and becomes a sexually
adult parasite. The whole process, from the egg stage
to the adult, takes about three weeks.

The males crawl about, and each, after fertilizing
a number of females, dies in about six weeks. The
mange parasites can exist away from any animal host
for a period of from two weeks to two months.

Rugs and grooming implements remain infective for
three weeks or longer, but on damp walls and partitions
the parasites may remain active for two months. In
warm surroundings and in sunlight they become more
active.

There are four chief varieties of mange parasites, viz. :
Sarcoptes, producing sarcoptic mange ; Psoroptes, pro-
ducing psoroptic mange ; Symbiotes, sometimes known
as Chorioptes, producing symbiotic or chorioptic mange ;
and Demodecide, producing follicular or demodectic
mange.

1. Sarcoptes.—These are the smallest of the mange
parasites, and are burrowers—that is, they live beneath
the surface of the skin in tunnels, which they bore out.
They usually reach the rete Malpighii, where they live
on lymph.

The body is rounded, as is also the rostrum. The
legs are short, and bear simple unsegmented long
pedicles. These are absent in the third pair in the
male, and in the third and fourth pairs in the female.
The posterior two pairs of legs are ventrally placed and

10 VETERINARY PARASITOLOGY

hidden under the body, so that from the dorsal aspect
only two pairs are visible.

2. Psoroples.—These are comparatively large oval-
shaped parasites, just visible to the naked eye when
viewed against a black background. The legs are long,
and all are visible from the dorsal aspect. The suckers
are carried on long trumpet-shaped_three-jointed
pedicles, and are absent in the female on the third pair
of legs and in the male on the fourth pair. The rostrum
is long and conical. The posterior extremity of the
male bears two triangular abdominal prolongations,
each of which bears five bristles. These are the copula-
tory suckers, and are absent in the female.

3. Symbiotes. — These, again, are oval in shape.
The legs are long and thick, but the posterior pair is
poorly developed and placed ventrally,so that,on viewing
the parasite from the dorsal aspect, only three pairs are
visible. The suckers are carried on short, broad,
unsegmented pedicles.

The rostrum is short and is broader than long. The
male carries square abdominal prolongations, each
bearing five bristles, and in the female these are rep-
resented by two short cylindrical projections. The
Symbiotes show a serrated edge, and the body is usually
mapped out by broad lines, which extend from the
proximal margins of the legs.

4. Demodecide.—These will be described when dis-
cussing follicular mange in dogs (p. 21).

Symptoms and Diagnosis of Mange.—The first sign
of mange noticeable in any animal is a hyperemic
condition of the skin, accompanied by the usual signs
of skin irritation, such as scratching and rubbing the
part. Gradually the hair is lost and the epidermis
becomes thickened, and a collection of scales may appear
cn its surface. The desquamated epithelium soon
becomes caked together by exudate and blood into

PARASITES AFFECTING THE SKIN Ir

crusts. Pruritus becomes more intense, and, unless
treated, the animal may lose condition through the
continuous irritation and loss of rest. To diagnose with
any degree of certainty a microscopical examination
must be made, and the parasites discovered.

The method of procedure is as follows : Find a recent
lesion which has not been dressed with a parasiticide,
remove all scabs, and scratch the surface exposed with
a scalpel until bleeding is produced. It is advisable,
some while before commencing, to have the animal
stood in sunlight, as this increases the activity of the
parasites, and brings them nearer the surface. The
scales of epithelium, portions of hair and_ blood,
thus procured are placed in a shallow watch-glass,
covered with a little diluted liq. potasse, and allowed
to stand for about five minutes, in order to dissolve the
fat. The scrapings are then placed on a glass slide as
thinly as possible, and covered with another of the same
thickness. The two slides are then held between the
finger and thumb of each hand, and each is gently moved
about upon the other. This distributes the epithelial
scales, and on examining with a 1-inch objective, there
should be little difficulty in detecting the parasites, if
present, in the scrapings. Time and a great deal of
patience are necessary, and care must be taken to scrape
deeply, more especially when examining for Sarcoptes.
If the scabs are exposed to strong sunlight for an hour
before examining, the mites will come to the surface,
and are more easily demonstrated.

In the case of Acari in the external ear, it is only
necessary to treat the wax obtained as described.

The presence of the Demodex folliculorum is not
difficult to demonstrate, providing a fresh pustule is
discovered. This should be pricked with a fine needle,
and the contents squeezed out and placed on a glass
slide. No alkaline treatment is necessary.

12 VETERINARY PARASITOLOGY

Predisposing Causes, etc.—Mange arises from con-
tagion, which may be either mediate or immediate.
The condition of the animal and its environment have
a great influence upon the chances of contagion, and
upon the severity and duration of the disease.

Army horses, under ordinary conditions, become
affected with mange, with usually mere reddening of
the skin. The symptoms rarely last more than a few
days under these circumstances.

Mange in Horses.

Three forms of mange affect horses—viz., sarcoptic,
psoroptic, and symbiotic. Of these, psoroptic is the
most common, and symbiotic the least. Sarcoptic
mange offers the greatest difficulty in treatment, as the
mites burrow and are little affected by parasiticides
smeared on the surface. :

Sarcoptic Mange in Horses.—In horses the parasite
is known as the Sarcoptes equi, and is extremely
small. This form of mange principally attacks the
trunk, more particularly the shoulders, neck, withers,
and that portion of the body covered by the saddle.
It then extends on to the quarters, and the patches
may increase in size until the whole of the trunk is
covered. It avoids the limbs and those parts covered
with long hair, such as the mane and tail. It begins as
small patches, which gradually increase in diameter.
The areas are denuded of hair, become irregular in size
and shape, and exhibit a greyish or pinkish surface,
almost completely covered by a scab, usually thin and
composed of dried blood and exudate. Occasionally
the parts may bleed from rubbing. The skin becomes
thickened and may crack, and, as a result of infection,
pus may appear in the fissures. It is most commonly
seen in horses in low condition and during emaciation
resulting from various causes, but it may attack

PARASITES AFFECTING THE SKIN 13

healthy, well-nourished animals; but in this case the
natural defences are stronger, and so the disease is com-
paratively easy to eradicate.

Sarcoptic mange in horses produces symptoms of great
skin itching, especially when the animal is exposed to
sunlight and during the night. Ifthe parts are scratched
with the fingers, the horse shows symptoms of apprecia-

Fic, 2.—SarcopTes Egu1: DorsaAL SURFACE.

tion by smacking the lips together and nodding the head,
and these signs were formerly considered diagnostic of
the disease.

Diagnosis is verified by the discovery of the parasite,
but as this is merely a matter of chance, and may
require many hours’ patient searching, it is but seldom
that the practitioner exceeds a naked-eye diagnosis.

14 VETERINARY PARASITOLOGY

Prognosis should be guarded, as the disease often
resists treatment, and relapse is very common. It is
extremely difficult to impress upon owners and stable-
men the necessity of absolute disinfection of harness,rugs,
and grooming utensils, and the prevention of reinfection.

\

Fic, 3.—Psoroptes Equi (MALE): DorsaL SURFACE

Psoroptic Mange in Horses.—The parasite responsible
is the Psoropies communis, var. equi. This form of
mange attacks sheltered positions, as the mane and tail,
the intermaxillary space, the breast, sheath, and inner
side of the arm and thigh. It does not extend below
the knees and hocks, but may occasionally occur on

PARASITES AFFECTING THE SKIN 15

the withers and back. It is transmitted from horse to
horse. It produces intense pruritus, and the animal
rubs the parts, and may produce serious sores. The

xe
ey

Fic, 4.—SYMBIOTES Egur (MALE), VENTRAL SURFACE.

parasite lives on the surface, and is more easily dis-

covered.
Symbiotic Mange in the Horse. —- The Symbiotes equi

16 VETERINARY PARASITOLOGY

confines its attacks to the legs and feet, chiefly to the
pasterns and fetlocks, and up as far as the knee and
hock. Its progress is very slow. The skin becomes
denuded of hair, then thickened. Fissures appear and
discharge, and the exudate runs into the cracks and
dries into scabs. The entire skin over the part takes
on a wrinkled leathery appearance, and, owing to
irritation, serious sores may be produced from rubbing.

The symptoms of violent skin irritation are shown by
stamping the feet, jerking up the limbs, often in a manner
simulating “ shivering,” and rubbing the part with the
opposite foot. It may be mistaken for grease or the
condition known as mud-fever, but the intense pruritus
characteristic of symbiotic mange and the presence of
the mite are sufficient to verify the diagnosis.

Treatment of Mange in the Horse.—In psoroptic, and
more particularly in sarcoptic, mange the horse should
be scrubbed all over with warm soda-water, followed by
a weak solution of any creolin preparation. This should
be rinsed off with clean water, and the horse scraped
down and allowed to become thoroughly dry.

One should next proceed to dress one half of the body,
supposing that the disease is well advanced, with a
suitable parasiticide, such as the sulphur, tar, and alkali
dressing, of which the prescription was given when re-
ferring to the treatment of ringworm in calves. This
should be left on for four days, when the horse should
be washed again and the other half of the body treated
in a similar manner. To complete the process, the
horse must be thoroughly washed again with hot soda-
water, and all the grease removed.

The dressing should be applied with a brush, such as
an old dandy, and thoroughly rubbed in, not simply
smeared on.

Among other dressings which may be used is the
so-called Vienna liniment :

PARASITES AFFECTING THE SKIN 17

B OL. picis
Sulphur nig. # 3 past
Sapo. mollis 3
S.V.R. .. . 4a 2 parts

M. Fiat lin.

This dressing is not as satisfactory as the one previ-
ously mentioned, but is less objectionable, as it is non-
greasy and easily washed off.

Lysol, creolin, creosote, and chinosol, are efficacious
in suitable dilution, but need to be frequently applied.

Symbiotic mange yields to similar treatment, but it
is unnecessary to wash above the knees and hocks in
most cases, and any of the dressings enumerated may
be applied.

Mange in Cattle.

Sarcoptic mange in cattle is of very rare occurrence.
Psoroptic and symbiotic mange are not uncommonly
met with.

Psoroptic Mange in Cattle-—This form of mange affects
the root of the tail, and extends up the rump and on to
the croup. Occasionally it affects the fore-part of the
body, as the withers and neck. It usually occurs in
cold weather, when the animals are housed, and rarely
in cattle at pasture. It is somewhat difficult to diagnose,
as it bears some resemblance to eczema and other skin
diseases. It is contagious only from ox to ox.

Symbiotic Mange in Cattle—Symbiotes bovis attacks
cattle in the neighbourhood of the perineum, and espe-
cially around the anus and the anal fossa. Eventually
it extends to the inner surface of the thighs, and may
even spread along the back. The lower portions of the
limbs, as the fetlocks and pasterns, are fairly common
seats of the disease. It seldom affects animals which
are kept under hygienic conditions, and which are in
good health.

Treatment.—Any of the common dressings, as previ-
2

18 VETERINARY PARASITOLOGY

ously described, may be used. The following is of great
service in any animal in which the patches are localized
and not of great extent :

Kk Formalin (formaldehyde 40 per cent.

sol.) .. MXXX.
Glycerin in de na aco Bis .
Aqua ad 3xij.

M. Fiat lotio.
Sig... To be applied once or twice daily.

Mange in the Dog.

The three varieties of mange which may occur in the
dog are sarcoptic, symbiotic, and follicular mange.

Sarcoptic Mange in the Dog.—This form of mange in
dogs is due to the attacks of Sarcoptes squamiferus. It
may affect any portion of the body, but usually appears
on the head, especially the ears, the lower surface
of the body, and along the back, near the root of
the tail.

The first sign is the appearance of red patches, usually
small at first, which the dog constantly rubs. The skin
on these patches is red and inflamed, and shows on
careful examination small papules and sometimes
vesicles, and the general appearance is not unlike that
of eczema. The hair is shed, and the skin then becomes
thickened and covered with a grey scurf, and in some
cases shows wrinkling. The disease quickly spreads,
and in a few weeks the whole body may be involved,
and the dog becomes emaciated and anemic. Sarcoptic
mange must be distinguished from follicular mange, from
eczema, and from areas which have been bitten by fleas
and scratched by the dog until they have become
hairless and sore.

Eczema starts more often along the middle line of the
back, on the sides of the neck, and between the thighs.

PARASITES AFFECTING THE SKIN 19

It shows more vesicles than mange, and usually there is
more serous discharge. It is non-infectious. No para-
site can be found, though it is a matter of difficulty to
find the Sarcoptes under any circumstances, owing to
the depth to which they burrow. Moreover, dry eczema,
except when it has become chronic, yields more readily
to treatment, and its appearance on the dog is usually
much more rapid than in the case of mange.

Mange in Cats.

The Sarcoptes minor, which attacks the cat, is, as its
name implies, very small. It is distinguished by the
presence of numerous bristles along its dorsal aspect, and
the anus is remarkable in that it opens on to this surface.

The favourite situation is the head, and less commonly
the limbs. The feet and paws often become affected
also, from scratching the affected areas. The eyelids
become denuded of hair in the majority of cases, and
the skin over the whole area is much wrinkled. The
cat frequently shakes the head, and constantly rubs
against hard objects. Emaciation quickly sets in, and
death may result.

Treatment of Mange in the Dog and Cat.—It is abso-
lutely essential to disinfect and destroy all bedding,
rugs, etc., upon which the affected animal is accustomed
to sleep ; otherwise a permanent cure is impossible.

In treating terriers and the larger dogs, a soda-bath
should first be given, and, when thoroughly dry, one
half of the body should be dressed with the oily mixture
previously described. In from four days to a week the
dog should again be washed, and the other half dressed,
and in the course of another week all grease should be
removed by a soda-bath. Cure in most cases should
then be complete. Unless the dog is kept out of doors,
ol. picis and oily dressings are objectionable. The

20 VETERINARY PARASITOLOGY

ol. picis may be replaced by ol. tereb., or by tinct. iodi,
and soap may be substituted for oil—viz. :

BR Sulph. nig... es os .. Bij.
Liq. potasse .. oe o7 .. 58s.
Ol. tereb. 2s ig ee .. 5vj.
Sapo. mollis .. oe ei .. BUSS.
SVR. 5s a ais oe .. Bij.
Aqua ae si e2 ad $viij.
M. Fiat lin.

Creosote, carbolic acid, and tar dressings must not be
used on smail dogs, and only with caution on the larger
breeds, and must be avoided altogether in the case of cats.

Chinosol, lysol, and iodine are safer, but precautions
must be taken against licking off the dressing.

In cats sulphur ointment is most useful, but only a
small portion of the body should be covered at one time
with any greasy dressing.

Symbiotic Mange in Dogs and Cats.—Svmbiotes auricu-
larum confines itself to the inside of the ear. The para-
site produces a great variety of symptoms, some of
which arise from irritation and some as the result of
nervous reflexes, while others may be ascribed to changes
in the ear, such as abscess formation.

The most characteristic symptoms are flapping of the
affected ear or ears, shaking the head, and rubbing the
ears against hard objects. Often the head is carried to
one side.

In other cases epileptic fits result from the irritation
produced, and on several occasions cases have come to
our notice in which the dog continually turned somer-
saults along the ground, and this, in fact, seemed the
only mode of locomotion. When deeply seated, the
Symbiotes may be responsible for the formation of
abscesses, which may account for the aggravated symp-
toms just described. The abscesses develop in the
middle or internal ear, with accompanying loss of

PARASITES AFFECTING THE SKIN 21

equilibrium and inco-ordination of movement. The
ear, On examination, may present a fairly normal ap-
pearance, but more often shows a deposit of dark-
coloured sticky wax.

If this is thinly smeared over a glass slide and ex-
amined microscopically, often quite a number of para-
sites may be seen moving across the field.

Treatment.—This consists in first cleaning out the ear
with cotton-wool soaked in dilute spirit. The following
dressings are suitable for application :

B. Creosote ut on me eas TEX,
Ol. caryoph. .. a3 oe -. MXv.
Ol. olive aa .. ad 3ij.
M. Sig.: Pour a few drops into the ear r twice daily, and apply
massage.

Nocard advises the following :

R Beta-naphthol eu ae -. I part
Ether meth. .. s ea .. 3 parts.
Ol. olive ae fe an -. 10 parts

Friedburzgher and Fréhner recommend equal parts of
Peruvian balsam and glycerin.

Ear-cones, with a basis of cacao butter, and contain-
ing zinc sulphate and ext. belladonne vir., are very
useful. ‘

If nervous symptoms are marked, nerve sedatives, as
pot. bromid., strontium bromid., or chloral hydrate,
should be employed in addition.

Follicular (Demodectic) Mange.—-This disease is com-
mon in dogs and cats, especially in large towns, and has
also been observed in cattle and pigs, but in these is
comparatively rare. Demoder folliculorum, the causal
parasite, is of common occurrence in the skin of man,
but without producing symptoms. The parasite is a
representative of the Demodecide, which, like the Sar-
coptid, are a division of the Acarina.

22 VETERINARY PARASITOLOGY

It is a very degenerate parasite, is oviparous, and
goes through a life-cycle similar to that of the Sar-
coptide.

In shape and general appearance, especially when
viewed under a low power, the parasite much resembles
a maggot, though when closely observed
the differences in structure are obvious.
It is about ;4, inch in length.

The head is rounded from side to side,
and is somewhat longer than wide. It
carries two pairs of jaws, placed one above
the other. The lower pair, or maxilla,
act somewhat like a pair of miniature
tongs, and grasp the substances which
the upper pair or mandibles masticate.
In addition, the head bears a pair of
feelers, which are finely segmented, and
there is also present a structure known
as the oral valve. The eyes are two
in number, and are situated laterally.

The body consists of a thorax and
abdomen. The thorax is the widest por-
tion, and bears four pairs of short three-
jointed legs. The abdomen is triangular,
the base being formed at its junction
Fic.5.—Acarus With the thorax. It shows a dark area
Demovex For- about its centre, supposed to represent
TicororuM. viscera. The whole length of the body
is transversely striated, and the edges
are correspondingly notched. In the
hexapod larva and nymph stages the parasite has only
small tubercles, in three pairs, in the place of legs, and
the body shows no transverse striation.

The Demodex inhabits the sebaceous glands of
the skin, and one gland may contain from only 4
few up to a hundred or more parasites. The number

if

Up ava

AY "ee

HM

Highly magni-
fied.

PARASITES AFFECTING THE SKIN 23

present determines to some extent the symptoms pro-
duced.

Symptoms in the Dog.—-There are two types of fol-
licular mange commonly seen in the dog :

1. Pustular type (see also Appendix I.).
2. Squamous type.

Follicular mange usually begins at the head, in the
neighbourhood of the eyes, and extends to the ears,
sides of the face, and forehead. It then appears on the
feet and legs, especially inside the elbows, and gradually
extends over the whole body. The first symptom
noticeable is the presence of patches denuded of hair.
The skin is hot and usually of a peculiar purple tint.
Its surface shows a varying number of small papules
and pustules. As the patches increase in extent, the
skin thickens and becomes puckered into folds. These
are most apparent on the head, and are especially
noticeable in bulldogs, in which the skin becomes one
mass of wrinkles. The bare patches now take on a
dark slaty-grey colour, and the skin emits a most
unpleasant penetrating doggy odour. If the pustules
are squeezed, a small core of pus escapes, and this, if
examined microscopically, is found to contain a large
number of parasites. There is very little pruritus, and
the dog seldom scratches, but more often shakes the
body (formication), very much as a dog does when
leaving the water. The skin becomes dry and fre-
quently cracks, leaving fissures, from which a small
quantity of blood may ooze. It is not uncommon to
find one side of the head much swollen in an advanced
case from subcutaneous cedema. This is more often
observed in bulldogs.

In the squamous type of the disease there are few or
no pustules. The eyelids are most commonly affected,
especially in Poms and small dogs, but the whole body

24 VETERINARY PARASITOLOGY

is frequently attacked, and becomes denuded of hair.
It assumes the same dark slaty-grey colour as in the
pustular type, and is hot to the touch. Itching is very
slight. The surface of the skin is dry and covered with
desquamated epithelial scales. The absence of pustules
is probably due to the fact that the parasites in this type
of case are few in number in each sebaceous gland, and
the inflammation set up is not sufficiently intense to
cause pouring out of exudate and escape of leucocytes,
and so pustules are not produced. In both types of
the disease the animals appear wretched, become very
emaciated, and often die.

In the cat the eruption is similar, but it is more
frequently confined to the head.

Symploms in Other Animals—In cattle the skin
covering the whole body may be affected. The erup-
tion takes the form of pustules about the size of a pea,
but it is stated that cattle spontaneously recover from
the disease.

In pigs the Demodex is much broader than the
Demodex jolliculorum of dogs, and the pustules they
give rise to show a great tendency to become confluent,
and so large swellings are produced. They attack the
head, snout, and lower surface of the body.

Prognvsis.—This must be considered unfavourable,
especially if the disease has been existent for any length
of time. It is usually the case that, when one portion
of the skin is apparently cured, the disease breaks out
again in some other part, and although months may be
spent in treatment, little benefit may result.

Treatment.— Among the commonest agents employed
are the following: Sulphur, tar, iodine, potassium sul-
phurata, zinc chloride, Peruvian balsam, ung. can-
tharides, sublimate ointment, creolin, etc.

i. In early stages, when the patches are few in
number and of small extent, it has been thought ad-

PARASITES AFFECTING THE SKIN 25

visable by some observers to cover the affected por-
tions of skin with an agent which will exclude air, and
so destroy the parasites. Collodion containing an anti-
septic, such as acid salicylic or iodoform, has been used,
and it is claimed to have been very successful.

A solution we have found particularly useful in these
cases is the following :

B Iodi resublim. oe 8 sa Bye
Pot. iodid. 3 st Be s4 “OJe8S:
Hydrarg. biniodid. .. as es ©6585.
S.V.R. .. ai an sa og: Oe
Aqua ad 3iij

M. Fiat lotio. _

This is applied once daily with a brush until the
part becomes sore, when it is applied on alternate
days.

A lotion containing 4 per cent. formalin in glycerin
and water will often effect a cure when the area affected
is small in extent.

2. When the disease is more advanced, a course of
treatment with the oily dressing previously described
will often effect a cure, providing that the two separate
halves of the body are thoroughly dressed.

Another method of treatment recommended quite
recently is the internal administration of pot. iodid.,
combined with inunction of the skin with white precipi-
tate ointment, with the idea of producing iodide of
mercury in the skin as the pot. iodid. is excreted. We
have seen little, if any, benefit accrue from this line of
treatment.

Hunting and Duguid’s dressing is frequently em-
ployed—viz. :

RB Creosote ae ass a os ai.
Liq. potasse .. a 4a .. Bi.
Ol. olive : -. ad Oui.

M. Fiat lin.

26 VETERINARY PARASITOLOGY

Mr. Gray recommends an ointment composed of
salicylic acid, 1; gum styrax, 1; sulphur, 1; lard, 9.

The styrax causes this composition to penetrate well
into the skin, and it is decidedly useful.

Whatever treatment be adopted, the skin should be
first washed and well kneaded with soap and water, and
as many pustules as possible squeezed out. The dressing,
when possible, should be applied with a good deal of
friction.

The general condition must be attended to, and arsenic
in some form should be given in combination with
laxatives.

Sarcoptic Mange in the Pig.—This variety of mange
first attacks the head, especially in the neighbourhood
of the orbit and ears. The inner surface of the thighs
is a common seat, but the whole body may eventually
become involved.

The affected areas become covered with silvery-grey
scales of a considerable thickness. ‘When removed, the
skin appears very much thickened and inflamed, and
often shows wart-like elevations, which are in reality
hypertrophied papille.

The Sarcoptes suis is one of the largest of the mange-
mites, and the females may measure $ millimetre in
length, and hence be visible to the naked eye.

Treatment.—-Sulphur and tar dressings in oil are
usually quite efficacious.

Mange in Sheep.

All three varieties of mange are found in the sheep,
but of these the psoroptic type, which gives rise to
“ sheep scab,” is the most important.

Sarcoptic Mange in Sheep.—The Savcoptes ovis con-
fines itself to those portions of the body which are

covered with hair, and seldom attacks parts which bear
wool.

PARASITES AFFECTING THE SKIN 27

Its favourite seat is the head, particularly the upper
lip, sides of the cheek, and ridge of the nose. The ears
are less commonly affected. The disease may extend
down the breast in a bad case. The skin shows a large
number of vesicles, which burst and discharge a fluid,
which dries into yellowish crusts. Pruritus is intense,
and the sheep constantly rub their heads against the
ground, trees, posts, or their neighbours. The scabs are
thus torn off, and the bare patches bleed, and crusts of
congealed blood are left on the face. Conjunctivitis is
not an uncommon sequel, and may be followed by
purulent ophthalmia and blindness. The sheep lose
condition and may cease feeding, while the wool is
rendered useless.

The disease is very contagious, and so isolation is a
matter of great importance, and care must be taken in
parts where the disease exists not to introduce affected
animals into a clean flock.

Treatment.—The scabs must be first softened with
alkalis, such as liq. potasse, mixed with oils or fats.
This dressing must then be washed off, and one of the
following parasiticides applied: Infusion of tobacco,
sulphur ointment, creolin solution, or diluted tincture of
iodine. The simplest and most efficacious is the sulphur
turpentine and oil dressing previously mentioned.

In this country ‘‘ head mange”’ is not a scheduled
disease.

Psoroptic Mange in Sheep (Sheep Scab)—Etiology.—
The cause is the presence of Psovoptes ovis in the
fleece. The parasite is usually conveyed to the sheep
by immediate contact with one previously affected ;
but as sheep have been known to contract the disease in
places where there have been no flocks kept for as long
as one or even two years, it is probable that the parasite
is able to live for some considerable time apart from
the host. It is certain that the mites can retain their

28 VETERINARY PARASITOLOGY

vitality on a cast-off scab for a period ranging from
one to two months, providing that the scab is kept in
a moist situation.

The parasite is quite visible to the naked eve, es-
pecially when viewed against a dark background, and
if exposed to the rays of the sun.

The length of the adult male parasite is about $ milli-
metre, or +; inch, while the female is rather larger.

Crows and other birds which perch on the backs of
sheep have often been accused of spreading the disease,
and there is no reason to believe that this theory is
incorrect.

Symptoms.—Psoroptic mange may attack sheep of
any age, but the members of the flock which usually
show the earliest and most serious symptoms are lambs
and yearling lambs, with fine, supple skins.

Some breeds of sheep seem particularly predisposed
to scab, though lack of condition plays a far greater
part.

Unlike sarcoptic mange, it is the parts most thickly
covered with wool that become attacked, such as the
neck, withers, back, and sides. The first symptom
noticeable is intense pruritus, and the animals constantly
scratch and rub the affected areas. The fleece becomes
matted, much stained from scratching, and in many
places it is torn out in the attempts of the animal to
allay the itching. These symptoms are especially
evident if the flock is driven, when the sheep so affected
constantly halt and rub the bare patches. If one of
these is gently scratched with the finger, the animal
evinces signs of great satisfaction by nodding the head,
smacking the lips, and wriggling the hinder parts of the
body.

If the fleece is parted at this stage, the underlying skin
will be seen to be intensely inflamed and covered with
numerous yellowish-white papules. These go through

PARASITES AFFECTING THE SKIN 29

the vesicular and the pustular stages, and finally burst,
allowing the escape of a sticky yellow exudate with
an acid reaction, which soon dries into a scab. This
scab grows in area, as the parasites now leave the centre
and proceed to the margin, where they once more attack
the skin, producing a fresh crop of pustules, and eventu-
ally a fresh scab, which becomes confluent with the
original one. The large crust thus formed has the
appearance of dirty parchment. It drags out the
fleece by which it is attached, and becomes raised from
the skin. It then begins to show fissures, and is finally
lifted off by the crop of new wool which grows beneath it.

The surface of the body thus shows several different
appearances. We will suppose that in a typical case some
portions, such as the rump and the under surface of the
body, are covered with sound normal wool. On the neck a
recently affected patch shows matted, tangled wool and
pustules beneath it. On the back we may see a parch-
ment-like scab lifted off from the body, and close beside it
an area of dry, thickened leathery skin, covered with
desquamated epithelium, and in parts showing traces of
a new growth of wool.

On the sides where the sheep has been able to bite
and scratch we may see an ulcerated patch, showing
signs of sloughing or local necrosis.

Diagnosis —1. There should be no difficulty in dis-
tinguishing psoroptic mange from sarcoptic. The latter
attacks the head, while the former seeks only parts
covered with wool.

The parasite in psoroptic mange is not difficult to
discover. A portion of scab should be taken from the
periphery, softened in diluted liq. potasse, well teased
out, and examined microscopically.

2. Rain-Rot.—This is really a sebaceous folliculitis,
occurring in autumn, after excessive rain, and may
affect many members of a flock at one time. It is non-

30 VETERINARY PARASITOLOGY

parasitic, and there is little pruritus. The wool often
falls out in patches, but the typical symptoms of scab
are absent.

3. Phthiriasis—Trichodectes are found around the
point of the shoulder, and could be only with difficulty
confounded with Psoroptes.

4. Sheep are sometimes the subjects of an ecthyma,
which is seen on the inside of the elbows and between
the thighs, but this could scarcely be confused with
scab.

Treatment.—This must be divided into preventive
and curative.

Preventive treatment comprises the prevention of
primary infection and of infection of the rest of the flock
after the disease has appeared in certain members of it.

As sheep scab is a scheduled disease, the Board of
Agriculture lays down a series of regulations, with the
object of preventing and stamping out the disease.

The Sheep Scab Order of 1905 is the last issued, and
its provisions, in brief, are as follows :

All suspected cases must be reported to the police,
who call upon a veterinary surgeon to verify the
diagnosis. The premises on which the sheep are kept
are disinfected and the sheep dipped. It is illegal to
expose infected sheep in a market for sale, and no sheep
are allowed to be removed from the scheduled area
without a licence. In districts where the disease is
prevalent dipping of all sheep is made compulsory, and
every owner of sheep is compelled to send in a return
of the number he possesses.

Before an owner can remove sheep from the scheduled
area, he must produce an order, showing that they have
been dipped satisfactorily, within a period of twenty-
eight days from the time at which he wishes to remove
them.

In districts where the disease is prevalent the farmer

PARASITES AFFECTING THE SKIN 31

should carefully dip all new sheep purchased or brought
from another farm before introducing them into a clean
flock. Isolation is a matter of the gravest importance,
and pastures in which the disease has broken out should
be avoided if possible (see also Appendix II,).

Curative Treatment.—The first proceeding is to shear
all affected sheep, whatever the season, for under cover
of the fleece it is practically impossible to destroy the
Psoroptes. The second is to supply the animals with
large quantities of nutritious food, as an improvement
in condition materially aids cure.

Curative treatment is divided into two methods:

1. “ Salving’’ and “‘ bottling.”
2. Dipping.

“ Salving ”’ consists in parting the fleece, and follow-
ing this by inunction of the skin with mercurial ointment.

“ Bottling ’’ is similar, but the medicaments employed
are usually in the form of liniments, such as creolin,
carbolic acid, tar, etc., in oil.

Dipping is by far the best treatment. This must be
performed twice, the second dipping being carried out
after the seventh and before the fourteenth day, this
having been found to be the period after destruction of
the adult mites in which the eggs that have escaped
destruction by the first dipping will have hatched out.

This proceeding should be carried out three or four
days after shearing.

Various dips, many of which are proprietary, are in
use, but the following are the most efficient :

I.
BR Arsenic .. = et .. 1b.
Zinc. sulph. rae ae -» 5 1b.
‘Aloes Be she ts sin Ube
Aqua nF 4 ae -. 100 lb.=124 gals,

The aloes must be first dissolved in a sufficient quantity of
boiling water, and added to the remainder.

32 VETERINARY PARASITOLOGY

II.
B Arsenic
Pot. carb. =e
Sulphur aa 2 1b.
Soft soap
Water .. Ae oe .. 100 gals.

Due precautions must be taken against poisoning by
providing a draining-pen, and by placing dipped sheep
in a yard free of herbage. Lambs must be kept apart
from the ewes, or they may become poisoned by sucking.

The arms of the men employed in dipping must be
free from wounds.

The following dips are recommended by the Board
of Agriculture :

III.

B Sulphur i is 34 -» 25 1b.
Quicklime si ae se -. 12$ Ib.
Triturate until free from lumps, and boil with 20 gallons of
water until dark red in colour, adding water up to 20 gallons
to allow for loss by steam. When cool, decant and make
up to 100 gallons.

IV.
BR Carbolic acid (97 per cent.) .. -» 3 quarts
Soft soap is : eg -» § Ib.
Water .. oi a ae .. ad 100 gals.

Dissolve the soap in the carbolic acid and add the water.

V.
B Offal tobacco ies eet -» 35 1b.
Water .. : +. 21 gals.

Steep for four days; strain and press residue to obtain all
the extract ; mix together ; add flowers of sulphur, 10 lb.;
stir, and add water to 100 gallons,

Symbiotic Mange in Sheep.— The Symbiotes ovis is
a small parasite. It affects the limbs, especially the
pasterns, and slowly extends upwards, and may reach
above the knee and hock. Occasionally the armpits and
groin are affected, with subsequent swelling of the limbs.

PARASITES AFFECTING THE SKIN 33

Treatment consists in passing the animals through a
trough containing copper sulphate solution, and in-
unction of parts above the knee and hock with creolin
ointment.

This form of mange is very amenable to treatment.

NON-PSORIC ACARIASIS.

The non-psoric Acari comprise the Ixodide, or ticks,
and the Trombidiide, or running mites. The Ixodide
are by far the larger and more important group. They
are large insects, macroscopic, and live in coarse grass
and undergrowth. Dirty farms, with rough herbage,
moorland, and untrimmed hedges, provide their ideal
habitat.

Ticks have flat bodies, protected by horny shields
on both their dorsal and ventral surfaces. They are
blood-suckers, and pass the parasitic portion of their
existence on the bodies, chiefly on the limbs, of animals,
on which they gorge themselves with blood until spherical
in shape.

The rostrum is composed of two barbed harpoons
above and below a dart. In the middle is a sucking
mouth. The anus is near the mouth, and when oviposit-
ing, the eggs form clusters round the anterior extremity
of the parasite. The feet terminate in hooks, for cling-
ing. The larve possess great vitality, and can live
many weeks without food. The adult females are very
prolific, and may produce three broods in one year.

There are two divisions of the Ixodide—viz., Rhipi-
cephalus and Ixodes. In Rhipicephalus, or, as it is
sometimes called, Boophilus, the rostrum is broad and
the body rounded ; the legs are all inserted within a
short distance from the head, and the tick possesses
a pair of eyes.

In Ixodes the rostrum is long and fine and eyes are

3

34 VETERINARY PARASITOLOGY

absent. The body may be oval or conical, and there
is a marked space between the limbs, the hindmost pair
of which often take origin even from the lower half of
the body.

Life-History.—Ticks pass through the usual four stages
in the course of their existence—viz., egg, hexapod,
larva, nymph or pupa, and finally the adult sexual stage.

The eggs are laid on the rough pasture which the
ticks inhabit, usually at the roots of the tufts of long
coarse grass and bracken. As each of these hatches

Fic. 6.—Hexapop Larva oF RHIPICEPHALUS ANNULATUS (Enlarged).*

there emerges a white six - legged or hexapod larva,
at first destitute of any hard covering. This larva
proceeds to climb a convenient blade of grass, to which
it attaches itself by its two posterior pairs of legs. When
an animal passes, the larva fastens on to the leg with
its anterior limbs, and crawls up out of reach of the
bushes and foliage, which might otherwise brush it off.
It then buries its rostrum in the skin, and sucks blood

* After Stiles (?) compare ‘‘Moussu and Dollar’s Disease of
Cattle, Sheep, Goats, and Swine,” p. 418.

PARASITES AFFECTING THE SKIN 35

for about two days, when it loses its clinging power and
drops off. Some of the ticks complete their life-cycle
on one animal, and in these the piroplasm is transmitted
through the egg. It now proceeds to moult, and becomes
the nymph, with eight legs, but differing from the
adult in being destitute of sexual organs. It again
seeks the summit of a blade of grass, and becomes
attached to another animal host, on which it remains for
about four days. It again gorges, and becomes black
with blood, when it falls off, to again moult, and finally

Fic, 7.—IxoDES REDUVIUS.*
Enlarged.

develop into the sexually adult tick. The females are now
fertilized by the males, gorge, fall off, and lay their eggs.

When full of blood, the ticks are dark in colour and
opaque, and easily removed from their host. In the
grass the tick abstains from food, and often fasts for
a considerable period. In the asexual stages the tick
shows no desire for any particular animal, but in the
adult stage each variety of tick attaches itself to an
animal of one definite species. In those ticks which
require more than one host it is in the nymph stage

* See p. 432 ‘‘Moussu and Dollar.”

36 VETERINARY PARASITOLOGY

that the parasite first becomes a carrier of the various
piroplasms, which cause those diseases grouped under
the heading of ‘“‘ piroplasmoses,” and it is as an
adult that it transmits the piroplasms to another
animal.

Except in the role of a transmitter of disease, none of
the ticks harm their host to any extent. At the most,
and only then when in considerable numbers, they give
rise to itching, and possibly anemia. We append a list of
a few of the diseases due to piroplasms, together with
the ticks which transmit each :

British Redwater.. .. Ixodes reduvius | Probably
Ixodes ricinus identical.
Hemaphysalis punctata.
(In the pig) Ixodes plumbus.
Texas Fever .. Rhipicephalus annulatus or bovis.
South African Redwater Rhipicephalus Australis, var. de-
coloratus (blue tick).

Rhodesian Redwatey .. Rhipicephalus appendiculatus
(brown tick).
“ Carceag’’ of Sheep .. MRhipicephalus bursa.

Malignant Jaundice, ov Hemaphysalis Lechi.
Canine Pivoplasmosis
South African Heartwater (In sheep) Amblyomma Hebreum.

It is difficult to eradicate ticks from a farm, but the
following methods are adopted :

1. Ploughing all rough pasture, trimming hedge-
bottoms, and dressing the land with salt or lime.

2. Removal of ticks from infested animals by hand
and by dipping.

3. Pasturing animals of a different species on the
land, in order that the piroplasms may gradually die
out. The ticks, however, are not easily destroyed by
this means.

The other non-psoric Acari are of little importance.
The autumn grass mite Leptus autumnalis) is the
hexapod larva of the harvest mite (Trombidium holo-

PARASITES AFFECTING THE SKIN 37

sericeum). It occasionally attacks horses and dogs,
producing a pustular eruption and a considerable
amount of itching. The pustules are at first small, but
may reach the diameter of a shilling, and are seen on the
back, on the muzzle, and between the thighs. The con-
dition is quite amenable to treatment with parasiticides.

PHTHIRIASIS (LOUSINESS).

The lice include all the Aptera, with the exception
of the fleas. The Pediculine are divided into Pedicu-
lide and Ricinide. The two chief types of louse are
Haematopinus and Trichodectes, the former being a
division of the Pediculide, and the latter of the
Ricinide.

The true lice (Hematopinus) have a projecting
rostrum, with barbed hooks, and in addition a hollow
extensile sucker. The legs are provided with hooked
terminal joints. They have simple eyes, are wingless,
and pass through none of the ordinary intermediate
stages between the egg and the perfect parasite, as in
the Acari. The eggs are oval in shape, are attached
to the hairs, and are commonly known as “nits.” In
Heematopinus the shape of the body is generally said
to resemble that of a Dutch doll—that is to say, the
thorax is larger than the head, and the abdomen larger
than the thorax. With the exception of the sheep, all
animals may be affected with one or more varieties of
Hematopinus.

The Hzmatopinus forms are blood-suckers.

Trichodectes.—These are epidermis-eaters, and the
head is modified for this purpose. Instead of being
terminal, as in Hematopinus, the mouth is situated
on the under surface of the head, which is broad and
shield-shaped. In these the thorax is the smallest
segment of the body.

38 VETERINARY PARASITOLOGY

The various lice found on each animal are enumerated
below :
Hematopinus macrocephalus.
Horse { Trichodectes pilosus.
Trichodectes pubescens.
Hematopinus eurysternus.

[ Hamatopinus vituli.
Hematopinus tenuirostris.
Trichodectes scalaris.

Sheep { Hematopinus pedalis.

Trichodectes sphzrocephalus.

Ox

Pig .. Hematopinus urius.

f{ Hematopinus piliferus.
Dog *\ Trichodectes latus.
Cat .. Trichodectes subrostratus.

Symptoms.—These vary a good deal, in accordance
with the variety of louse present. The Hematopinus
forms suck blood, and
hence cause more
irritation than those
which live on desqua-
mated epidermis and
secretions. The
usual signs are emacia-
tion, irritation, and
"4 rubbing, scurfiness

eng of the skin, with the
a S hair erected, and
oa AN sometimes crusts or
(Meare K blood from rubbing.
ALLE Usually the lice them-

— rl Mh

WED

~

Tae selves or their ‘‘ nits ”’
can be found. They
are more active in
summer than in
winter, and may
Fic. 8.—TRICHODECTES SCALARIS. remain on one animal
Greatly enlarged. a very long time.

PARASITES AFFECTING THE SKIN 39

In the Horse.—They may be found under the mane,
at the root of the tail, and on the shoulders and quarters
in advanced cases, and seldom or never under the belly.

In Cattle—Tvichodectes scalaris is much the com-
monest. It has no predilection seat, and may be
found all over the
body.

Hematopinus
forms are located
along the neck and
spine. In sheep,
Trichodectes are

commonest round ee
the point of the SA e
shoulder, and leave (2A } ax
bare patches, TEA 4
In Pigs.—Hemato- ww

pinus urius is the e¥
largest of all lice.

It attacks the neck, lh
head, and armpits,
and frequently causes

——
=
=
——

—-

death in young pigs. \ Kl

Treatment. — Care iy Gila lf |
must be taken to : AHMAR Wid
prevent the spread- l |
ing of the parasites , \
to other animals by Wp if

grooming utensils or Fic. 9.—H#matopinus Macro-
any other means. ee eae eee
To destroy lice, :
creolin baths are best, repeated in a week.
Jeyes’ fluid (zr in 60) is very efficacious, especially
if some soft soap is previously dissolved in the water.
Other agents which may be employed are : Decoction
of stavesacre (rin 20) ; mercurial ointment rubbed down

40 VETERINARY PARASITOLOGY

the back in cattle; and various so-called insect powders,
such as pyrethrum, stavesacre seeds, etc.

Decoction of tobacco (1 in 20) is often used.

Sheep may be dipped.

The same precautions as regards disinfection should
be taken as in mange.

A mite which sometimes causes symptoms allied to
those of Phthiriasis is the Dermanyssus gallina, or fowl
mite. This often attacks horses kept in a stable in
which fowls are in the habit of roosting. Dermanyssus
avium may cause similar symptoms, and their presence
is said to result from swallows or sparrows nesting in
the roof of the stable. The mites attack chiefly the
neck, withers, and back, causing loss of hair and a
scurfy appearance of the skin, accompanied by intense
pruritus and constant rubbing.

The mites can usually be found:on the skin.

Treatment is similar to that for phthiriasis.

Pulicide (Fleas).

On dogs Pulex serraticeps is common. It is large, and
brown in colour, while Pulex iyritans of man is smaller
and darker.

The complex life-cycle may take place on one host.
This is often observed in the cat, especially in long-
haired varieties, on the skin of which often a consider-
able number of comparatively large white eggs may be
found.

Symptoms.—There is constant irritation and scratch-
ing, and occasionally an eruption may be seen on the
back. Fox-terriers seem particularly liable to this
eruption, and in these it takes the form of dark-coloured
circumscribed hairy patches, with irregular surfaces.
They are frequently confounded with mange, ringworm,
and other skin affections.

Treatment.—Creolin baths are most useful. In the

PARASITES AFFECTING THE SKIN 41

smaller varieties of dogs and in cats ol. anisi or ol.
eucalypti in spirit are best, though these do not neces-
sarily destroy the parasites.

All mats and bedding should be destroyed, and
kennels disinfected and limewashed.

Cutaneous Filariasis.

In Russia, Hungary, and some few other countries,
horses, more particularly thoroughbreds, often exhibit
symptoms of what is known as “ parasitic skin-bleed-
ing.”

The cause is a worm, either Fularia multipapillosa or
Filaria hemorrhagica. °

Filaria multipapillosa is from 2} to 23 inches in length.
Its cephalic end shows a series of papille, arranged in
rows, from which it derives its name. The body is
transversely striated. Within the nodules the worm is
coiled into a spiral. It is ovo-viviparous, and is prob-
ably carried to various parts of the body at some stage
by the blood-stream.

Symptoms.—These are more apparent in warm
weather, and may recur during several successive
summers.

Non-inflammatory nodules about the size of a pea occur
on the neck, shoulders, and breast. From these there
exude drops of blood at intervals. The hair becomes
matted, and after a while streaks of blood are seen on
the skin. The general health is unimpaired. They
often cause inconvenience owing to their position under
the harness.

Treatment.—Clip the part, and apply alcohol or tinct.
iodi. Any parasiticide may be employed. Arsenic
should be administered internally.

In Hungary the swelling is incised, and the worm
extracted just at the time when it is about to open.

42 VETERINARY PARASITOLOGY

Filaria Irritans.

This parasite in the larval state causes a disease of
the skin known as “ parasitic granular dermatitis,” or
“summer sores.” The parasite is found in South
Europe, Algeria, and India. It becomes surrounded by
a calcareous capsule, and remains in the skin all
the summer. Probably it gains entrance from the
surface.

The nodules are commonest on the parts normally
covered with harness, and probably friction plays a
part in introducing the parasite.

Treatment.—Sulphide of arsenic has been successfully
used.

Phenol or iodoform collodium are of service.

Dracontiasis.

In India, Africa, Egypt, Persia, and South America,
the guinea-worm (Fularia Medinensis) sometimes lives
in the skin of the horse, dog, or cow.

It is a large worm, and buries itself in the connective
tissue. In time one end emerges through an orifice in
the skin, and the Indians then remove it. It is stated
that if the worm is broken in the process, death of the
patient at once follows, but this is open to grave
doubt.

Embryos are set free by the rupture of the body of
the worm, and pass this stage of their existence inside
small crustaceans. After some while they are taken
into the body of one of the larger animals during the
act of drinking, and reach the stomach, where fertiliza-
tion takes place. The males then die, and the females
bore to the surface.

Fleming has recorded chronic lameness in horses
caused by this parasite.

PARASITES AFFECTING THE SKIN 43

DIPTERA AFFECTING THE SKIN.

Besides the Aphaniptera, or fleas, already described,
members of the Nemocera and Brachycera may attack
animals in the réle of transitory parasites.

The Nemocera possess long, extremely fine antenne,
made up of six distinct segments, and are thus distin-
guished from the flies. The larve have distinct heads.
They include the Culicide, or mosquitoes, and the
Simuliide, or sand-flies.

The Brachycera are divided into the Tabanidz (breeze-
flies) and Hippoboscide, or Pupipara.

I. Culicide (the Mosquitoes).

These are of more importance in human than in
veterinary medicine, as they are the carriers of the
organism which causes malarial fever of man. The
females are the more important, as the males are not
blood-suckers, but live on the juices derived by suction
from flowers and plants. Several generations are pro-
duced in one season. The females are fertilized by the
males late in autumn, and then proceed to hibernate.
In the early spring they search for a marshy spot, and
lay their first batch of eggs in close vicinity to water.
The larve are aquatic, and in about a fortnight they
become pupe. A few days later the perfect insect
emerges.

The gnats are a well-known species, extremely com-
mon in the neighbourhood of trees and bushes, among
the foliage of which they rest after feeding. The
buzzing sound caused by the rapid movement of their
wings is only too well known.

2. Simuliide (the Sand-Flies).

These are often spoken of as buffalo-gnats. They are
small and thick-set, and have not the characteristic

44 VETERINARY PARASITOLOGY

buzz of the mosquito when flying. They are gregarious,
and move in flocks, settling occasionally, but never
appearing to rest for any length of time. The larve
are aquatic. Only the females are blood-suckers. They
attack only unprotected portions of the body, as the
mucous membranes, especially the conjunctiva and the
skin over the inside of the thighs and ears. They punc-
ture the skin, producing raised swellings and intense
irritation, followed by desquamation of the epidermis.
Occasionally, when a large number attack the skin,
serious symptoms may result. The chief are dyspneea,
associated with fever, which may be followed by death.

The Brachycera

are flies with short antenne. Usually they are winged,
and have the posterior pair rudimentary. Larve
apodal, with no distinct head. The chief families are:

Tabanidz (breeze-flies).
Muscidz (house-flies).
(Estridz (bot-flies).
Hippoboscide, or Pupipara.

RODH

I. Tabanide (Breeze-Flies).

These have a broad, flattened body, and the head
broad and flattened from before to behind. The pro-
boscis is capable of piercing the thickest hide. These
flies are distributed all over the world, and are to be
seen in the heat of the day, usually in the neighbour-
hood of woods, where, by the buzzing sound they make
during flight, they strike terror into cattle and horses in
the neighbourhood.

The breeze-flies are responsible for the spread of surra,
and it is not unlikely that they might convey the bacilli
of anthrax.

PARASITES AFFECTING THE SKIN 45

There are hundreds of species, of which may be men-
tioned :

The Autumnal Breeze-Fly.—18 to 20 millimetres long.
Thorax grey, with four brown longitudinal bands ;
abdomen with three rows of white spots ; legs yellowish-
white.

The Ox Breeze-Fly.—A very large fly, 27 millimetres
long. Thorax covered with yellow hairs, with black
longitudinal bands; abdomen brownish, striped with
fawn. Each ring bears on the middle of its dorsal
surface a white spot.

Allied are the Hematopota, of which may be men-
tioned the small rain breeze-fly (H@matopota pluvialis).

2. Muscide (House-Flies.)

These have a large number of genera and species.

Two groups are parasitic during the larval stage:
(x) Sarcophaga ; (2) Lucilia.

The following are parasitic (blood-suckers) during
adult life :

I) Stomoxys.
2) Glossina (tsé-tsé).
) Hamatobia.

(4) Muscidz.

(5) Cstride.

(6) Hippoboscide.

Stomoxys Calcitrans much resembles an ordinary house-
fly, but its head bears an elongated proboscis, extending
far in front.

It attaches itself usually to the legs or neck of a horse,
and can only with difficulty be knocked off. It causes
great irritation, and in fine-skinned horses the attack
gives rise to a papule.

Glossina Morsitans (Tsé-tsé Fly)—Similar in appear-
ance to a house-fly. Proboscis very long and slender ;

46 VETERINARY PARASITOLOGY

thorax chestnut, with four black longitudinal stripes ;
abdomen yellowish-white, composed of five segments
(the last four each carry a large black spot) ; wings more
opaque and more leaden in colour than those of the
house-fly. It is this fly that conveys the dreaded
nagana of Africa.

3. The stride.

These are exclusively parasitic. They have large
wings, and the body is usually covered with downy hair.
The abdomen is composed of six rings, and terminates
in an extensile ovipositor. By means of this the female
deposits eggs on some portion of the body. The larval
stage is parasitic.

Hypoderma Bovis.—Length, 13 to 15 millimetres.
Head grey ; thorax grey on anterior half, black on pos-
terior half, and bears wide longitudinal black bands ;
abdomen black, shows three bands of coloured downy
hair, anterior yellow, middle black, posterior orange ;
wings brownish.

The fly is active from the beginning of July to the
beginning of September. It lays its eggs along the back,
shoulders, and occasionally on the fore-limbs. The flight
of this insect is accompanied by a loud buzzing noise,
which terrifies cattle, although no pain is caused by the
fly, as the ovipositor is soft, and does not penetrate the
skin. The female deposits only one egg at a time, and
then leaves the host, makes a short flight, and returns
to repeat the process ten or twelve times. The eggs are
white and elongated, and carry a brown terminal
appendage, which fastens them to the hairs.

The larvee are known as “ warbles,” and live in the
subcutaneous tissue. Probably the eggs or young larvee
are licked off, and after passing into the alimentary
tract, finally reach this position. Nothing is noticeable
during the winter, but in the following spring small non-

PARASITES AFFECTING THE SKIN 47

painful elevations about the size of a hazel-nut appear
on the skin of the back and arms. In each of these is
a “warble.” At the summit of each elevation is a
small hole, and the larva applies its posterior extremity
with its ‘ breathing-holes”’ to this. In June the larva
emerges through this apical orifice, after it has become
enlarged. The ‘“‘ warble’? now becomes buried under
leaves or straw, and after passing through the chrysalis
stage, finally develops into a fly.

The larva is brownish in colour, and composed of
eleven rings. In shape it is conical, and much resembles
a “bot.” The head bears two hooks for anchoring,
arranged at right angles. The spines are arranged in
three rows on each side, leaving out the centre portion,
except in the last two segments, which are unarmed.
The lateral prominences consist of an upper and lower
in each segment, and are well marked.

When mature, the larva measures 22 millimetres to
28 millimetres in length, and about 15 millimetres in
breadth at the widest part.

Treatment is usually unnecessary. If desired, the
elevations may be coated with salicylic acid, or iodoform
collodion, or even Stockholm tar. These suffocate the
parasite by closing the air-holes.

When the larva is ripe, it may often be squeezed out,
especially if the skin over the elevation is first slightly
nicked with a bistoury.

Prevention is of more importance. The backs of
cattle should be dressed during the months the fly is
active with a mixture of sulphur, ol. picis, train-oil, and
rape-oil, at least once weekly, to ward off the attacks
of flies.

Hypoderma Equi (Loiset).—This parasite is found in
Holland, Belgium, and France. It produces cutaneous
tumours containing a larva, and in all its characteristics
much resembles Hypoderma bovis.

48 VETERINARY PARASITOLOGY

The larva is only 9 to 10 millimetres in length. It
has no spines and no oval hooks, and the skin is very
thin and transparent.

The tumours usually arise under parts which are
commonly covered by harness,
_, such as the neck, withers, and
7 back.

Curative treatment may be
applied, as in the ox.

Gstrus Ovis is a small
greyish-coloured fly, 10 to 12
millimetres in length. Thorax
brownish-grey, streaked with
dark obscure lines; abdomen
slightly hairy, marbled with
yellow, black, and white. The
wings carry at their bases three
black spots.

The fly is active from May to October.

The larve enter the nasal cavities of sheep, and finally
reach the sinuses and horn-cores. They will be discussed
more fully later.

Fic. to.— Cistrus Equi.

4. Hippoboscide, or Pupipara.

The female deposits the nymph.

There are two species of importance :

I. Hippobosca Equina (the Spider-Fly).—This fly
attacks the soft parts of the skin of the horse, or even
ox or dog, especially around the anus, eyes, and groin.
It does not puncture the skin, but merely irritates. It
is only 8 millimetres in length.

It is a very obstinate insect, and can only with
difficulty be driven away. It causes great stamp-
ing and kicking among animals with fine sensitive
skins.

Hippobosca rubipes is a native of South Africa, and is

PARASITES AFFECTING THE SKIN 49

believed to transmit the Trypanosoma Theileri, which
causes the so-called biliary fever of cattle.

(2) Melophagus Ovinus (Sheep-Ked).—This insect is
without wings, and much resembles a louse. It lives
in the wool of sheep, and finds its nourishment in the
grease, scurf, and droplets of exuded blood.

It is greyish-brown in colour, with a small narrow
thorax and a large oval abdomen. Length, 3 to 5 milli-
“metres.

Muscide.—Some of the Muscide exist on the skin
while in the larval state.

Sarcophaga Magnifica is a greyish fly, 10 to 30 milli-
metres in length.. It is viviparous, and deposits its
larve on wounds or moist surfaces. Cattle are most
commonly attacked.

In the British Isles Lucilia Cesar and Lucilia sericata
are the commonest.

Lucilia macellaria is common in America.

Lucilia sericata is of a greenish-blue colour, and smaller
than Lucilia Cesar, which has a golden sheen.

The former has the first ring of the abdomen black,
and the latter the first two rings. These flies deposit
their eggs on the fleece of sheep, particularly round the
anus or where there is a wounded surface.

The eggs hatch the same day.

Cupri sulph. is the best agent in use for the purpose
of destroying the larve.

CHAPTER II
PARASITES OF THE ALIMENTARY TRACT

VERMES

THE Vermes are non-vertebrate animals, possessing soft
contractile bodies, devoid of an endo-skeleton, but con-
stituted of a number of segments. They possess no
articulated limbs. The organs comprising the secretory
system are arranged in pairs. With the exception of
the leeches, all the members of the Vermes under this
heading which we are about to discuss are classed as
Entozoa, or intestinal worms. Their natural habitat is
to be found in some portion of the alimentary tract of
a larger animal, apart from which but few can maintain
their existence. They have no respiratory system, and
hence need no circulatory system.
The Vermes are divided into two chief groups :

1. Annelida.
2. Helminthes.

1. ANNELIDA.

The only members of the Annelida which are parasitic
are the leeches, of which Hemopfis sanguisuga, the horse-
leech, serves as an example. The Annelides are the
only invertebrates which have red blood circulating in
a double system of bloodvessels. The body is soft, fiat
or cylindrical, and shows distinct transverse rings.

Hemopis sanguisuga is a member of the Hirudine.

50

PARASITES OF THE ALIMENTARY TRACT 51

It has an elongated body, flat on the ventral surface:
and rounded on the dorsal surface. The mouth carries
a tri-radiate, three-lipped sucker, used both for the
purposes of assimilation and locomotion, and there is
an anal sucker in the form of a flattened disc. The
oval sucker is soft, and so the horse-leech is unable to
attach itself, except to an abraded surface or a mucous
membrane.

The Hirudo medicinalis, on the other hand, has hard
jaws, and is able to puncture sound skin. Although the
leeches are hermaphrodite, a pair are necessary for fer-
tilization, the penis being situated at the anterior end
of the body, and the vulva a short distance behind it.

The horse-leech frequents muddy pools, and the
young parasites enter the pharynx of horses, asses,
mules, or even man. During the process of drinking
they become attached to the mucous membranes, from
which they suck blood.

Symptoms.—When the leeches are present in great
numbers anemia and debility arise from loss of blood.
The patient frequently coughs, and such attempts to
remove the parasites are followed by discharge of blood,
which has accumulated in the pharynx, down the nose.
This is particularly seen when the animal is at work.
Sometimes hundreds of leeches may be present at one
time, and cause dyspnoea through obstruction of the
pharynx.

Treatment.—Prophylactic treatment consists in pre-
venting the animals from drinking water from streams
or pools infested with leeches. When this is im-
possible, the water should be filtered through finely
perforated metal trays, or net muzzles may be used
while drinking.

Curative treatment is usually successful. Strong salt
solution on a sponge should be applied to the pharynx,
as this dislodges the parasites.

52 VETERINARY PARASITOLOGY

2. HELMINTHES.
These are divided into :

1. Platyhelminthes, or Platodes (flat-worms).
2. Nemathelminthes, or Nematodes (round-wormis).

The former are practically all hermaphrodite.
They are again divided into two classes :

(x) Cestodes.
(2) Trematodes.

(1) The Cestodes contain the tapeworms. They have
long, flattened, ribbon-like bodies, distinctly segmented,
and a head provided in most cases with hooks and suckers.

The Tenioide are the most highly developed.

The Bothriocephalide are allied.

In the Tznioide in general the head bears from two
to four suckers. Between these, and centrally placed,
there may be a rostellum, armed with one or more circles
of hooks or spines, or in some cases there is merely a
depression provided with a pore.

The body tapers anteriorly, and the segments gradu-
ally become ripe from behind forwards; hence the ter-
minal segments are usually crammed with eggs. The
segments multiply by a process of division from behind
the head at the same rate as the terminal segments are
shed or have withered, as the case may be. Each seg-
ment is hermaphrodite, and provided with one or two
genital pores opening out from a uterus, usually con-
sisting of a median trunk and numerous lateral branches.

The position of the genital pores varies. Thus, in
Tenia cucumerina there is one on either side of each
segment, while in Tenia marginata they are arranged on
opposite sides, one in each segment. In Tenia litterata,
again, the genital pores are centrally placed.

In all the Tenioide the embryo escapes from the
ovum and enters the alimentary tract armed with six

PARASITES OF THE ALIMENTARY TRACT 53

hooks, and is known as the “‘ proscolex.’”’ It leaves the
intestine, penetrates into the tissues of the host, loses its
hooks, and becomes a vesicle, from the inner surface of
which develops the head of the future tapeworm. This
head has received the name “ scolex.’’

When the carcass or portion of the carcass of an
animal thus infested is eaten by another animal, the
scolex is liberated, attaches itself to the mucous mem-
brane of the intestine, and develops a number of seg-
ments, or proglottides. The terminal segments pass out,
and are ingested by yet another animal, and so the
cycle commences afresh.

(2) The Trematodes have a flattened, oval, or lanceo-
late body, which is non-segmented. Those which are
parasitic belong to the Distomata—that is to say, they
have an anterior oval sucker and a round or oval ventral
sucker, varying in position in the different members.
They are hermaphrodite, but individual coitus is
essential.

The genus Bilharzia (Bilharzia crassa) inhabit the blood.
They are not hermaphrodite, and the male and female
are always attached, the male lying in a groove running
the length of the female.

The Distomata comprise :

(a) Distomum.

(0) Amphistomum.
(c) Gastrodiscus.
(d) Bilharzia.

The flukes are of great importance, as they inhabit the
bile-ducts, and cause the disease known as “ liver-rot.”

Nemathelminthes.

These are round-worms, as opposed to the Platyhel-
minthes, or flat-worms. The sexes are nearly always
distinct,

54 VETERINARY PARASITOLOGY

They are divided into two chief orders :

1. Nematoidea (the Nematode worms).
2. Acanthocephala (the thorn-headed worms).

1. THE NEMATODES

have a transversely striated skin. They possess a
digestive canal running the whole length of the body,
but no circulatory apparatus.

They may be found in any tissue of the body, except
the osseous skeleton. Their colour may be white, red, or
brownish. The head may be armed, but definite hooks,
such as are seen in the Teeniz, are absent. In many
the anterior end of the body carries just behind the head
a pair of small membranous wings. Often there is a
caudal pouch into which the genital duct and intestinal
canal open by means ofacloaca. In the males chitinous
spicules are often present, and are used in the process of
copulation as “‘ claspers.”’ The Nematodes are oviparous
or viviparous, and the females have a vulva on the floor
of the body. Into this the uterus opens. This organ
is provided with one or two ovarian tubes. In the
majority the life-history has not been thoroughly worked
out, but it is evident that some members complete their
life-cycle in one host, while others require an inter-
mediate host. The females are by far the commoner,
and are larger. The males often exhibit spiral coiling
of the posterior extremity.

The Nematoidea are divided into :

(x) Ascaridze.

(2) Oxyuride.

(3) Filariide.

(4) Trichotrachelide.
(5) Strongylide.

(1) Ascaride.—The body tapers towards each ex-
tremity. The mouth has three lips, and between these

PARASITES OF THE ALIMENTARY TRACT 55

is a short tube, which can be slightly protruded. The
male has no caudal pouch, but has two spicules, or
“claspers.” The females have a straight digestive
canal, and two tubular, spirally-arranged ovaries, several
times longer than the body. They open at the vulva,
which is situated at about one-fourth of the length from
the anterior extremity.

The Ascarides inhabit the small intestine, and may
enter the stomach. The lumbricoid worms are found
in the large intestine.

(2) Oxyuride.—These worms inhabit the large intes-
tine. They are oviparous. The mouth is provided
with three lips, and the tail is tapered and much finer
than the remainder of the body. The caudal pouch is
absent in the male.

(3) Filariide.—The body is long, slender, and thread-
like, and the rings are less pronounced. The mouth is
a circular opening. In females, the vulva is situated
at the anterior end of the body. The males usually
have the tail rolled up. They are not found in open
cavities, but inhabit the parenchymatous tissues, being
frequently embedded in the subcutaneous tissues (see
Cutaneous Filariasis, p. 34), tendons, or within the an-
terior chamber of the eye. These represent the Filaria
type; but the Spiroptera embed themselves chiefly
between the layers of the viscera, such as the cesophagus
and stomach, in the form of nodules, under the mucous
membrane.

(4) Trichotrachelidze.—These are so called on account
of the beaded or constricted cesophagus. The body
is extremely slender, and tapers at the anterior
extremity.

There are two genera :

(a) Tricocephalus, usually inhabiting the intestine.

(0) Trichina, usually found encysted in muscular
tissue.

56 VETERINARY PARASITOLOGY

(5) Strongylide.—In these the body is rounded, and
but seldom thread-like. The mouth bears six oval
papille. The males have the vent enclosed in a divided
or entire caudal pouch, from which the organ of genera-
tion can be protruded. There are usually one or two
“claspers.”’

The three chief groups of the Strongyles are :

(a2) The Eustrongylines.
(2) The Strongylines.
(c) The Sclerostomines.

The chief differences are set out in the following
table :

Mouth. Caudal Pouch.
Eustrongylines .. Non-chitinous Not ribbed
Strongylines a Non-chitinous Ribbed
Sclerostomines .. Chitinous Ribbed

2. THE ACANTHOCEPHALA.

These worms are provided with a sort of proboscis, set
with recurved spines, by means of which they attach
themselves to the intestinal mucous membrane.

Echinorhyncus gigas of the pig is the largest known
member.

Digestive organs are absent, with the exception of
two small blind tubes arising at the base of the pro-
boscis.

The males probably fertilize the ova after they have
been excluded.

PARASITES OF THE ALIMENTARY TRACT 57

PARASITES INHABITING THE ALIMENTARY CANAL
OF THE HORSE.

Csophagus and Stomach.

Strongylus Axei.—This is a small filiform worm,
usually about 6 or 7 millimetres in length. It coils
itself up under the mucous membrane in the form of a
small nodule. It causes no symptoms, and is of little
clinical importance.

Filariide.—Two Spiroptera may inhabit the stomach
of the horse. These are Spivoptera megastoma and
Spiroptera microstoma—i.e., the large-mouthed and
small-mouthed Spiroptera. Their average length is
I centimetre (2? inch). They may be
found free in the cavity of the stomach,
but more frequently embedded in raised
nodules in the mucous membrane, chiefly
in the cardiac portion, and ranging in
size from a pea to a walnut, with a
small aperture at the summit. As the
nodules grow older they become sur-
rounded by connective tissue, and finally
by acalcareous capsule. They appear to
be more common in the ass than in the

horse. Aa - abet Fic, 11.—Larva
They may produce chronic indiges- oF Gastro.
tion, or even gastritis, with ulceration PHILUS EQui.
: The horse
and slight hemorrhage. dibest

Gastrophilus Equi Larve.—The com-
mon horse “ bot’’ is the larva of the fly known as the
Gastrophilus, or Estrus equi. The latter is a compara-
tively large fly, with the proboscis directed forwards.
The colour is a mixture of orange, yellow, and brown.
The wings each show a light brown bar and two ter-
minal spots of the same colour. It is a common
parasite in the stomach of the horse, especially in those

58 VETERINARY PARASITOLOGY

horses which have been at grass during the months in
which the fly is active.

The eggs are laid by the adult female, and glued to
the hairs of the fore-limbs of the horse, or in some
position from which they may be easily reached by the
mouth. The eggs are provided with “‘ opercula,”’ or
lids, which open and liberate small maggot-like larve.
These cause irritation, and are licked off by the horse,
and on reaching the stomach attach themselves by
means of their hooked mandibles to the mucous mem-
brane of the cardiac end of the stomach. They then
undergo two moultings, and finally develop into the
so-called ‘ bots.”

Each bot is pyriform in shape, tapering towards the
head, and is composed of eleven segments, the first eight
of which carry a double row of stiff spines directed back-
wards. The anterior tapered end carries two smooth
antennz, while the posterior end has two pores or aper-
tures for breathing. This bot is a dirty white in colour.

Bots may migrate, and so reach the brain, larynx,
pharynx, or bladder. The larve remain in the horse’s
body for about nine months, and pass out with the
feeces in the spring. After excretion, they shrivel and
take on the chrysalis stage. They then undergo three
moults, and finally emerge as adult perfect insects.

Another variety of bot which is fairly common in this
country is the Gastvophilus hemorrhoidalis. In this
case the fly lays a number of brownish eggs around the
muzzle and lips of the horse. These bots are of a dirty
green colour, and may be frequently seen after the horse
has passed feces, attached to the inner rim of the anus.

Its habitat is identical with that of Gastrophilus equt,
but it remains in the rectum for a little while instead of
passing out at once.

In Russia Gastvophilus pecorum is the common bot,
and is occasionally seen in Russian ponies brought over

PARASITES OF THE ALIMENTARY TRACT 59

into England. It is of a dark red blood tint. The
colour is densest at the head, while at the tail end it is
much lighter.

In Australia Gastrophilus nasalis is common, and it
is occasionally seen in England. The bot attaches itself
to the pyloric end of the stomach and to the duodenum.
It is frequently found in the pharynx and cesophagus,
causing dyspnoea and coughing.

Symptoms.—As a general rule, bots cause little or
no disturbance. Occasionally chronic indigestion may
result, and this may be associated with ulceration or
perforation of the stomach wall. Colic occasionally
results from their presence, and spasm of the cesophagus,
associated with retro-peristalsis, has been noticed when
bots have been present in sufficient number to cause
obstruction.

Treatment.—Owing to their great vitality, it is prac-
tically impossible to introduce medicinal agents into the
stomach in sufficient concentration to destroy the bots.
In the spring they leave the horse, and should then be
destroyed, in order to prevent increase in the number
of bot-flies in the succeeding year.

The following prescriptions are in common use:

BR Creolin ws or 4 .. Bij.
Ol. tereb. oe #4 os .. 5y-ss.
OL lini .. as ic AP .. ad OQj.
M. Fiat haust.
R Carbon disulphide .. : 3ss.
This is best given in a eapaile:

BR Benzene 23 ie a sa Be
Tinct. iodi. .. $8 at .. 58s.

OL lini.. Se Ais ins .. ad O,j.
M. Fiat haust.

B Creosote des es o se Bi.
Chloroformi .. Ze ree .. Bij.
Ol.{tereb. a ae ae .. 3Bj.ss.
Ol. lini .. ae a ae vs Ode

M. Fiat' haust.

60 VETERINARY PARASITOLOGY

Gastrophilus hemorrhoidalis may be removed from
the rectum by injections of salt solution.

Bots, when present in the pharynx, may be removed
by the use of the above mixture applied on a long brush
or on a sponge fastened on a stick.

Among the parasites sometimes found in the stomach
of the horse, Ascaris megalocephala must be included,
but will be discussed later.

Ganglyonema scutatum may sometimes be found in the
cesophagus.

Intestinal Parasites of the Horse.

TANIA.

The Tenia which inhabit the intestine of the horse
are only three in number, and all belong to the Anoplo-
cephaling (the unarmed tapeworms).

The three Teenia are :

1. Tena perfoliata.
2. Tema plicata.
3. Tenia mamillana.

Of these, Tenia perfoliata is by far the commonest.
It inhabits the large intestine, particularly the czecum.
Tenia mamillana is very rare, and has seldom, if ever,
been seen in horses in the British Isles. It inhabits the
small intestine, as does also Tenia plicata, which is by
no means uncommon.

Tenia Perfoliataa—This worm ranges from 25 to
4o millimetres in length (1 to 1? inches), and is about
ro millimetres (? inch) wide. The head is four-sided,
large, and rounded, while the four suckers are rounded
and placed at the extreme end of the head.

Tenia perfoliata may easily be recognized by the
presence of two flaps on each side, which project back-
wards, and are quite easily visible to the naked eye.

PARASITES OF THE ALIMENTARY TRACT 61

Tenia Plicata is by far the largest of the three. In
length it ranges from 1} to 8 centimetres. Its width
is about 15 millimetres. The head is more flattened than
that of Tenia perfoliata, and is destitute of flaps. It
carries four round terminal suckers.

Tenia Mamillana is the smaller. In length it ranges
from ro to 30 millimetres, and its width is about 5 milli-

Fig, 12.~HEAp oF TANIA Fic, 13.—TAnNiA
PERFOLIATA. PERFOLIATA.

metres. Its head is peculiar—short and broad, and
somewhat resembles a rose-bud in shape. The suckers
are merely slits, and are laterally placed.

Symptoms.—In the horse there is usually little evi-
dence to show that Tznia are present in the intestine.
Anemia and slight debility may be observed when the
number present is very large. Cases of septic peritonitis
following perforation of the intestine have been recorded,
but must necessarily be very rare.

Treatment.—When the presence of tapeworms is

62 VETERINARY PARASITOLOGY

demonstrated by their occasional appearance in the
feces, treatment is sometimes resorted to. As they are
unarmed, there is little difficulty in expelling them.
The following draught is usually efficacious :

ROL. tereb. ei £2 on oe 3ij.
Creosoti es sy ea ve JO]e ;
Ol. lini .. ei ad O.j.

M. Fiat haust.
Male-fern, areca-nut, kamala, and kousso, are other
remedies frequently employed by veterinarians.

Fic. 14. HEAD oF T&NIA Fic, 15.—HEAD oF TNIA
PLicaTa. MAMILLANA.

Ascaris Megalocephala.—This is a large round-worm,
of a whitish or yellowish colour, often present in the
intestines of the horse. The female ranges from 6 to
13 inches in length, and the males from 5 to 12 inches.
The body is stiff and cylindrical, while the head is large,
easily visible, and set upon a well-marked constriction,
or neck. It carries three lips. The male possesses two
wing-like outgrowths—one on each side of the tail.

The life-history has been the subject of much investiga-
tion.

According to Albrecht, ova which are kept in moisture

PARASITES OF THE ALIMENTARY TRACT 63

or in dung at ordinary room-tempera-
tures require twenty-four to thirty days
for the complete development of the
embryos, but if incubated at 37° C.
three to four days is sufficient. He
infers that transmission of the parasite
takes place without an intermediate
host by ingestion of ova in dung. He
fixes the age at which the Ascaris gains
sexual maturity as from ten to twelve
weeks. Foals are particularly subject
to Ascarides, but they occur in horses
of all ages. Although no worms may
have been passed in the dung, their
existence may often be demonstrated
by the presence of ova in the faces.
They are rounded, and easily visible
when a portion of the feeces containing
them is mixed with a small quantity
of water on a glass slide and exposed to
a magnification of roo diameters.

Symptoms.—Usually the symptoms
are nil, but when large numbers are
present anemia and marasmus may
result. Intestinal catarrh is often asso-
ciated with their presence, and is indi-
cated by the discharge of a small
quantity of watery fluid after defeca-
tion.

More uncommon is peritonitis, pro-
duced by perforation of the intestinal
wall. Jaundice has occasionally been
seen, owing to the passage of an Ascaris
up the bile-duct, but this is rare.

In foals particularly, large numbers of Ascarides not
infrequently form a bundle and cause obstruction.

Fic, 16.—ASCARIS
MEGALOCEPHALA,

64 VETERINARY PARASITOLOGY

Nervous symptoms are occasionally seen in the form
of epileptiform spasms, vertigo, or even tetanic spasms.

Treatment.— Antimony potassium tartrate un-
doubtedly stands foremost among the agents employed
to expel Ascarides from the horse. One drachm should
be given three or four times daily for four days, and
followed by a dose of physic.

Ol. tereb. is often efficacious, given with creosote and
a full dose of ol. lini.

Male shield-fern is a well-known remedy, and is
usually combined with ol. tereb. and ol. lini.

The following is a common prescription for the so-
called ‘‘ worm-powders ”’:

BR Ferri. sulph. .. bi ays -. 3.
Arsenic ee 8 on -- grs. ij.
Santonin se ae its +» grs. Xv.
Pulv. gentianz hs we .. §ss.
Pulv. anisi ae ar cs oe Bh
Pulv. locust .. me 3j-

M. Fiat pulv. 1. Sig.: To be given in first feed daily.

SCLEROSTOMES.

‘

These worms are commonly known as “ palisade
worms.” They have chitinous mouths, and are thereby
capable of doing great damage.

Two Sclerostomes may inhabit the intestine of the
horse, and both usually exist in the same animal. These
are:

I. Sclerostomum armatum or equinum.
2. Sclerostomum tetracanthum.

Sclerostomum Armatum.—This is a short, straight,
stiff worm, of a whitish or greyish-red colour. The
female may be known by the straight-pointed tail, and
measures about 30 millimetres in length, but this is
subject to great variation. The male possesses a caudal
pouch, and is about 20 millimetres in length. Occa-

PARASITES OF THE ALIMENTARY TRACT 65

sionally specimens are found which greatly exceed this
length.

In its adult form Sclerostomum armatum inhabits the
large intestine of the horse, particularly the cecum,
hanging on to the mucous membrane. It may even be
found in the duodenum in some cases.

Life-History.—Sclerostomum armatum appears in three
different positions :

xr. Attached to the mucous membrane, or free in the
lumen of the intestine.

2. Coiled up in nodules in the submucous tissue.
These tumours range from the size of a millet-seed to
that of a hazel-nut. They contain the worm, blood,
and a quantity of soft, cheesy material.

3. In the arteries (anterior mesenteric or branches of
aorta).

The eggs are laid either on or in the mucous mem-
brane. In the former case the embryo burrows into the
mucous membrane. After a while they bore their way
out into the lumen of the gut. It is supposed that some,
still in an agamous condition, again return and burrow
into a vessel. They then work against the blood-stream
to the root of the anterior mesenteric artery, and form
an aneurism there, or else get into the aorta, and are
transported by the blood-stream to other organs.
Another theory, which makes the aneurism an essential
part of the life-history of the worm, supposes that the
ova are deposited in the bowel, and are passed out into
damp ground or into water. Some consider that they
develop into free Nematodes (rhabditide), and pass this
stage of their existence in water or on damp ground.
However this may be, the majority agree that after
certain moults the embryo gets back into the intestine
by ingestion of water or food. Those which bore into
the vessels produce an aneurism in which it is believed

further development takes place, and they reach their
5

66 VETERINARY PARASITOLOGY

full size, after which they again bore back into the
intestinal wall, become encysted, and finally reach the
lumen of the intestine as the perfect adult parasite.
While in the aneurism, the parasite is spoken of as
Sclerostomum armatum minor, while the adult is spoken
of as Sclerostomum armatum major.

Sclerostomum Tetracanthum.—This is a much smaller
worm, normally white in colour, but almost invariably
bright red, from the blood contained within its body,
previously sucked from its host. It ranges from ro to
15 millimetres in length. The mouth is circular, and
the rim carries a series of teeth, together with six
papille, four large and two small. A little behind these
is another pair of long papille, placed laterally. The
tail of the male terminates in a caudal pouch, while
that of the female is pointed.

This worm also inhabits the cecum and colon of the
horse, usually in company with Sclevostomum armatum.
They are probably taken into the body with the water,
and then encyst themselves in the mucous membrane,
finally returning to the lumen of the bowel. They do
not enter the vessels and set up aneurisms.

Symptoms.—Since both of these worms are usually
found coexisting in the same horse, it is difficult to draw
any marked distinction between the symptoms set up
by either worm in particular. Since Sclerostomum tetra-
canthum confines itself to the bowel, and seldom bores,
it is less frequently the cause of the so-called vermi-
nous colic than is Sclevostomum armatum, which does
further damage in the vessels. Nevertheless, Sclero-
stomum tetracanthum, when present in large numbers, is
capable of causing marked anemia, emaciation, and
death.

The disease is commoner in the country, among horses
that have been running at grass, than in town horses, ex-
cept in those that have been recently introduced from the

PARASITES OF THE ALIMENTARY TRACT 67

country. Colts and young horses are more frequently
affected, but it is not at all uncommon to find the worms
present in large numbers, often causing grave symptoms,
in aged horses. Colts running at grass at first show
gradual emaciation, pitched coat, and general signs of
unthriftiness. As the disease progresses, weakness sets
in, and the colts acquire a stiff gait, particularly behind,
and often the joints may be heard to crack, somewhat
resembling the sound heard in some rheumatic affec-
tions. Ascites is not uncommon, but more frequently
one sees cedema of the lips, with swelling of the legs
from the hoof upwards. These symptoms arise from
circulatory changes. At intervals attacks of colic occur,
usually accompanied by diarrhcea and the passage of
large numbers of worms. Death may occur during one
of these attacks, but more often the colt gets on the
ground, and shows inability or unwillingness to rise.
In this case death soon supervenes.

The attacks of colic are due to cutting off of the
blood-supply from portions of the bowel, owing to ob-
struction or embolism of small vessels.

During the attack the animal usually lies, with the
head extended on the ground. The pain is continuous,
and may pass off as suddenly as it has come. The colt
then stands up, but may appear very dull and stupid
for some while after.

In older animals Sclevostomum tetracanthum appears
to be more commonly the cause of serious trouble than
Sclerostomum armatum.

The animal shows signs of gradual emaciation, usually
with increased appetite, but occasionally the appetite is
diminished. The coat stares and the mucous mem-
branes are anemic. Ascites is comparatively rare in
old horses. We have observed intussusception of the
bowel as a result of their presence, though a number of
Sclerostomum armatum were present at the same time.

68 VETERINARY PARASITOLOGY

In this case the ileum had entered the cecum a distance
of 2 feet.

The bowels are irregular, usually firm while in the
stable, but becoming loose when on a journey. Occa-
sionally diarrhoea is persistent. Sometimes micturi-
tion is performed more frequently than normal, from
irritation.

Death may occur from anemia, weakness, and ex-
haustion, especially in hard-worked horses.

Diagnosis is confirmed by the discovery of the worms
in the faeces, especially during the attacks of diarrhoea
or after a dose of ol. lini.

Prognosis.—This is at all times grave. If treated early
the prognosis is much more favourable; but if the
animal is on the ground, and unable to rise, then treat-
ment is seldom of any avail. When diarrhoea has set in,
the danger is much greater.

Treatment.—The first essential is rest. Vermicides
are of little use, as their dilution is too great when mixed
with the contents of the large intestine.

Thymol, in our experience, is valueless, although
regarded by many as a specific.

The only treatment of use is the administration of
hematinics over a prolonged period—at least one month
—and if the animals are treated early, recovery takes
place in go per cent. of cases by this means.

The following prescriptions we have found to have
produced the best results :

HR Ferri ammon. sulph. .. an 1. Bij.
Quinia sulph. .. ane 2 +. QYs. XV.
Acid. carbol. .. ae a -. xv.
Pulv. nucis vom. ee a +. gYs. Xx.
Pulv. quassize ts ee ee
Pulv. digitalis Ss ae aa “BTS. Xs
Pulv. glycerrh. ae a -» 8).
Theriacze 2 q.s.

M. Fiat bol. 1. Sig.: One ball to be given twice daily
for one month.

PARASITES OF THE ALIMENTARY TRACT 69

& Ferriammon. cit. .. as se Bh
Quin. sulph. .. an .. grs. XV.
Acid. hydrochlor. dil. ig 2. WXV.
Tinct. nucis vom. ee Sieg .. XV.
Tinct. digitalis mxv.
Tinct. quassize 3ss.
Aqua - ; ai .. ad Oj.

M. Fiat haust. To be cneueed every night and morning.

B Liq. ferri. marae ee poh .. Biij.
Thymol : én ath .. gYS. Xx.
Spt. vini rect. ane Fae .. Biv.
Glycerin. a i Hs .. Bij.

Ol. tereb. ix 5 sk .. Biv.
Acid. carbol. .. aa a6 .. Mxx.
Liq. calcis wis ae $4 Sy Bde

Ol. lini cag ad 3v.

M. Fiat haust. Sig.: To es given in a tat of milk, and
repeated once daily.

Providing that the animal is not suffering from
diarrhea, it is advisable to give the following draught

two days before commencing any of the prescriptions
mentioned, in order to expel as many worms as possible :

ROM. tereb. i ss ee 1. Be
Acid. carbol. .. oe es 1. Of
Ol. lini ma ae ba .. ad Oj.

M. Fiat haust.

Ferri sulph. should be avoided, as it is too irritant,
and brings on diarrhcea.

Milk, gruel, eggs, and concentrated, easily digested
foods should be given when the disease is at all advanced,
particularly if diarrhoea has set in.

In verminous or embolic colic the following draught
is most useful :

BR Spt. ether. nit. ba “% +» 5y.8s.
Tinct. digitalis a . 5-88.
Tinct. chloroformi et morph. acet. 5iij.
Acid. carbol. .. ee ae ree
Lactis .. #8 ail ae .. ad Qj.

M. Fiat haust.

70 VETERINARY PARASITOLOGY

Whenever prescribing balls in the treatment of in-
testinal parasites, it is well to paint the papers over with
a strong solution of salol in ether. The salol is in-
soluble in the gastric secretion ; solution of the contents
is retarded, and hence the agents employed reach the
intestine in a greater degree of concentration.

If the diarrhcea becomes acute, mild astringents may
be given, combined with sodium sulphite, in doses of
I to 2 ounces, as this agent appears
to exert a very marked action in
checking diarrhoea of verminous
origin. Tinct. opii is also very useful.

OXYURIDES.

The two members occurring in the
horse are Oxyuris curvula and Oxyuris
mastigodes. Oxyuris curvula is some-
times spoken of as the ‘‘maw-worm.”’
The female ranges from 4 to 5 centi-
metres in length. The body is curved,
and thickest in its anterior half, while
the posterior end tapers away into a
very thin tail.

The male is rarely seen. It is not
curved, has only a short tail, and is
only about ro millimetres in length.
It possesses a caudal pouch and a
very fine, straight spicule.

Bi, ta Oxyuris mastigodes differs from
URVULA. és 5
Oxyuris curvula in the remarkable
length of its tail, Whether it is but an abnormal form
of the former worm has been disputed.

The Oxyuride inhabit the large intestine, more
especially the floating colon, rectum, and diaphragmatic
flexure of the double colon. The eggs are deposited in
the neighbourhood of the anus in the form of a yellow

PARASITES OF THE ALIMENTARY TRACT 71

dust. Each egg is ovoid, about go p long, and provided
at one end with an operculum.

Symptoms—These are often absent. When the
worms are present in large numbers there is seen
frequent rubbing of the anus and tail, with the presence
of the characteristic yellow dust around the anus.
Occasionally there is loss of condition from irritation
and loss of rest. Oxyuris mastigodes appears to cause
more disturbance than Oxyuris curvula.

Life-History—This has not been fully worked out.
Probably there is no intermediate host, but infection by
ingestion of ova.

Treatment.—Turpentine and linseed-oil given once a
week or once a fortnight, with early-morning clysters
of infusion of quassia or common salt, given after the
rectum has been emptied by hand, usually eradicate
these parasites.

The ‘‘ worm-powders,” of which the prescription was
given when referring to Ascarides, are very useful.

Trematodes occurring in the Horse.
These are two in number:

1. Amphistomum Collinst.
2. Gastrodiscus Algyptiacus.

Amphistomum Collinsi (Masuri).—This is a worm of a
brick-red colour occurring in immense numbers in the
large intestine of horses in India. They produce great
irritation.

Gastrodiscus Higyptiacus (Gastvodiscus Sonsinoi, Gas-
trodiscus Polymastos).—This parasite has a red, oval
body, about 12 millimetres long, convex on the upper
or dorsal and flat on the ventral surface. The buccal
sucker is carried on a short proboscis, while the ventral
surface carries about 200 papillary suckers.

It inhabits chiefly the small intestine of horses, asses,
and mules in Egypt and Senegal, but may occur in

72 VETERINARY PARASITOLOGY

almost any portion of the alimentary tract. It produces
anemia and marasmus.

Treatment consists in giving vermicides and purgatives.
All land should be limed or salted, and drinking-water
filtered through fine sieves.

PARASITES INHABITING THE ALIMENTARY CANAL
OF THE OX.

Ganglyonema scutatum is sometimes present in the
cesophagus of the ox.
Stomach.

Amphistomum conicum, a Trematode, may inhabit the
first stomach. It seldom produces noticeable symp-
toms, except in Australia, where the parasite appears
to possess exceptional virulence. Various Strongyles
may inhabit one or other of the stomachs. Hence
Strongylus contortus, Strongylus gracilis, and Sirongylus
convolutus may be found in the abomasum. These will
be discussed more fully later.

Ascaris Vitulorum is sometimes seen in the abomasum
of the calf, but more frequently in the small intestine.
It is a large worm, the female reaching the length of
25 centimetres (10 inches), and the male about 20 centi-
metres (8 inches). It is of a reddish-white colour, with
a transparent skin. The head is small, and the mouth
trilabiate. It is rare in animals over two years old,
but is comparatively common in the small intestine and
abomasum of calves, particularly in the South of France.
The embryos are the more active in producing the disease.
The commonest symptoms are those of colic and indi-
gestion. A few worms may be passed with the feeces.
Perforation or rupture of the abomasum has frequently
been recorded.

Treatment.—Calomel, areca-nut, turpentine, and lysol
are favourite remedies, and should he followed by
linseed-oil or saline purgatives,

PARASITES OF THE ALIMENTARY TRACT 73

Small Intestine.
CESTODES OF THE OX.

The three tapeworms inhabiting the ox belong to the
Anoplocephaline, or unarmed worms. These have the
genital pore double in each segntent, all of which are
much broader than long.

The three tapeworms are:

I. Tenia expansa.
2. Tenia alba.
3. Tenia planissima.

Tenia Expansa.—This is the commonest and also the
largest tapeworm of the ox. It ranges in length from

Fic. 18,—HEAaAD oF T2NIA Fic. 19.—HEAD oF TANIA
EXPANSA. ALBA.

25 to too feet. The anterior segments are narrow,
but the ripe posterior segments are very short, and are
usually an inch wide. The head is small and slightly
flattened, and the suckers are arranged in the form of
four oval slits.

Tenia Alba.—Next to Tenia expansa, this is most
commonly found. It averages about 6 feet in length,
and the widest segments reach from 3 inch to 2inch. The
segments are proportionately longer than those of Tenia
expansa, and are of a dense whiteness. On holding the

74 VETERINARY PARASITOLOGY

worm between the eyes and the light an opaque line
may be seen running the whole length of each segment,
about $ inch from the edge. The head is large, and
extends beyond the adjoining segments, while the
suckers, unlike those of Tenia expansa, are round.

Tenia Planissima, or Denticulata.—This worm ranges
from 3 to 6 feet in length only, and is characterized by
a serrated edge, which is due to the overlapping of each
anterior segment. The head is by no means large, and

the suckers are slightly elongated.
5 Symptoms.—The presence of
| tapeworms in the ox is seldom
suspected until some have been
passed with the feces. If in large
numbers, they may cause anemia,
loss of condition, depraved appetite,
and diarrhcea. By coiling them-

Fic. 20.—Heap oF selves together into a ball, they
Tania DENTICULATA. : : :

may cause intestinal obstruction.

Treaiment.—As these worms are unarmed, vermicides
and purgatives will remove them with little difficulty.

Lysol, turpentine, male-fern, areca-nut, given in
linseed-oil, are quite efficient.

Arsenic, in doses of ro grains daily, may be given to
oxen for three or four consecutive days.

Strongylus Ventricosus.—This worm is the inhabitant
of the small intestines of cattle and deer. It is a com-
paratively small worm, the female reaching only
12 millimetres in length, and the male 6 to 8 millimetres,

In the male there is a broad caudal pouch, which is not
distinctly trilabiate.

In the female the vulva is situated just behind the
middle of the body, and is surrounded by a pouch.
Professor Penberthy has associated this worm with cases
of parasitic gastro-enteritis in cattle and sheep, while
other observers regard it as producing no ill-effects.

- = SS

PARASITES OF THE ALIMENTARY TRACT 75

CESOPHAGOSTOMES.

Gsophagostomum Columbianum.—This parasite is the
cause of the so-called “‘ pimply gut,’’ which is more
common in America. It is occasionally seen in this
country, infection taking place through the spreading
of manure brought from other countries.

The male is } inch and the female 3 inch long. The
whole of the life-history is unknown.

The eggs are laid in the intestine, and pass out with
the feeces.

The embryos are found in small tumours, from the size
of a pin’s head to a pea, under the mucous membrane.
They possess no boring apparatus, so that some doubt
exists as to the precise manner in which they gain their
position. In these nodules the embryo moults, and
develops until it reaches about 4 inch in length, when the
nodules burst, and the worm is set free.

The intestines must not be used for preparing sausage-
skins.

Csophagostomum Inflatum is not so common.

STRONGYLES INHABITING THE ALIMENTARY CANAL
OF CATTLE, SHEEP, AND DEER.

These are of especial importance, as they cause very
serious wasting disease, accompanied by great mortality.
The Strongyles inhabiting the stomach and intestine of
ruminants are :

Strongylus cervicornis.
Strongylus contortus.
Strongylus filicollis.
Strongylus vicarius.
Strongylus MacFadyensis.
Strongylus convolutus.
Strongylus gracilis.

WORE DH

79 VETERINARY PARASITOLOGY

To detect the presence of these worms after death, the
abomasum or a piece of intestine should be opened and
emptied ofits contents. A scraping of the mucous mem-
brane should then be taken and mixed in a watch-glass
with water, placed while in this receptacle on the stage of
a microscope, and examined with a low-power objective.
A magnification of x50 is ample. If the watch-glass is
placed on a piece of black paper, in a good light, the
parasites may be more readily discovered. In addition
to the adult worms, ova and embryos may be discovered.

A brief description of the more important of the
above-mentioned parasites will suffice.

Strongylus Cervicornis inhabits the abomasum of
cattle and the intestine of sheep and lambs.

It causes great mortality—even as high as 20 per cent.
Its colour is a greyish-white. The male is 7 millimetres
long. It has a caudal bursa, supported by dichoto-
mously branched chitinous rays. The female is
ro millimetres long.

Strongylus Contortus inhabits the abomasum of
cattle and sheep. It is of a reddish colour, owing to the
blood of its host contained within it.

The male is 10 to 20 millimetres in length, and the
female ro to 30 millimetres.

The male has a bilobed caudal bursa, with a small
unilateral accessory lobe.

The oviducts of the female are contorted, and wound
around the intestine.

Strangylus Filicollis inhabits the abomasum of
cattle and sheep, and commonly the small intestine.
The anterior portion is tapered into a neck.

It is smaller than Strongylus contortus.

Strongylus MacFadyensis is similar, but smaller.

Strongylus Convolutus inhabits the abomasum of
cattle and sheep. The male has a bilobed caudal bursa,
with four rays in each.

PARASITES OF THE ALIMENTARY TRACT 77

This worm lives coiled up in nodules in the mucous
membrane.

Strongylus Gracilis affects cattle, sheep, horses, and
pigs. It is dull white in colour. It possesses a tapered
anterior extremity, like Strongylus filicollis, but is
smaller.

The female is only 3 to 4 millimetres in length.

Symptoms.—Parasitic gastro-enteritis is more often
seen in young animals, such as yearling cattle and
lambs, especially when a wet winter follows a dry
summer. It is characterized by progressive emaciation,
diarrhoea, and anemia.

Young cattle affected show all the symptoms of
catarrhal gastritis and enteritis. Diarrhoea is a marked
symptom, and wasting is very rapid. The feces are
watery, black, and foetid. The animals refuse food, but
exhibit great thirst, and show signs of stomach irritation,
such as licking sand or soil. The temperature is elevated,
and 105° or even 108° F. is by no means uncommon.
The cattle appear tucked up and hidebound, and the
mucous membranes are pale and anemic. Finally, the
temperature becomes subnormal, and death takes place
from exhaustion.

The course of the disease is usually from one to
three weeks, but may be only from one to three
days.

In sheep the disease presents similar symptoms, but
the mortality is even greater.

It is extremely common to find husk present at the
same time.

Lesions.—On post-mortem examination, the mucous
membranes of the abomasum and small intestine are
found in a condition of catarrhal inflammation. Ulcera-
tion may be present, or the mucous membrane may be
easily removed by slight friction. A submucous gela-
tinous exudate is commonly present.

78 VETERINARY PARASITOLOGY

The external mucous membranes are anemic. Ascites
is occasionally seen.

On making a microscopical examination, hundreds of
Strongyles may be discovered.

Prognosis.—Animals badly affected with parasitic
gastro-enteritis seldom recover unless treated, and even
then with difficulty.

Prophylaxis.—The parasites which cause these symp-
toms must necessarily pass a certain period of their
existence amid damp surroundings, and they undergo
certain modifications outside the host.

All affected pastures should be drained, salted, limed,
or ploughed. If possible, they should be kept free from
cattle. Overcrowding must be avoided, and lambs and
yearlings should be well fed and kept in good condition,
in order that they may withstand the attacks of
Strongyles. As preventives, salt and general tonics
may be given in the food. Lambs must never be placed
on affected ground after adult sheep, as the latter may
act as a host and yet be unaffected, and may pass
the disease on to younger animals, with disastrous
results.

Treatment.—Afiected animals should be isolated, and
the whole herd or flock dosed, as a preventive measure,
three times, at intervals of three days.

The following drench is suitable for lambs :

R Ol. tereb. ae ae we oe Of
Chloroformi } oa
Lysol ‘os ~ oe .. 4a mx.

M. Fiat haust. Sig.: To be given in milk.

Picrate of potash, up to 5 grains per lamb, is also very
successful.

In cattle lysol has proved most useful. As a prelimi-
nary 4 drachms may be given, either by bottle or
probang.

PARASITES OF THE ALIMENTARY TRACT 79

Professor Penberthy recommends the following :

BR Lysol me aie “5 ss Bij.
Chloroformi .. 64 Ae -+ Bij.
Ol. tereb. 3 ; aig “BJ «SS:

M. Fiat haust.

This should be followed by tonics and anthelmintics,
such as iron, salt, bitters, as gentian or asafcetida.

Trichocephalus Affinis.—This worm inhabits the cecum
of the sheep, goat, and ox. It belongs to the Tricho-
trachelide, and is characterized by the cephalic
extremity being drawn out into a thread. It is thus
exactly opposite to Oxyuris curvula, in which the caudal
extremity is filiform. The anus is terminal. The
worm attaches itself by its head, and rolls the remainder
of its body spirally into a ball. The male has a genital
spicule, and the length ranges from 6 to 8 millimetres.

There is no intermediate host required in the life-
history of this parasite. The whole cycle is completed
in a little over a fortnight.

Symptoms.—These worms are seldom the cause of
serious trouble in cattle, unless present in very large
numbers. In sheep they often set up muco-enteritis.
Occasionally they are seen in emaciated, anemic cattle,
which are also probably the host of numerous other
varieties of parasites.

Treatment.—lf detected in the feces, purgatives or
a course of astringent tonics, such as ferri sulph., will
be sufficient.

The only other parasite worthy of note as being
found in the large intestine is Amphistomum tubercu-
latum. This is, however, very unimportant.

Protozoa inhabiting the Intestine.
As this volume is intended only to give a description
of the macro-parasites, it is only necessary to give a
brief account of the Coccidia and the disease (psoro-

80 VETERINARY PARASITOLOGY

spermosis) which they produce. Coccidium Zurni is
responsible for outbreaks of dysentery in young cattle
and lambs, while Coccidium oviforme produces similar
symptoms in rabbits. Sir John MacFadyean found
Coccidia in cattle indistinguishable from Coccidium
oviforme. The Coccidia are ovoid in shape, and possess
an outer envelope, which gives the parasite a double
contour when examined microscopically.

The contents of the capsule or envelope are granular,
and may assume various forms and positions, according
to the stage of development.

The length is 18 to 25 yw, and width about 13 p.
Desiccation destroys the Coccidia, and they are therefore
prevalent on low-lying, marshy ground.

Symptoms.—At first the animals void greenish-black,
foetid, liquid feeces, and there is no straining and little
constitutional disturbance. In a few days this gives
way to dysentery, with a large proportion of blood
mixed with the feces. The animals now appear dis-
tressed, strain forcibly for some minutes after defecation,
arch the back, and may show colic. There is loss of
appetite and absence of thirst, and emaciation sets in
very rapidly. The course of the disease lasts about a
week. Mortality may be anywhere from Io to 25 per
cent.

Lesions.—These are present in the whole length of the
large intestine. The bowel is empty, the mucous mem-
brane inflamed and discoloured, thickened and ridged,
and shows areas coated with a thick tenacious layer of
mucus. On removing this, the mucous membrane
beneath appears whitish and shows depressed ulcers.

On microscopical examination of a section the
parasites are seen to have invaded the crypts of
Lieberktihn, and to be present both in the lumen of the
ducts and in the cells themselves. The interglandular
connective tissue is infiltrated and thickened.

PARASITES OF THE ALIMENTARY TRACT 81

Tveatment.—Prophylaxis consists in draining the
land. All feces from affected animals should be dis-
infected and destroyed. Fields in which the disease
exists should be avoided during the hottest months of
the year.

Therapeutic treatment consists in giving internal
antiseptics, as lysol, creolin, salol, etc., together with
alkalis and mild astringents, given in mucilaginous
drinks.

An ample supply of concentrated, easily digestible
nourishment is essential.

Tapeworms in Sheep.

These are very common, and the sheep, next to the
dog, is the most frequently infested of the domesticated
animals.

As in the ox, there may be present :

I. Tenia expansa.

2. Tenia alba.

3. Tenia denticulata ; sometimes spoken of as Tenia
ovilla.

4. Tenta fimbriata, or Thysanosomum actinioides.

Thysanosomum Actinioides. — This parasite is also
spoken of as the fringed tapeworm, as the posterior edge
of each segment is quite visibly serrated. The genital
pore is double in each segment.

The head is quite distinctive. It carries four slit-like
suckers, placed exactly at the four corners.

Sympitoms.—This disease in sheep is very prevalent
and of great importance in North America. In Sep-
tember and November the lambs fail to make the
progress they should do, Catarrhal enteritis sets in, as
a result of irritation, and the worms invade the bile-ducts.
Jaundice results, and the infected lambs are small,
dropsical, and badly nourished.

6

82 VETERINARY PARASITOLOGY

Treatment. — Arsenic, 3 grains, with areca - nut,
I5 grains, should be given once daily for a week, and
followed by a purgative. Potassium picrate, 10 to
20 grains, once daily, or naphthalin, 20 grains, may be
used. Other agents used are kamala,1 drachm, twice
daily, male-fern, and
lysol.

Lambs should be
kept off infected pas-
tures, and these should
be drained and dressed
with sulphate of iron,
lime, or salt.

Ascaris Ovis.— One
or two cases have been
recorded, but the para-
site is rare.

Sclerostomum Hypo-
stomum.—This para-
site is an inhabitant
of the large intestine
of the sheep and goat.
It lives in small nodules in the mucous membrane. Its
length is r inch (female) ; the male is smaller. The body
is stiff and white, and the head is rounded, but is
obliquely cut off on one side. The mouth is armed with
teeth.

Symptoms.—Anemia, gastro-enteritis, and dysentery.
On the whole, the symptoms resemble almost precisely
those produced by Sclerostomes in the horse.

The mucous membrane of the intestine is chocolate-
coloured, and shows nodules. Many cases prove fatal.

Treatment. — Thymol, turpentine, and linseed-oil ;
lysol, salol, etc., may be used,

Fic. 21.—HEAD AND SEGMENTS OF
Ta@nNIA FIMBRIATA.

PARASITES OF THE ALIMENTARY TRACT 83

PARASITES INHABITING THE ALIMENTARY
CANAL OF THE PIG.

In the cesophagus Ganglvonema scutatum may be
found.

Small Intestine.

Echinorhyncus Gigas.—This worm belongs to the
Acanthocephala, or thorn-headed worms. It is cylindri-
cal in shape, and of comparatively large size. The male
reaches Eo centimetres in length, while the female
ranges from 30 to 40 centimetres.

The head carries a retractile proboscis, armed with a
large number of hooks, arranged in transverse rows.
The body is greyish in colour and of variable diameter
throughout its length.

The male possesses a bell-shaped caudal pouch, while
in the female the caudal extremity is blunt and rounded.
The life-history has not been clearly demonstrated,
but it appears that after the ova, which are elliptical
in shape, have left the pig, the immature embryos are
ingested, while contained in the larve of insects ; as in
the May-bug, cockchafer, or even in the bodies of certain
snails.

The worms may be free in the intestine, but usually
are attached by the head, which is buried in the mucous
membranes. Sometimes the worm bores deeply into
the mucous membrane, and on being removed leaves a
scar. Perforation, with subsequent traumatic peri-
tonitis, is not rare.

These worms are not common in the United Kingdom,
but are of very frequent occurrence in France, Germany,
and the United States.

Symptoms.—These vary according to the number of

84 VETERINARY PARASITOLOGY

worms present. If they are but few in number, the
symptoms may be nil. If present in large numbers,
there is anorexia and constipation, with a varying
degree of colic, signs of irritation, such as rubbing on
the ground or biting at the hind-quarters, together
with epileptiform convulsions, spasms, and twitching.
These symptoms are accompanied by progressive
emaciation.

Post-mortem Appearances.—When badly infested, the
piece of intestine, when grasped in the hand, feels as
though it were filled with a number of large shot,
while small centres of suppuration may frequently be
seen on looking through the serous surface. These
have the head of the worm in the centre. The
remainder of the mucous membrane may present the
usual appearance of catarrhal inflammation. Ulcers are
common, and they may reach, or even perforate, the
serous coat.

Treatment.—Ordinary vermicidal treatment may be
employed when the number of parasites present is small.
When complications ensue special treatment must be
resorted to.

As a vermicide, ol. tereb. is useful in 2-drachm doses,
given in milk. Aperients should also be given. Aloes,
1 drachm, is probably the best.

Ascaris Suis.—This large worm inhabits the intestine
of the pig. In appearance it much resembles the Ascaris
lumbricoides of man, and often reaches a length of
Io inches.

It is not very common, and may produce no very
marked symptoms. If present in large numbers, the
worms may cause intestinal obstruction, with colic.
Epileptiform spasms and convulsions have also been
noted.

Treatment.—Santonin or areca-nut is usually effi-
cacious, and should be followed by a purgative.

PARASITES OF THE ALIMENTARY TRACT 85

The Tenia are not represented in the intestine of the
pig.

A whip-worm, Trichocephalus crenatus, is occasion-
ally present.

INTESTINAL PARASITES OF THE DOG AND CAT.

Ollulanus Tricuspis is sometimes found in the ceso-
phagus of the cat.

Stomach.

Spiroptera Sanguinolenta.—These worms may occur
in the pharynx, cesophagus, and stomach of the dog,
where they form clusters of nodules. They are more
common in Italy than in any other country, and there
they cause in the host a form of gastritis. They fre-
quently penetrate to the bronchial glands, causing
hypertrophy, with suppuration. They have been seen
in the walls of the aorta.

Spiroptera sanguinolenta is a blood-red worm. The
female measures 6 to 8 centimetres, and the male about
half that length. The so-called “ blackbeetle”’ is
believed to act as an intermediate host in the life-cycle
of this parasite.

Ollulanus Tricuspis is found in the cesophagus of the
cat.

Intestine.

Protozoa, as Coccidium bigeminum, may exist between
the villi, but the symptoms they set up are usually
slight.

CESTODA OF THE ])0G.

Next to the sheep, the dog is, of all the domesti-

cated animals, the most frequently infested with

tapeworms.
The Teenie found in the dog are eight in number,

86 VETERINARY PARASITOLOGY

and there may also be present three Bothrioce-
phalide.

; Tenia serrata.
Tenia marginata.
Tzenia echinococcus.
Tenia serialis.
Tenia coenurus.

| Tenia Krabbei.

Six Cystotenize

One Dipylidium .. Dipylidium caninum, or Tenia cucu-
merina.
One Mesocestoides .. Mesocestoides lineatus.

Bothriocephalus latus (Europe).
Three acl Bothriocephalus cordatus (Greenland).
Bothriocephalus fuscus (Iceland).

Fic, 22.—T4NIA SERRATA.

a, Head; b, c, d, segments,

Lije-History.—All the Cestoda are hermaphrodite,
but fertilization nevertheless takes place. Either by
rupture of the proglottis or by extrusion through the
genital pores, the ova are liberated, and hatch into

PARASITES OF THE ALIMENTARY TRACT 87

embryos, all of which are armed with three pairs of
hooks.

The embryo of each variety of tapeworm requires
a special host, and in the event of being unable to
find this it dies. When ingested, it is carried by the
blood-stream to some organ, such as the liver, or even
to the brain in some cases, and becomes encysted. The
Dipylidium found in the dog is interesting, as the inter-
mediate host is an invertebrate, as a louse or flea.

The cysts just mentioned are not all alike. There are
three varieties : Cysticercus, Coenurus, and Echinococcus.

In Cysticercus the cyst has only one cavity, and con-
tains only one head, or scolex,
attached to its inner wall—z.e.,
it is monosomatic and mono-
cephalic.

In Coenurus the cyst is
multilocular, and each loculus
contains one scolex—i.e., it is
polysomatic and monocephalic.

In Echinococcus the cyst is
multilocular, and each loculus
contains several scolices—7.e.,
it is polysomatic and poly- :
cephalic. Fic. 23.—T@nNia SERRATA:

The whole cycle may take Hooxs.
from two to eight months.

Teenia Serrata.—This is one of the commonest tape-
worms found in the dog. The length varies from 1 inch
to 6 feet. The head is a little wider than the neck,
and is armed with from thirty to forty hooks, which are
of two classes, large and small. The latter possess a
bifid guard. The segments are much longer than wide,
and the posterior edges are widest, making a serrated
edge. The genital pores are characteristic. They
are arranged on alternate sides, and each is very

88 VETERINARY PARASITOLOGY

prominent and forms a marked convexity. The uterus
is a long median tube, and has a number of lateral
branches, which are given off after the manner of an
umbel.

The cystic stage takes the form of a Cysticercus, the
Cysticercus pisiformis, which is found attached to the
mesentery of rabbits or situated in some other portion of
the peritoneal cavity.

The Cysticercus pisiformis is of the size and shape of
a pea, and shows on inspection the invaginated head,
which exactly corresponds in structure with that of
Tenia serrata. Occasionally a Cysticercus pisiformis is
found elongated in shape, and even a few segments may
be present behind the head.

A dog may become infected by ingestion of the cysts,
eight to ten days after desiccation. The cycle is com-
plete in eight weeks, when the dog will be voiding ripe
segments and ova.

Tenia Marginata.—This is also a fairly common
parasite of the dog’s intestine. It is a large worm, and
is only with difficulty to be distinguished from Tenia
serrata. Its length is from 4 to 6 feet.

The head is not wider than the neck, and so does not
project on either side. It carries from thirty to forty-
four hooks. In Tenia marginata the guards of the
hooks are not bifid, as in Tenia serrata, but S-shaped.
The segments of the anterior portion are much broader
than long, but in the terminal half the reverse is the
case, though even then they are broader and shorter
than those of Tenia serrata, and the posterior border
of each segment shows a somewhat wavy outline. The
genital pore is much less prominent, and the outline is
therefore more regular.

The cystic form is a Cysticercus, the Cyszicercus
tenuicollis, which is found in the peritoneal cavity, and
occasionally in the thorax of sheep, oxen, and some-

PARASITES OF THE ALIMENTARY TRACT 89

times in pigs. The Cysticercus may be the size of a
pigeon’s or hen’s egg, and is pedunculated, possessing a
long, narrow neck or stalk, by which it is attached.
This parasite has been responsible for fatal outbreaks
of hemorrhagic hepatitis in lambs, owing to migration
from the intestine, through the bloodvessels and liver,
into the peritoneal cavity. The occasional presence of

Fic. 24.—T#£NIA MarGINaTA.

a, Head; b, unripe segments; ¢, ripe segments ;
d, hook ; e, Cysticercus tenuicollis,

small cysts in the muscles of the sheep has given rise
to the term “‘ pseudo-measles of the sheep.”

In pigs a similar condition is seen, particularly affect-
ing the muscular pillars of the diaphragm.

Tenia Echinococeus.—This is the smallest tapeworm
of the dog, and never exceeds four segments. The head
is armed with a double row of hooks, by means of which
the parasite attaches itself to the mucous membrane

90 VETERINARY PARASITOLOGY

of the intestine. In other cases the worms lie free in
the bowel lumen. In length it ranges from 4} to 1 inch.
The terminal segment is by far the largest, and contains
the mature ova.

The cystic form is the Echinococcus veierinorum,
which may be found in various organs of the body—
liver, lungs, ovaries, etc.—in cattle, pigs, and other
animals.

The cysts may be single or multi-
locular, and may be few in number or
present in sufficient quantity to com-
pletely deform the organ in which they
are contained. Their contents consist
of clear, limpid fluid.

A cyst-infested liver in the ox may
weigh Ioo pounds.

Tenia Serialis—This worm seldom
exceeds 2 feet in length, and is not very
commonly found.

The head carries twenty-five to thirty
hooks, the smaller ones having bifid
guards. The segments are long and
narrow. The intermediate host is a
rodent, such as a rabbit or hare, and
the Ccenurus is found attached to
connective tissue, often between the
muscles, or occasionally in the brain.

Unlike Cenurus cerebralis, this cyst
frequently buds off internal or external daughter cysts,
containing numerous scolices. This cyst does not pro-
duce gid in sheep, even when attempted experimentally.

Tenia Coenurus.—In length this worm seldom exceeds
zt yard. Itis not common. The head bears twenty to
thirty hooks. The segments are very much wider than
long, and much resemble those of Tenia serialis. The
uterus gives off about twenty ramifying branches.

Fic. 25,—TNIA
EcHINOCOCCUS.

PARASITES OF THE ALIMENTARY TRACT ot

The cystic form is Cenurus cerebralis, which develops
under the dura mater of the sheep’s brain, and occa-
sionally of cattle, and in rare instances that of the horse,
producing the so-called sturdy, or gid.

The Cenurus cerebralis sometimes attains a com-
paratively large size : cysts of the volume of a hen’s egg
are not uncommonly met with. The contents are
limpid and colourless. The surface shows scattered
clusters of dense white spots, representing invaginated
scolices.

The ova or terminal segments of Tenia cenurus are
ingested by a lamb, and the outer coverings become
dissolved in the stomach. The embryos are set free,
and bore into a small vessel, whence they are carried to
various organs of the body. Those which reach the
brain gradually develop into Ccenurus cysts.

They have also been described as occurring in other
organs and tissues.

Tenia Krabbei—Not found in this country. Seg-
ments wider than long. Genital pore occupies the whole
of the lateral edge of each segment.

The cystic form is a Cysticercus, and has been seen in
the muscular tissues of reindeer.

Tenia Cucumerina, or Dipylidium Caninum.—This
worm, as its less common name indicates, is a Dipylidium,
having its genital pores situated on each side of each
segment. It is about 16 inches in length, and is a very
common inhabitant of the dog’s intestine. The head is
larger than the neck, rounder in shape, and bears a
protractile rostellum, armed with several rows of hooks.

The segments are elliptical in shape, and resemble
cucumber-seeds joined end to end. The cystic stage is
passed in one of the external parasites of the dog, such
as the flea or louse.

Bothriocephalus Latus is unarmed, having no hooks.
The genital pores are central in each segment.

92 VETERINARY PARASITOLOGY

The length varies from ro to 20 yards. The head is
lanceolate in shape, and in place of suckers carries two
long canals, or bothria. The segments are much wider
than long. When ripe, the terminal segments shrivel
and remain attached for a while. They are practically
empty of ova. In this worm actual ovulation takes
place, the eggs being extruded from the central opening.

The intermediate host is a perch or pike. This worm

Fic. 26,—T#NIA CUCUMERINA. Fic. 27.— BoTurRio -
CEPHALUS LaTUS.

may inhabit the intestine of man or the dog in countries
where sanitation is neglected and sewage drains into
lakes or rivers.

Mesocestoides Lineatus also has the suckers centrally
placed in each segment. It is much shorter, only
averaging 18 inches in length. The segments resemble
those of Tenia cucumerina. Instead of bothridia,
Mesocestoides lineatus has four ordinary suckers, opening
by slits.

Life-history not fully worked out.

PARASITES OF THE ALIMENTARY TRACT 93

Tapeworms in the Cat.

There are four tapeworms which may be found in the
cat.
These are :
1. Dipylidium, Tenia elliptica.
2. Tenia crassicollis.
3. Afesocestoides lineatus.
4. Bothriocepbhalus felis (very rare).

Tenia Elliptica——This worm is practically identical
with Tenia cucumerina of the dog.

Teenia Crassicollis——This worm is peculiar to the cat.
It is a comparatively short worm, seldom exceeding
2 feet in length, and more commonly only reaching
5 or 6 inches. The head is rounded and of the same
diameter as the neck. It possesses four suckers, anda
rostellum carrying thirty to fifty hooks, arranged in a
double row. The terminal segments are longer than
wide. The cystic form is the Cysticercus fasciolaris,
which occurs in-rats, mice, and other rodents, more
commonly situated in the liver. This Cysticercus
possesses several. interesting characters. In length it
may reach 6 inches, and may thus be mistaken for the
mature form of some parasite. The head is invaginated,
and is succeeded by a number of segments, and at the
other extremity there is a small bladder, with the
diameter of a pea.

Mesocestoides Lineatus.—Probably is identical with
the Mesocestoides found in the dog.

Signs of Tapeworms.—These are often absent, except
when the worms are present in considerable numbers.
The signs then noticeable are capricious appetite, at
times ravenous, with loss of weight, staring coat, signs
of irritation, such as drawing the anus along the ground
- and barking or yelling during sleep. In some in-

94 VETERINARY PARASITOLOGY

stances the dog will betray signs of excitement, and
even mania, and act as though hunting imaginary mice,
and scraping at floors and boarding. Epileptiform fits
and convulsions are common.

Occasionally the symptoms are such as to cause one
to suspect rabies. These are excitement, epileptic fits,
and paralysis of the lower jaw, followed by periods of
depression. Continual snapping together of the jaws
is not uncommon.

On post-mortem examination in badly infested intes-
tines the lesions discernible are those of chronic catarrh
of the bowels, together with the presence of tapeworms,
chiefly in the ileum and jejunum.

Treatment.—The agents now in general use in canine
practice are various preparations of areca-nut. The
dry extract, dissolved in glycerin, is most efficacious.
All remedies must be given fasting, and preferably in a
small quantity of milk.

Extract of male-fern ranks next, in doses of 10 to 80
grains.

Grated areca-nut, 2 grains per pound body-weight
up to 2 drachms, is a favourite remedy.

Calomel, kamala, kousso, creolin, ol. tereb., and
various other agents, each have their supporters.

Ascarides.

In the dog: Ascaris marginata.
In the cat: Ascaris mystax.

Ascaris Marginata is a frequent inhabitant of the small
intestine of dogs, and particularly of puppies. Length,
I to 5 inches.

The body is cylindrical, stiff, and curved. The head
bears two membranous wings. In the male the tail
curves sharply upwards and carries two smaller wings.

Ingestion of ova is the means of infection. Pups

PARASITES OF THE ALIMENTARY TRACT 95

are frequently born with Ascarides, though no satis-
factory explanation is forthcoming. Pups, when
affected, show a harsh, staring coat, pot-belly, capricious
appetite, and often intermittent diarrhoea and vomiting.
The vomit occasionally contains one or more Ascarides.
Nervous symptoms are usually in evidence when the
number of Ascarides present is large. These are repre-
sented by twitching of groups of muscles and epileptiform
convulsions. Deathin pups from these parasites is quite
common. Incontinence of urine is another frequent
symptom.

We have seen several cases of intestinal intussuscep-
tion due to Ascarides.

In older dogs the symptoms are less pronounced,
though nervous symptoms are not uncommon.

Treatment.—Santonin is considered a specific, but
must be used with caution. Pups should receive
$ to 2 grains, with 2 to 5 grains calomel.

Syrup. ferri iod., given daily for a week, is much
safer and quite as efficacious.

Older dogs may receive santonin, 2 to 5 grains,
according to weight and breed.

Ext. filix mas and grated areca-nut are also used.

Ascaris Mystax resembles Ascaris marginata, but is
smaller, and the wings on either side of the head are
quite easily visible to the naked eye.

Symptoms and Treatment.—As in the dog.

Ankylostomum ‘Trigonocephalum.— This worm is
sometimes found in the small intestine of the dog and
cat.

It ranges from } to # inch in length, and is usually
reddish in colour, from ingested blood. The caudal
pouch of the male consists of two large lateral lobes
and a small median lobe. The mouth is chitinous, with
three hooked teeth at either side of the ventral border
and one straight tooth at either side of the dorsal border.

96 VETERINARY PARASITOLOGY

In both sexes there is a right-angled bend close behind
the head.

Symptoms.—Debility, weakness, and general signs of
pernicious anzemia are present.

The skin becomes scurfy, and ulcers arise on the
skin of the limbs, which is often cedematous. The nose
becomes excoriated, cracked, and sore.

Epistaxis sets in in the later stage, and several ounces
of blood may be lost at one time.

Diarrhoea becomes persistent, and leads to dysentery.
Finally the animals grow very weak, constantly lie
about, and finally become comatose and die.

A whole kennel may be affected at one time, and the
disease is common in packs of hounds in some countries.

On post-mortem examination, after careful search
the worms may be discovered. The mucous membrane
is thickened, raised, and red in patches, and shows
petechiz.

There is usually marked enlargement of the mesen-
teric lymphatic glands.

Treatment—This form of helminthiasis spreads
rapidly, so that isolation of affected animals is essential.
Sanitation must be improved, and great care taken in
the cleansing of all feeding utensils.

The usual anthelmintics may be employed.

Filix mas or kamala, with calomel, are useful.

After expulsion of the worms, a course of syrup. ferri
iod. or ferri arsenas should be given. Syr. Eastonii
might be useful.

Above all, nourishing, easily digestible food is
essential.

CHAPTER III
PARASITES WHICH INVADE THE LIVER

THERE are two channels by which parasites, in some
stage of their life-history, may reach the liver. The
easiest way is by passing from the duodenum up the
bile-ducts, while the other is by boring through the
intestinal wall into one of the branches of the portal
system, and so being carried thither in the blood-stream.
By the first route blocking of the bile-ducts is common,
and this is accompanied by symptoms of jaundice and
in chronic cases ascites.
The parasites which may invade the liver are :

1. Linguatula denticulatum.

2. Coccidia.

3. Cystic forms of tapeworms.
4. Trematodes.

1. Linguatula Denticulata.—This is the larval form of
Linguatula tenoides of the dog, encysted in the liver
of one of the Herbivora. It possesses four pairs of
rudimentary legs, and after going through a moult
becomes annulated, the rings possessing series of spines,
resembling those on a bot. They remain in the liver
several months.

They may also be found in the mesenteric glands or
even in the lung.

2. Coccidia in the Liver.—Coccidium oviforme may
affect calves, lambs, young pigs, etc.

97 7

98 VETERINARY PARASITOLOGY

The Coccitdium cuniculi of the rabbit is identical, and
these rodents act as harbourers and carriers of the
parasite.

3. Tenia Cysts in the Liver.—Tenia may be present
in the liver, as embryos passing through on the way
to the peritoneum or encysted therein. Of the former
Cysticercus pisiformis may be taken as an example.
These cysts invade the liver of rabbits in the form of
miliary nodules, greyish in colour, with thick envelopes,
guite distinct from the thin walls of the Coccidium cysts.

They remain in the liver from three to four weeks
before escaping into the peritoneal cavity.

Echinococcus Veterinorum.—This is the cystic stage
of Tenia echinococcus of the dog, and is common in the
liver of the ox, sheep, pig, and many wild animals. It
may also occur in the lungs, heart, kidneys, and brain,
in the intermuscular connective tissue, or in almost any
organ or tissue.

The cyst takes six months to fully develop, and may
range in size from a pea to a pumpkin. It possesses
two layers—an outer thick envelope, known as the
ectocyst, and an inner thin layer, the endocyst. The
fluid contained is clear and serous, but free from albumin.
Many are sterile, and contain no scolices.

Echinococcus cysts may be single or multiple, from
external or internal budding. The latter method is
commoner in man than in the Herbivora.

A liver thus infested is more or less enlarged, according
to the number of cysts present. A hundredweight is
not an uncommon weight for a badly affected ox-liver,
and in this there may be present several thousand cysts.
A pig’s liver may reach half this weight. The liver
in these advanced cases is usually found firmly adherent
to the neighbouring organs, such as the intestines, or to
the diaphragm or omentum. On section the tissues
may appear to be one mass of cells, resembling a honey-

PARASITES WHICH INVADE THE LIVER 99

comb, or may contain only a few cavities of varying
size. The portions of liver between the cysts become
atrophied from pressure. Old cysts may show signs of
calcification, with pus in the centre.

These must not be mistaken for lesions of tuberculosis,
and may be distinguished by the discovery of scolices on
microscopical examination, by the existence of vestiges
of the envelopes in the calcified cysts, and by the absence
of tubercle bacilli.

Symptoms.—Otten there are no apparent symptoms.
When in sufficient numbers to cause marked enlarge-
ment of the liver, percussion in the neighbourhood of
the last two ribs on the right side will often assist
diagnosis. On palpation pain may be evinced. Diges-
tion is disturbed and emaciation becomes marked.
Jaundice is seldom exhibited. Diarrhcea is not un-
common. On rectal examination the liver may be
found enlarged and lumpy.

Treaiment.—Useless. Slaughter when the diagnosis
is confirmed is the most economical course if the number
of cysts in any one organ is great.

DISTOMIASIS (FLUKE DISEASE, FASCIOLIASIS,
LIVER ROT, ETC.).

Distomiasis is the name given to the condition arising
from the existence of Distomata, or flukes, in the bile-
ducts of the liver. It affects oxen, sheep, and goats.
There are two species which may set up the condition—
viz., Distomum hepaticum and Distomum lanceolaitum.

Distomum Hepaticum.—The parasite isleaf-shaped and
of a dirty white colour. In length it varies from 20 to
30 millimetres, and in width from 10 to 15 millimetres.
The anterior extremity is more or less rounded, except
at the extreme tip, which is drawn out into a short

100 VETERINARY PARASITOLOGY

projection, on which is situated the oval sucker. The
posterior extremity tapers almost to a point. The
suckers are two in number—an oval sucker, rounded
in outline, and a ventral sucker, situated about 3 milli-
metres behind it, which is larger and triangular. The
alimentary organs, which are visible when the para-
site is held between the eye and the light, consist
of two main lateral branches, from which arises on
either side a much-branched system. The parasite
is hermaphrodite.

The testicles are profusely branched,
and occupy the middle third of the
body. The uterus is situated imme-
diately behind the ventral sucker,
and opens by a short vagina on the
ventral surface of the body, between
the oval and the ventral suckers.

Distomum Lanceolatum is not found
in this country. It is narrower than
Distomum hepaticum, and the two
lateral alimentary canals are un-
branched. Its life-history has not
yet been worked out. Probably it
is similar in most respects to that of
Fic. 28.—Distomum Distomum hepaticum.

eee Lije-History of Distomum Hepati-

cum.—Distomum hepaticum is subject
to an alteration of generations, involving a change
of hosts.

In the bile-ducts the adult parasite fertilizes itself, or
a cross-fertilization is brought about by the union of
two individuals. Asa result, in spring or early summer
the worm migrates towards the intestine, and deposits
its eggs either in the bile-ducts themselves or in the
intestine. In size these vary from 20 to 80 y. They
are oval in shape, and provided with an operculum,

PARASITES WHICH INVADE THE LIVER IOI

or lid. They consist of a germ cell and a number of
vitelline or yolk cells of granular consistence, destined
to provide food for the developing germ cell. These
pass out with the bile, and are expelled from the animal’s
body with the feces. For their further development
it is essential that they should fall upon or be carried
to damp or marshy ground, otherwise they undergo
desiccation and die.

Incubation takes place in from one to three months,
according to the weather and other conditions. Each
ovum hatches out into what is known as a Miracidium,
or ciliated embryo, from the cilia which surround it.
This organism is somewhat pear-shaped, and is provided
at its anterior extremity with a prominence—really a
boring apparatus.

It now swims freely in water till it finds a small
fresh-water snail known as Limnea trunculata. This
snail has a spiral grey shell, and is from 4 inch to $ inch
in diameter, and about the same from base to apex.
It is not found in Australia, although fluke disease
abounds in that country. Probably another inter-
mediate host is present there.

The ciliated embryo now attaches itself to the soft
parts of the body of the snail, and finally reaches the
lung. The organism then loses its cilia, becomes
shortened, and finally becomes encysted in the snail
as the sporocyst.

The sporocyst contains masses of germ cells, each
clump of which develops into an organism known as
the Redia. This, too, contains a number of germ cells,
and possessesa mouth and a blind tube representing
the intestine. It wanders to the liver of the snail,
where its germ cells develop into about twenty Cercarie,
which are nearest in structure to the adult parasite. The
body is made up of an egg-shaped, flat anterior portion,
and a tail posteriorly situated. The two suckers are

102 VETERINARY PARASITOLOGY

present as in the adult, and there is a simple alimentary
tract. The Cercaria passes out of the Redia, and after
a short period leaves the snail and swims about in
moisture. It next attaches itself to a blade of grass or
some other object, loses its tail, and secretes a covering
round itself, thus becoming encysted. It is swallowed
by an animal, and providing that this be one suitable
for its further development, it loses its leathery coat,
passes up the bile-ducts (or, according to some authori-
ties, the portal veins), and reaches the liver, where it
becomes adult.

Occasionally they may reach the lungs, where they
form cysts containing flukes floating in a brownish fluid.
Other parts of the body may be similarly invaded.

Occurrence and Symptoms.—Fluke disease occurs in
sheep and cattle kept on marshes or in damp surround-
ings suitable for the development of the snail which acts
as intermediate host. The embryos reach the liver
during the last few months of the year, and at first
cause few or no symptoms. The appetite remains un-
changed, but there may be a little falling off in condi-
tion and slight dulness. In other cases death may occur
from hepatitis, or from embryos, carried by the blood-
stream, being deposited in organs such as the heart or
brain. After a few weeks the sheep again regain condi-
tion, and for a short while appear to be putting on
flesh. In many parts of the country it is the practice
to run the sheep on fluky ground in order to fatten
them more quickly for the butcher. This flesh-forming
period is only of short duration, and the symptoms now
become more marked. The wool becomes dry and
loose in parts, emaciation sets in, and the appetite is
capricious, while great thirst is a constant feature.
Ascites, with cedema of the dewlap and’submaxillary
space, now appears, and the affected sheep show
dyspnoea and inability to travel fast. The subcu-

PARASITES WHICH INVADE THE LIVER 103

taneous tissue over the lumbar region and over the
rump becomes cedematous and flabby to the touch.
The eyes have a peculiar watery appearance, with
cedema of the lids. Symptoms of jaundice may be
apparent, arising from blocking of the bile-ducts. Ova
may be found in the feeces. Death is by no means un-
common at this period.

About the end of January the symptoms become
even more apparent, and appetite practically disappears.
(Edema may now be almost entirely localized to the
submaxillary space, and this is marked when the animal
is grazing, but almost entirely disappears after a journey.

Diarrhcea now sets in. Anzmia is extremely marked,
and the number of red corpuscles present in the blood
is enormously reduced. Ewes in lamb often abort about
this time.

Death may now greatly reduce the flock, but a number
of the strongest and best-conditioned animals survive,
and in these, about March or April, the parasites leave
the liver and pass out with the faeces.

In oxen the symptoms are similar, but are not usually
so severe. In these animals the disease may last for
years.

Post-mortem Lesions.—The chief changes are seen in
the liver itself, particularly in the bile-ducts. These
show chronic inflammatory changes in the form of
thickening of the walls, owing to the deposition of
fresh connective tissue. It is not uncommon to find
bile-ducts so distended as to reach } inch in thickness.
Those nearer the surface cause projection of the capsule
of the liver in the form of grey ridges, easily discernible
before the liver is cut. As a result the liver tissue
atrophies and becomes fatty. The bile-ducts contain a
quantity of dark-coloured bile, often gritty, and, on
squeezing, flukes may emerge. Adhesion of the visceral
and serous layers of the peritoneum is common, while

104 VETERINARY PARASITOLOGY

in the liver it is probable that the flukes live principally
on blood.

Ascites and emaciation may be visible on _post-
mortem examination, and there may be submaxillary
cedema or oedema of the dewlap.

Treaiment.—There is no treatment of much use, as no
anthelmintic has been discovered that will destroy
parasites within the bile-ducts.

The best course is to fatten sheep that are kept on
infected land as quickly as possible. Volatile oils have
been recommended.

The following is a favourite prescription :

BR Ferrisulph. .. 8 is oe Bie
Sodii chlorid. .. a a .. Bij.
Bacc. junip. .. ee i on 3X:
Pulv. gentian .. au oD ee) LDS
Oatmeal ‘ ad lb. xxv.
Half a pound of this mixture ‘should be fed to each sheep
once daily.

Prophylaxis.—This is of the greatest importance on
those lands in which the disease is prevalent.

The most effectual means of prevention consists in
draining all low, marshy fields, and afterwards dressing
with sulphate of iron, salt, or lime. From about 2 to
3 hundredweight per acre is necessary. From May
to September is the best time of the year in which to
dress the land.

Rock-salt should be provided for the sheep to lick.
In many parts of the country aromatic shrubs are added
to the food during autumn and winter. The commonest
are broom, willow, birch, and juniper.

Raised drinking-troughs are sometimes of assistance.

Care must be taken not to infect land not already
fluky. Dogs, hares, rabbits, and other animals, may
carry infection. In the dog, eggs may pass uninjured
from a piece of ingested liver out on to fresh pastures,

PARASITES WHICH INVADE THE LIVER 105

As previously stated, if it is impossible to keep sheep
on any other land than that infested with flukes, it is
the best course to fatten them off as quickly as possible.

Distomiasis in Other Animals.

The liver of the horse may occasionally be affected.
Distomum truncatum and Distomum albidum affect the
liver of the dog, and Distomum felineum affects the liver
of the cat in some countries, notably in Holland and
India. Distomum heterophyes affects dogs in Japan.
Monostomum hepaticum affects swine.

CHAPTER IV
PARASITES OF THE RESPIRATORY TRACT

NOSE.

CoccIpDI1A sometimes set up nasal catarrh in rabbits.

Linguatula Teenioides.—This is a degenerate member
of the Arachnida. As the name indicates, the body is
elongated, ringed, and worm-like. The anterior ex-
tremity is broad and rounded in shape, and scarcely
distinguishable from the thorax and abdomen. Legs
are absent, with the exception of vestiges in the form
of two hooks, which curve backwards at each side of
the mouth, and which can be protruded or retracted at
will through slit-like openings. The mouth is sur-
rounded by a ring of chitin.

The male is small, being usually under r inch in
length, and white in colour.

The female may measure 5 inches in length, and is
greyish or sometimes almost yellow. It is quite common
to find the parasite rolled up.

Lire-History.—The female deposits eggs in the
nasal cavities, from which they escape by the nasal
discharge. If they happen to fall on grass or fodder,
they may be ingested by another animal, and providing
that animal be one suitable for their further develop-
ment (ox, sheep, rabbit, sometimes a horse), on reaching
the stomach or intestine they hatch out into larve.
They bore through the intestinal wall into the liver or
mesenteric glands, and become encysted there. They

106

PARASITES OF THE RESPIRATORY TRACT 107

then moult and develop rings, each ring bearing a
number of short spines. At this stage the parasite is
spoken of as Linguatula denticulatum.

They remain encysted for about six months, and then
migrate into the peritoneal cavity, pleura, or intestine,
and escape into the open. Occasion-
ally they bore into a bronchus and
are coughed up.

Dogs may be infected by sniffing up
larve thus deposited on the ground,
or by ingesting rabbits, or portions of
viscera containing larve.

SymMPToMs, ETc.—The adult parasite
is found between the turbinated bones
or in the frontal sinus of dogs, or
occasionally of goats, sheep, or even
man.

The symptoms consist of unilateral
nasal discharge, sneezing, epistaxis,
dyspnoea, and coughing.

TREATMENT. — Injections of weak
creolin, lysol, or iodine solutions.

Inhalations of chloroform, carbolic
acid, turpentine, sulphur, iodine, for-
malin, etc.

Larve of Céstrus Ovis.—The fly
which represents the adult form of
this larva is from Io to 12 millimetres in
length, with a yellow head, a brownish-
grey thorax, and an abdomen mottled
with white, yellow, and black. The
wings are transparent, and show a terminal streak and
three spots. The fly is active from May to October. The
female lays her eggs in, or close to, the nostrils of a sheep.
Sheep, when attacked by the fly, rush wildly about, and
rub their noses against trees and fences until they bleed.

Fic. 29.—LinGua-
TULA TANIOIDES,

108 VETERINARY PARASITOLOGY

Instead of being oval, as in the case of the ova of
Céstrus equi, the ova of Gstrus ovis are kidney-shaped.
The larve have the body white, x inch in length, and
divided by dark transverse streaks. The dorsal surface
is rounded and convex from side to side, while the
ventral surface is flat, and on this surface each segment
after the third carries red pointed spines, laterally
situated, leaving a plain middle portion.

The larva spends about ten months within the nasal
cavities, after which it escapes and becomes a chrysalis.

This stage lasts six months, and the adult stage is then
attained.

Symptoms.—When a number are present in the nose,
frontal sinuses, or horn-cores, there may be unilateral
nasal discharge, purulent or blood-stained in many
cases, with repeated rubbing of the nose against other
objects. The head is carried a little to one side and
frequently shaken. Occasionally the symptoms resemble
those of gid. Epileptiform convulsions may occur, and
death may follow. Ova may also be present in the
larynx, trachea, or may reach the brain by passing
through the ethmoid bone.

TREATMENT. — Fumigation. Trephining the horn-
cores in some cases.

PREVENTION.—Where the fly is common it is best to
use special feeding-boxes, with apertures of sufficient
size to admit only the nose. Tar mixed with fish-oil is
smeared around the apertures, so that the nose is
constantly dressed with the mixture. This usually
suffices to keep the fly at a distance.

BRONCHIAL STRONGYLES.

These parasites inhabit the trachea and bronchi of
various animals. They have the caudal pouch sup-
ported by chitinous rings, but the mouth is non-
chitinous.

PARASITES OF THE RESPIRATORY TRACT 109

There are eight species :

I. Strongylus Filaria—Sheep, goat, deer, and camel.
Male, 3 to 8 centimetres; female, 5 to 10 centimetres.
White, thread-like, ovoviviparous.

2. Strongylus Rufescens.—Sheep and goat. Male,
2 to 3 centimetres; female, 3 to 4 centimetres.
Reddish-brown, ovoviviparous.

3. Strongylus Micrurus.—Calf. Male, 4 to 5 centi-
metres ; female, 6 to 8 centimetres. White and taper- -
ing, ovoviviparous.

4. Strongylus Pulmonalis.—Calf. Less common.

5. Strongylus Armfieldii—Male, 2 to 3 centimetres;
female, 4 to 5 centimetres. Thread-like, ovovivi-
parous.

6. Strongylus Paradoxus.—Pig. Male, 1-5 centimetres ;
female, 3 to 4 centimetres. White or brown, ovo-
viviparous.

7. Strongylus Pucillus.—Cat. Male, 5 millimetres;
female, 10 millimetres.

8. Strongylus Commutatus.—Wild rabbits and hares.

OcCURRENCE.—Verminous bronchitis, or, as it is more
popularly termed, “ husk,’’ or ‘“‘ hoose,” occurs chiefly
in sheep, lambs, and calves, though it is by no means
uncommon to find adult bovine animals affected. It
is of more frequent occurrence on low-lying damp
ground, and seldom attacks animals pastured on high
ground. A large number, usually an entire flock, are
attacked at one time. Autumn is particularly the time
of the year at which the disease is rampant, and in wet
seasons it attains its greatest prevalency.

Stall-fed calves are seldom affected, and then probably
through hay and fodder grown on infected land. It is
not certain by what means infection is brought about,
but it has been suggested that the parasites at some
period of their existence reach the stomach with the
food, and are then carried into the pharynx during

IIO VETERINARY PARASITOLOGY

rumination, and so pass down the trachea. Other
observers state that the embryos are carried to the
bronchi or lungs in the blood-stream.

SymptToms.—These vary considerably according to
the site and variety of the parasite present. For
instance, in sheep Strongylus filaria mainly produces
symptoms of bronchitis, while Sivongylus rufescens pro-
duces those of pneumonia.

In Bovines.—Strongylus micrurus of the calf produces
either bronchitis or pneumonia, according to whether
the worms are seated in the large bronchi or in the
smaller divisions deeper in the lung.

In simple cases, where the symptoms are those of
bronchitis, there is gradual wasting and emaciation,
with pitched coat and general signs of unthriftiness.

Cough is always present. In character it is frequent,
short, and harsh; the head is held down, and a quantity
of thick ropy saliva issues from the mouth. The dis-
charge from the nose may contain worms, eggs, or
embryos. The appetite is usually at first undisturbed.
As the disease progresses the cough becomes weak and
faint, and the animal gasps for breath.

In those cases in which the worms are situated in the
smaller divisions of the bronchi there are present
symptoms of pneumonia, more or less acute, with rapid
breathing, elevated temperature, and anorexia, In
some cases the symptoms are indistinguishable to the
naked eye from those of tuberculosis. In the former
type of the disease the degree of mortality is low, pro-
viding the animals are well nourished, but in the latter
type death is a very common sequel, and the degree of
mortality may be anywhere from 20 to 80 per cent.

Intestinal strongylosis often accompanies husk, as the
conditions necessary for the development of all these
parasitcs are identical.

Adult cattle usually show less serious symptoms.

PARASITES OF THE RESPIRATORY TRACT 111

Cough is present, but few of the signs observable in
young animals are noticeable.

In Sheep the symptoms are similar, but are more
serious than in calves. Lambs and yearlings are at-
tacked more often than older sheep.

In bad cases lambs feed on their knees, and death
takes place at a period varying from a week to two
months.

In Pigs——-Young pigs are chiefly affected, but the
symptoms are not usually serious, and disappear as
adult age is reached.

POST-MORTEM LeEsIons.—The appearances produced
by Strongyli are very varied.

1. Simple Verminous Bronchitis—In this type the
bronchial mucous membranes are infiltrated and swollen,
and often show extravasations of blood. The bronchi
contain viscous, often bloody, mucus, containing worms,
eggs, and embryos.

The lungs are usually emphysematous in parts and
cedematous in others. Bronchiectasis may often be
observed.

2. Verminous Broncho-Pneumonia.—This type of
lesion is the result of the passage of groups of worms into
the finer bronchioles. Hepatization takes place around
these areas. Localized pleurisy is not uncommon.

3. Pseudo-Tuberculous Verminous Bronchitis.—This
takes the form of nodules much resembling tubercles.
They produce an uneven surface, and are composed of
clusters of worms surrounded by connective tissue.

THERAPEUTICS.—Preventive treatment consists in
avoiding damp, low-lying ground, and in keeping young
cattle and sheep as far as possible on high ground.
Therapeutics may be classed under the following headings:

1. Fumigations—The agents usually employed are
chlorine gas (generated in an overhead receptacle),
sulphur fumes, carbolic acid, creosote, tar, etc.

112 VETERINARY PARASITOLOGY

Some practitioners use iodine. The process is as
follows: Two sacks are obtained; one is placed inside
the other, and both are immersed in a bucket of water,
thoroughly wetted, and wrung out. A brick made hot
in the fire is then dropped into the bottom of the sack,
and as much iodine as can be held on a threepenny-piece
is dropped on to it. The head of the calf is enveloped
in the sack, and held there till the animal has coughed
twice.

This method is highly recommended by those who
practise it, but, like all fumigation methods, it is open
to the objection that the worms, especially in the later
stages of the disease, often possess greater vitality than
do the calves themselves.

2. Tonics.—Preparations of iron, sodii chlorid., quassia,
or gentian, and aromatics, are useful to maintain strength
and condition in the early stages.

The following is useful :

BOL tereb. os ss #s .. Biij.
Asafeetide .. . ai .. Bj.
Chloroformi .. = eK .. Bvj.
Acid. carbol. .. a a .. Bij.
Aqua calcis .. is as .. Bvy.
Ol. lini. ee 3 .. O.j.ss.

M. Fiat mist. Sig.: One to two wineglassfuls to be given
twice daily in gruel to each calf, according to age.

This method is only applicable when the number of
animals affected is comparatively small.

3. Intratracheal Injection.—This is one of the best
methods of treatment. A very useful injection is as
follows :

BR Ol. tereb. Ns = ae .. 3.88.
Chloroformi |
Glycerini | os aa 3ss.
Acid. carbol. }
M. Fiat inj.

Dose.—Lambs, 3j.; calves, 5j. to 5iij.

PARASITES INHABITING SEROUS MEMBRANES 113

Many practitioners prefer olive-oil to glycerin. The
injection should be repeated in a week.

A modification is to trickle 1 drachm of the following
mixture down the nostrils :

Turpentine .. me tg +. 1 part
Ether .. a = ee -. 30 parts.

This method is not to be recommended.

PARASITES INHABITING SEROUS MEMBRANES.

Among these must be included the cystic forms of
several tapeworms already mentioned. Especially we
may mention :

1. Cysticercus Bailleti-—This is the cystic form of a
Bothriocephalus, and is found in the peritoneum, in
the pleura, or other serous membranes of the dog, cat,
and some other small animals. The cyst is formed of
an invaginated head without hooks, but having four
suckers, with an elongated body tapering at the posterior
end. The body is full of calcareous particles.

The whole length is from 1 centimetre to 2 centimetres.
The parasite is contained in the interior of a cyst, and
it is probable that it reaches the serous membranes
from the alimentary tract by means of the blood-stream,
as it is usually found in close proximity to bloodvessels.

2. Filaria Papillosa (Filaria Equina).—A white, thread-
like worm, tapering at each end. Male, 6 centimetres to
8 centimetres; female, 10 centimetres to I5 centi-
metres. Mouth bears eight papille. Tail spirally
twisted. Ovoviviparous.

This worm may be found within the scrotum of
horses during castration, especially in cases of hydrocele
and adhesions between the testis and scrotum, which
symptoms may be set up as a result of its presence. It
is commonest in India, but has been observed in Great

Britain.
8

114 VETERINARY PARASITOLOGY

It has also been found in the diaphragm, under the
dura mater, around the spinal cord, and in several other
situations, particularly as the embryo form in the eye
of Indian cattle.

3. Selerostomum pinguicola occurs in Australia and
America, in the fatty tissue surrounding the viscera,
more especially the kidneys.

The symptoms produced have been confused with
those of other diseases and greatly exaggerated.

4. Linguatula Denticulatum.—In the cat.

5. Filaria Cervina.—Peritoneum and eye of cattle.

6. Seclerostomum Armatum has been found within the
scrotum of horses and asses during castration.

HAEMATOZOA.

Sclerostomum Armatum Minor causes aneurisms
in the aorta or branches of the mesenteric arteries of
the horse. These may vary from the size of a pea to a
cocoanut. The aneurism usually has thickened walls,
and contains a thrombus, with a small passage through
which the blood still flows, together with a variable
number of worms, usually partially buried in the walls.

Bilharzia Crassa.—This parasite belongs to the Dis-
tomide. It affects cattle in Egypt, Arabia, India,
Mauritius, and the Cape.

The male and female are constantly joined together,
the female being contained in a gynzcophorous canal
running the whole length of the male, and formed by
the turning in of the edges of the latter.

The male is $ inch in length, and possesses an oral
and a buccal sucker. It is much thicker than the
female, which is 3 inch long and much more slender.

It chiefly inhabits the portal vein and the mesenteric
vessels, and is carried to the intestines. It is alsosome-
times found in the bladder, being carried there by the

PARASITES OF THE CIRCULATORY SYSTEM 115

blood-stream. The symptoms may hence be those of
enteritis or hematuria. Man may be affected with the
parasite obtained from cattle.

The means of infection in cattle is the drinking of
impure water.

Cystic forms of various tapeworms are sometimes
seen in the heart tissue (cf. Cysticercus cellulose,
Cysticercus bovis, Cysticercus tenuicollis, Echinococci).

The dog may be infested with several Hematozoa.

Hematozoon Lewisi.—This is the embryonic stage
of a Filaria, about zz inch in length. They may be
found in drops of blood taken from the capillaries of
dogs in India, China, and the East. They have a fine
body, drawn out into a very thin tail. According to
some observers (Grassi, Lewis), when observed micro-
scopically, they have the power of attaching themselves
by the buccal end to the cover-glass, and freely moving
the body. This is not evident in the next-mentioned
parasite.

Filaria Immitis.—This is a white filiform worm, with
the anterior end only slightly larger than the posterior,
both being somewhat blunt. The tail is spiral and
carries two wings. The average length is about 8 inches,
the females being the larger.

The parasites inhabit the right ventricle of the heart
(often twined round the chorde tendinez) and the
pulmonary artery of dogs in Denmark, Italy, China,
etc.

The embryos inhabit the peripheral vessels, particu-
larly at night, and the large vessels of the body by day.
They much resemble Haematozoa Lewist.

SympToms.—Often these are absent.

Usually the symptoms are those of chronic valvular
disease, with dyspnoea, cough, and dropsy. Embolism
of various vessels, such as those of one limb, is not
uncommon. Symptoms resembling those of rabies

116 VETERINARY PARASITOLOGY

have been recorded by several observers. The embryos
can usually be discovered in the blood.

In time the heart hypertrophies. Syncope, epistaxis,
and hematuria follow on.

Lire-History.—This is doubtful, and the inter-
mediate host has been supposed to be a Mollusc or
Crustacean.

Probably the embryos undergo development in the
bodies of mosquitoes, migrate back to the mouth, and
are thus transmitted ; or else the pools at which the
dogs drink are contaminated by mosquitoes alighting
at the edges.

The parasite may be present in pups born to an
infested bitch.

Strongylus Vasorum.—This is a smaller worm, a light
pink in colour. The male is $ inch in length, with a
bilobed caudal pouch.

The female is about 3 inch in length. Their habitat
is the right heart and pulmonary artery.

They set up endocarditis and thrombosis of the
pulmonary artery. .

Lafosse obtained good results by treating affected
dogs with turpentine.

Arsenic might be useful.

Spiroptera Sanguinolenta.—Although this worm is
usually an inhabitant of the first portion of the ali-
mentary tract, it is found in Italy and China encysted
in the wall of the aorta. The bronchial glands have
been found to contain Spiroptera in one or two in-
stances.

PARASITES OF MUSCLE AND CONNECTIVE
TISSUE.
Spiroptera Reticulata—This worm causes sub-
cutaneous tumours of a fibrous nature in muscular and
tendinous structures.

PARASITES OF MUSCLE 117

It is a filiform, spirally twisted worm, about 16 to
18 inches in length.

The tumours are from x inch to 2 inches in length,
and somewhat egg-shaped. They occur principally
in the neck and flexor tendons, particularly in the
suspensory ligaments of the fore-limbs, in which case
they set up chronic lameness.

Treatment is excision.

Sarcosporidiz.—These are Sporozoa, inhabiting mus-
cular tissue or connective tissue.

Balbiania Gigantea.—These Psorosperms may inhabit
the connective tissue of the sheep, and also of the pig,
ox, goat, and other animals. Their presence is mani-
fested by the appearance of small nodules, varying
from 2 millimetres up to I centimetre in diameter.
The commonest positions in which the nodules may
be met with are the cesophagus, bulb of the tongue
and pharynx, neck, abdominal muscles and connective
tissue, and the muscles of the thighs, especially the
adductors. Each nodule consists of a thin envelope,
containing a large number of sickle-shaped corpuscles
or rounded bodies.

Balbiania gigantea may produce epileptiform fits or
asphyxia from spasm of the larynx or cedema of the
pharynx.

They are of chief importance to the meat-inspector.

Sarcocystis Miescheri.—These parasites produce the
so-called ‘‘ Miescher’s tubes ”’ in the muscles of the pig.

In the flesh the parasites may be seen dotted about
in various parts, and they may be just visible to the
naked eye as small whitish, drawn-out specks, with the
dark-coloured flesh as a background.

When examined microscopically, the Sarcocyst is seen
to be composed of a somewhat thick striated envelope,
provided on the outside with numerous cilia, and con-
taining a number of fusiform, comma-shaped or rounded

118 VETERINARY PARASITOLOGY

spores, each of which shows one or two nuclei. These
spores are contained in cells formed by the crossing of
membranes, thus giving the interior of the Sarcocyst,
when magnified, the appearance of a honeycomb.

The symptoms produced in the pig are usually not
noticeable, but paraplegia, rash, and fever have been
observed.

It is doubtful whether man is infected by ingestion.

Sarcocystis Tenella.—In this the envelope is thinner,
but otherwise it is similar to Sarcocystis Mieschert. It is
especially found in the adductors of the thigh of the
sheep, and next frequently in the heart muscle, but any
portion of the muscular system may be affected.

MEASLES.

“Measles” is a term denoting the condition of the
flesh of various animals produced by the presence
therein of Cysticerci.

Cysticercus cellulose, for instance, is the cystic form
of Tenia solium of man, and inhabits the muscles of the
pig, dog, and cat.

Cysticercus bovis is the cystic form of Tenia saginata.
It inhabits the muscles of the ox.

>

Measles of Pork.

This condition arises from the presence of Cysficercus
cellulose. This is a small ovoid cyst, about 15 milli-
metres long and 73 millimetres wide. It shows, when
magnified, a white spot, corresponding to the invaginated
head. If the head is extruded by pressure, it may be
seen to be four-sided, and to carry four suckers and a
rostellum, bearing a double row of hooks, twenty-four
to thirty-two in number.

The Cysticerci may be found in any or all the striped
muscles, but the muscles chiefly affected are, in order:

PARASITES OF MUSCLE 119

the tongue, cervical muscles, muscles of the shoulder,
pillars of the diaphragm, intercostal muscles, psoas
muscles, muscles of the thigh. The myocardium is also
frequently affected, as are also various organs of the
body.

The muscles containing the Cysticerci are flabby and
pale in colour, and contain small cavities, which lodge
the parasites. On section, the flesh is wet, and, if badly
affected, a yellowish clear fluid may exude. In pork
that has been measly for a considerable length of time
the Cysticerci become calcified.

Symptoms.—Usually symptoms are not recognizable
during life. When very advanced, there may be diffi-
culty in muzzling, loss of energy, anorexia, diarrhoea,
stomatitis, and death.

The Cysticercus cellulose of the pig, when ingested by
man, develops in the intestine into Tenia solium. The
worm becomes mature about two months later.

The flesh, when eaten, is gritty and sweet to the taste.
Roasting at 120° F. for one minute kills the parasite, but
this temperature is not usually reached in the centre of
pork while being cooked for the table, though the ex-
ternal temperature may be 212° F.

In smoked hams and pickled pork the vitality of the
Cysticerci is usually weakened.

Measles of Beef.

This condition is produced by the presence of Cystz-
cercus bovis in the muscles of the ox.

This is an ovoid cyst, measuring from 3 to 15 milli-
metres in length. It shows a small, dense, yellowish
area at one point, corresponding to the invaginated
head. When extruded, the head presents the characters
of that of Tenia saginata of man, tetragonal in shape,
devoid of hooks, and possessing four large rounded
suckers.

120 VETERINARY PARASITOLOGY

These Cysticerci may be found in any organ, but
voluntary muscles are usually affected.

The most common site is in the muscles of mastication
—the masseter, pterygoids, and in the tongue.. Then, in
order, follow the heart, gluteal, intercostal, cervical,
psoas, and pectoral muscles.

The Cysticerct bovis are never present in such numbers
as are the Cysticerct cellulose, and, moreover, they
quickly become calcified.

Symptoms.—Usually nil.

When ingested by man, the Cysticercus develops into
Tenia saginata in the intestine.

TRICHINOSIS.

This is the name applied to the condition arising from
the presence of Trichina spiralis in the body of the pig
or man.

Trichina spivalis is a member of the family Tricho-
trachelide. :

The adult male worm is about 1 to 5 millimetres in
length, and the female 3 to 4 millimetres. They possess
very slender bodies, tapering at each end, with no trans-
verse striation. The female is ovoviviparous.

LirE-History.—The adult stage is passed in the intes-
tine and the larval stage in the muscles.

When flesh infested with encysted larve has been
ingested by a suitable animal, more especially the pig,
or even man, the cysts become partially digested and
the larve are set free. After an interval of a few days,
they develop into sexually mature Trichine, copulate,
and the females soon deposit embryos. The number
produced by a single female at one ovulation may exceed
10,000. The embryos then proceed to migrate to the
muscles, either by boring through the intestinal wall or
by the aid of the blood or lymph streams. The average

PARASITES OF MUSCLE 121

interval between ingestion of trichinous meat and muscle
infestation is ten days. On arriving at its destination,
each larva coils itself into a spiral, and by its presence
irritates the tissues, so that eventually fresh connective
tissue is thrown out from that already between the
bundles of muscle fibres, and a cyst wall is formed around
the parasite.

Each cyst is somewhat ovoid and pointed at the
extremities, and in its length lies parallel with the direc-
tion of the muscle fibres. The length of the cyst is from
0-3 to o-8 millimetre.

The commonest seats of infestation are :

Pillars of diaphragm.

Muscles of tongue and larynx.
Shoulder.

Intercostals.

Psoas muscles.

Adductors of thigh.

DAR Y NH

The muscles are infested to a greater extent close to
their insertions.

In order to discover Trichina cysts in pork, thin strips
are cut from the pillars of the diaphragm, tongue, etc.,
in the direction of the muscle fibres. These should be
macerated in a mixture composed of pot. chlor., 1 part,
and acid. nitric. dil., 4 parts. The strips are then shaken
in water, placed between two slides, and examined micro-
scopically. The coiled-up larva is then easily visible.

When trichinosis has been present for a long time
calcareous or fatty degeneration sets in, and in the
former case the cyst becomes hard, and gives a gritty feel
to the meat. Pigment may also be deposited in the cyst.
Calcareous and fatty deposits usually render the parasite
harmless.

Symptoms.—In the pig symptoms are usually absent.
If the number of invading Trichine is large, the first

122 VETERINARY PARASITOLOGY

symptoms noticeable are those of enteritis. There may
be anorexia, fever, thirst, grinding of the teeth, with
tucked-up flanks and arching of the back. Chronic
diarrhcea then sets in. About the tenth day these
symptoms diminish and give way to muscular symptoms.
The animal is stiff and has difficulty in walking. The
muscles are sore to touch, and the pig usually remains
in the recumbent position. The animal may now re-
cover or become dropsical and eventually die.

INFECTION, ETC.—Infection takes place in the pig
from ingestion of trichinosed flesh, such as that of rats,
which are frequently affected, or from devouring the
excreta of animals containing Trichina in some stage of
their life-history. Probably the pigs infect the rats, and
vice versa, and so the existence of the disease is main-
tained. In Germany, America, Holland, Denmark, and
Sweden, and particularly in Russia, trichinosis in man
is not rare, owing to the practice of eating only partially
cooked pork.

VitaLity.—Boiling affected pork for fifteen minutes
per pound weight is considered safe, and experiment has
shown the Trichina to be destroyed by this means.

Roasting, if complete, is sufficient to destroy the
parasites.

Salting and smoking are not reliable.

Putrefaction has little influence on their vitality, and
after four months some Trichine may yet be alive.

PARASITES AFFECTING THE EYE.

Numerous parasites may affect the eyelids. Among
these are Acari, Demodectes, and the Pediculide.

Besides these, various Diptera attack theexterior of the
eye, especially the nasal canthus.

Filaria Pellucida.—There is some doubt as to whether
this worm may not be an undeveloped stage of Filaria

PARASITES AFFECTING THE EYE 123

papillosa. It is commonest in the horse, and is met
with in India, Burma, and Ceylon.

It is a fine thread-like, reddish-white worm, somewhat
thicker in front. The male is about 30 millimetres in
length, and the female is slightly smaller.

The habitat of this parasite is the anterior chamber
of the eye. Both eyes are seldom affected simultane-
ously, and there is usually only one worm present, but
three is not an uncommon number.

Symptoms.—Conjunctivitis and swelling of the eye-
lids are present, arising from irritation. Photophobia
is very marked. In the early stages the worm may
sometimes be seen through the cornea. Later opacity
sets in. ‘‘ Loin-weakness”’ has been associated in India
with the presence of the Filariain the eye.

TREATMENT.—Cocaine is applied, and the cornea
punctured with a cataract needle. The worm is thus
brought into the wound by the rush of aqueous humour,
and is withdrawn. A larval form of Filaria cervina
infests the eye of the ox in a similar manner.

Similar parasites have been observed in sheep, dogs,
and poultry.

Filaria Palpebralis—A white filiform worm, from
8 to 16 millimetres in length.

It has been found in the lachrymal sac and in the
conjunctiva beneath the eyelid.

Filaria Lachrymalis.—This is a longer worm, Io to 24
millimetres in length. It affects the eyelids of cattle in
the South of France in a similar manner.

TREATMENT.—This consists in removing the parasites,
and applying mild astringents and sedatives to lessen
the conjunctivitis.

APPENDIX I

In advanced cases of the pustular type we have lately
obtained almost remarkable results from the following
treatment :

The largest pustules are first squeezed out and the
affected areas dressed once or twice, at intervals of a
day, with the following mixture :

B Formalin a4 a a Bs dilj.
Glycerin : a3 ae a2 5.
Spts. vini rect. £4 oe .. Bij.

Ol. caryoph. .. ae oe .. Biij.
Ol. rapii a 2% #5 .. ad 3vj.

M. Fiat. lin.

This application at first produces marked hyperemia
and swelling of the skin.

After one or two dressings the pustules appear flat-
tened, dry, and scaly, and the majority soon disappear,
leaving the skin smooth and apparently healthy. The
parts are then dressed with Ung. sulph. co. until they
are thoroughly softened, and then treated daily with
the following :

R Formalin $4 fi are .. §8s.
Glycerin ees ae .. Bh
Tinct. cantharid. es ae .. 3iss.
Acid. salicylic. aa 2% .. 58s.
Spts. vini rect. att Ba doe, SOs
Ol. ricini ha os es .. Bij.

Ol. rapii Ma af os -. ad 3vj.

M. Fiat. mist.
124

APPENDIX 125

The hair soon commences to grow, and in the great
majority of cases thus treated by us a perfect cure has
resulted, although many have at first appeared hopeless.

APPENDIX II

By the Sheep Scab Order of 1910, recently issued,
Article 5 of the Sheep Scab Order of 1905 is revoked,
and an article substituted which enacts that for the
prevention of scab an inspector of the Local Authority
shall serve an Isolation Notice on the owner or person
in charge of sheep recently affected or in any way
suspected of scab or exposed to infection, and that such
sheep shall not be permitted to stray or come into con-
tact with other sheep until a further notice has been
issued. It further enacts that if, on veterinary inquiry,
the above suspicions are found to be correct, the sheep
shall be efficiently dipped by the owner, and, if requred,
in the presence of the inspector.

By an amendment of Article 9, a Local Authority
may make regulations requiring the dipping of sheep
moved from another district into their district (providing
they remain there over seven days), and may also issue
notices regulating their movements, and requiring an
owner to notify the arrival of sheep.

Paragraph 4 of Article 30 is omitted, and a notice
substituted forbidding the straying of sheep, in con-
travention to the order, under penalty.

IN

ACANTHOCEPHATLA, 56
Acariasis, psoric, 8
non-psoric, 33
Acarina, 8
Achorion, 2, 3
quinckeanum, 6
Amblyomma Hebreum, 36
Amiphistomum Collinsi, 71
conicum, 72
tuberculatum, 79
Ankylostomum trigonocepha-
lum, 95
Annelida, 50
Aphaniptera 43
Aptera, 37
Ascaridee, 54
Ascaris marginata, 94
megalocephala, 60, 62
muystax, 95
ovis, 82
suis, 84
vitulorum, 72
Autumnal breeze-fly, 45

Balbiania gigantea, 117
Bilharzia crassa, 53, I14
Boophilus, 33
Bothriocephalus latus, 91, 86

cordatus, 86

felis, 93

fuscus, 86
Bots, 57
Brachycera, 43, 44
Breeze-flies, 44
Bronchial strongyles, 108
Bronchitis, verminous, IIT
Broncho-pneumonia, vermin-

ous, III
pseudo tuberculous, 111

DEX

Cestodes, 52
Chorioptes, 9
Coccidia, 79, 106
in the liver, 97
Coccidium Zurni, 80
oviforme, 80
cuniculi, 98
Ccenurus cerebralis, 91
Culicide, 43
Cutaneous filariasis, 41
Cysticercus Bailleti, 113
cellulose, 115
fasciolaris, 93
pisiformis, $8, 98
tenuicollis, 88

Demodecide, 9, 21
Demodectic mange, 21
Demodex folliculorum, II, 21
Diptera, 43
Dipylidium caninum, 86, 91
Distomata, 53
Distomum hepaticum, 99
albidum, 105
felineum, 105
heterophyes, 105
lanceolatum, gg, 100
truncatum, 105
Dracontiasis, 42

Echinococcus cyst, 87
veterinorum, go, 98
Echinorhyncus gigas, 56, 83

Eustrongylines, 5

Fascioliasis, 99

Favus in sucklings, 5
in dog and cat, 6
multipapillosa, 41

126

INDEX 127

Filaria cervina, 114
equina, 113
heemorrhagica, 41
immitis, 115
irritans, 42
lachrymalis, 123
Medinensis, 42
palpebralis, 123
papillosa, 113
pellucida, 122

Filariidee, 54, 55, 57

Fluke disease, 99

Follicular mange in the dog,

2
in the pig, 24
‘“‘Formication,”’ 23

Ganglyonema scutatum, 60,
72, 83

Gastrodiscus, 53, 71
Hi gyptiacus, 71
polymastos, 71
Sonsinoi, 71

Gastrophilus equi, 57
heemorrhoidalis, 58
nasalis, 59
pecorum, 55

Glossina morsitans, 45

Hemaphysalis Leechi, 36
punctata, 36
Heematobia, 45
Hematopinus, 37
eurysternus, 38
macrocephalus, 38
pedalis, 38
piliferus, 38
tenuirostris, 38
urius, 38, 39
vituli, 38
Heematopota, 45
pluvialis, 45
Heematozoon Lewisi, 115
Hemopis sanguisuga, 50
Helminthes, 50
Hippobosca aa 48
rubipes, 4
Hippoboscide, 43, 44, 45, 48
Hirudo medicinalis, 51
Hypoderma bovis, 46
equi, 47

Intestine, protozoa inhabiting
the, 79
Ixodes, 33, 34
plumbus, 36
reduvius, 36
ricinus, 36
Ixodide, 33

Leptus autumnalis, 36
Limnea trunculata, IoI
Lingulatula denticulatum, 97,
107, 114
teenioides, 97, 106
Liver rot, 98
“ Lousiness,”’ 37
Tucilia, 45
Ceesar, 49
macellaria, 49
sericata, 49

Mange, 8
follicular, 21
in the cat, 19
in the dog, 18
sarcoptic, in the pig, 26
symbiotic, in dogs and
cats, 20
Mange in cattle, 17
psoroptic, 17
sarcoptic, 17
symbiotic, 17
Mange in sheep, 26
psoroptic, 27
sarcoptic, 26
symbiotic, 32
Mange in the horse, 12
psoroptic, 14
sarcoptic, I2
symbiotic, I5
Measles, 118
of beef, 119
of pork, 118
Melophagus ovinus, 49
Mesocestoides lineatus, 86, 92,
93
Microsporon, 2, 3, 4, 6
Miescher’s tubes, 117
Monostomum hepaticum, 105
Muscide, 44, 45, 49

128 VETERINARY PARASITOLOGY

Nemathelminthes, 52, 53
Nematodes, 52, 54
Nematoidea, 54
Nemocera, 43
Non-psoric acariasis, 33
Nose, parasites of, 107

Cesophagostomes, 75 ,
Csophagostomum Columbia-
num, 75
inflatum, 75
CGistridze, 44, 45, 46
Cistrus equi, 57
Estrus ovis, 48, 107,
Ollulanus tricuspis, 85
Odspora canina, 6
Ox breeze-fly, 45
Oxyuridee, 54, 55
Oxyuris curvula, 70
mastigodes, 70

Parasites, vegetable, 1
Parasitic granular dermatitis,

42
Pediculide, 37, 122
Pediculine, 37, 122
Phthiriasis, 30, 37
Platodes, 52
Platyhelminthes, 52
Protozoa inhabiting intestine,

79,85
Psoric acariasis, 8
Psoroptes equi, 14
Psoroptic mange in horses, 14

in cattle, 17

in sheep, 27
Pulicide, 40
Pupipara, 42, 48

Rain-rot, 29
Rhipicephalus, 33
annulatus, 36
appendiculatus, 36
Australis, 36
bovis, 36
bursa, 36
Ricinidze, 37
Ringworm, I
in the dog and cat, 6
in the horse, 4
in the ox, 6

Sarcocystis Miescheri, 118
tenella, 118
Sarcophaga magnifica, 49
Sarcoptes, 9
Symbiotes, 9, 10
equi, 12
minor, 19
ovis, 26
squamiferus, 18
suis, 26 .
Sarcoptic mange in cattle, 17
in the cat, 19
in the dog, 18
in the horse, 12
in the sheep, 26
Sarcoptide, 8
Sarcosporidiz, 117, 118
Sclerostomum armatum, 64,
II4
armatum minor, 66, 114
hypostomum, 82
tetracanthum, 64, 66
Sclerostomines, 56
Sclerostomum, pinguicola, 114
Serous membranes, parasites
of, 113
Sheep scab, 27
Simuliide, 43
Spiroptera, 57
megastoma, 57
microstoma, 57
reticulata, 116
sanguinolenta, 85
Stomoxys calcitrans, 45
Strongyles, bronchial, 108, 116
Strongylide, 54, 56
Strongylines, 56
Strongylus axei, 57
cervicornis, 75, 76
contortus, 72, 75, 76
convolutus, 72, 76
filicollis, 75, 76
gracilis, 72, 75, 77
MacFadyensis, 75, 76
ventricosus, 74
Strongylus filaria, ro9, 110
Armfieldii, 109
commutatus, 10g
micrurus, 109, ITo
paradoxus, 109
pucillus, 109

INDEX

Strongylus pulmonalis, 109
rufescens, Icg, I10
vasorum, I16

Sucklings, favus in, 5

‘« Summer sores,’’ 42

Symbiotes auricularis, 20, 32
bovis, 17

Symbiotic mange in cattle, 17

in dogs and cats, 20
in the horse, 15

Tabanidee, 43, 44

Teenia alba, 73, SI
ccenurus,
crassicollis, 93
cucumerina, 52, 91
cysts in the liver, 98
denticulata, 81
echinococcus, 86, 89
elliptica, 93
expansa, 73, 81
fimbriata, 81
Krabbei, 86, 91
litterata, 52
mamiillana, 60, 61
marginata, 52, 86, 88
perfoliata, 60
planissima, 73, 74
plicata, 60, 61
saginata, 119
serialis, 86, 90
serrata, 86, 87, 88
solium, IIg

Teenioide, 52

THE

129

Tapewornis in sheep, 81
Thysanosomum actinioides, 81
Ticks, 33
Trematodes, 52, 53

in the liver, 97

of the horse, 71
Trichina, 55

spiralis, 120
Trichinosis, 120
Trich: cephalus, 55

affinis, 79

crenatus, 85

Trichodectes, 37

latus, 38
pilosus, 38
pubescens, 38
scalaris, 38, 39
sphzerocephalus, 38
subrostratus, 38
Trichophyton, 2, 4, 6
mentagrophytes, 4
tonsurans, 4
Trichotrachelide, 54, 55
Trombidiide, 33
Trombidium holosericeum, 36
Tsé-tsé fly, 45

Vermes, 50
Verminous bronchitis, 117
broncho-pneumonia, III
pseudo-tubercular, 111

Worm aneurism, 65, 114
Worm colic, 67

END

Bailliére, Tindall anu Cox, 8, Henrietta Street, Covent Garden

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