UMASS/AMHERST

312DbbDDSSmSlb

rjf

'

'••-»?£*^p

.

:/'.

I

ft

SF

S?v

9Se

tHi

LIBRARY

OF THE

MASSACHUSETTS

AGRICULTURAL

COLLEGE

80UHCEX9A\TL__fc-_^J2>-^?55*r

SF
959

S7W5

DATE DUE

Digitized by the Internet Archive

in 2010 with funding from

Boston Library Consortium Member Libraries

http://www.archive.org/details/strongylusarmatuOOwinc

W7 *.■

Strongylus Armatus.

By J. F. Winchester, D.V.8., Lawrence, Mass.

/?;

(A paper read before the United States Veterinary Medical Association).

In presenting this subject to you, I do not want to con-
vey the idea that it is a new subject, or of recent origin. 1
simply desire that it may renew its youth, and to establish
the fact that this condition does exist in localities other than
on the continent. Judging from the literature in English on
this subject, it has certainly been overlooked, for, with a few
exceptions, only cases are reported that are interesting on
account of their grossness.

Owing to these facts, it has been necessary for me to ob-
tain the greater part of the literature from continental authors.
Finding that to be the case, I have had the able assistance of
Dr. J. M. Parker, of Haverhill, in order that a part of the
investigation may be original work. To him we are indebted
for several original drawings, the enlarged plates from Neu-
mann, mounted specimens, revised description of the parasite,
besides several post-mortem reports of horses that had lesions
due to this nematode.

At this point it might be well to state that in man, accord-
ing to Prof. W. F. Whitney, of Harvard Medical School,
aneurisms have never been found due to a nematode.

Strongylus Armatus.

Synonyms. — Armed Sclerostome ; Sclerostoma equinum ;
Palissade worm ; armed Strongyle.

This parasite is a nematoid of the genera strongylus. The
term " nematode " derives its origin from the Greek word
" nema," signifying " a thread ; " the term strongylus mean-
ing round or cylindrical.

History.

A knowledge of these parasites goes back to the seven-
teenth century. In 1655, Ruysch discovered in an aneurism
of the mesenteric artery of a horse an innumerable quantity
of small worms, and later he published three or four similar
observations. Schultze, in 1725, Chabert, in 1782, recorded
similar instances, and since then such observations have been
greatly multiplied, principally by Rudolphi, Hodgson, Greve,
Rigot and many others, including English and American vet-
erinarians. Bollinger has made an attentive study of this
parasitism, and in following it out has definitely established
its essential points. These verminous aneurisms have only
been found in the equidse, and, according to Neumann, more
frequent in the ass than in the horse.

Hering asserted that, except in young foals, it is rare to
find a horse without aneurismal dilation, and Bollinger esti-
mated that from ninety to ninety-four per cent, of adult
horses were so affected. They are found principally in the
large mesenteric artery and its branches, although it is found
in other arteries.

Description of Parasite.

Armed Sclerostome. — Body gray or brown, shaded with
red ; straight, rigid, the anterior part being broader than that
which immediately follows (see Plate 1). Mouth orbicular,
widely open, and rendered tense by several chitinous, con-
centric rings, the innermost of which are garnished with fine
teeth, while the outermost carry six papillas symmetrically
divided. On the outermost ring there is, also, a fringe of
what appeared like long, slender, sharp-pointed cilia ; these
are not seen when the mouth is closed ; they are best shown
by pressing on the cover glass, and so pressing the air out of
the mouth, causing the cilia to spread outward. The six pa-
pillae mentioned by Neumann are sharp spicules, and are
curved inward, hook-like, and probably serve the purpose of
attaching the worm to the mucous membrane. The buccal
capsule is sustained by a dorsal longitudinal line or rib, and
has at the bottom two round, sharp plates. Opening out of

the mouth is the pharyngeal capsule, which is armed ante-
riorly, and is funnel shaped, the posterior opening being the
smaller. The anterior portion of the oesophagus is constrict-
ed and narrow for about a third of its length, when it begins
to expand, forming the posterior ventricle or bulb.

The caudal pouch of the male is almost trilobate, the pos-
terior ribs being trifurcated, the middle double, and the an-
terior cleft. From the anterior portion of the pouch, the
spicula or male genital organ projects. It is first divided
into two equal parts — deferens canals — which afterward unite
toward the extremity.

The female, which is much thicker and larger than the
male, has the tail obtuse, and the vulva situated in the poste-
rior moiety of the body; and is surrounded by a roughened
circular surface of a reddish brown color, which is grasped
by the caudal pouch of the male during copulation. The
uterus occupies a large part of the body ; it can be made out
very readily by the ova, which are usually present in large
numbers.

The eggs are ovoid, and measure 92/* and 54M broad. The
dimensions are variable; sometimes the males are 18 mm. to
20 mm. long, and the females 20 mm. to 26 mm., and at other
times it is respectively 26 mm. to 35 mm. and 35 mm. to 55
mm.

The worms are found in an agamous or undeveloped
state in blood vessels (Plate II.). In this condition they are
covered by a thin, transparent membrane, which entirely
covers and closes the still undeveloped worm. It has a tem-
porary mouth and oesophagus, which lead directly into the
still imperfectly formed mouth. This worm infests the cse-
cum and commencement of the large colon, and, with the as-
caris megacephala, is the worm most commonly found in the
equidas.

The armed sclerostome holds firmly by the buccal arma-
ture to the mucous membrane, which forms at the point of
adherence a small, dark prominence. They are frequently
met with in couples, the two individuals forming an almost
right angle, and adhering so intimately that they may be pre-

served in this condition in alcohol. Notwithstanding their
sometimes considerable numbers, and the irritation they
should produce in the mucous membrane, their presence in
the horse is rarely betrayed by any appreciable symptom.
They have sometimes been accused of causing- death by ange-
mia, diarrhoea, colic, etc.

It is not only on the internal surface of the large intestines
that they are met with, for they are found in aneurisms of
the mesenteric artery, and in the hepatic, renal, spermatic,
occipital and other arteries ; in the muscles, pancreas (Gou-
baux, Montane) ligaments of the liver, and in submucous
cysts of the caecum, and sometimes of the duodenum. In all
these instances they are in an agamous state, and represent
one of the phases in the development of the species.

With regard to the intestinal tumors, their volume varies
from that of the head of a pin to that of a hazel or small al-
mond-nut, according to the development attained by the
worm inside each tumor. The latter also contains altered
blood or pus, and there is more or less hyperemia around
the circumference. The worm within is rolled upon itself,
and is, of course, of variable dimensions, sometimes extremely
fine, and never so large as in the adult state ; it is always des-
titute of reproductive organs.

Occasionally there is no worm in the tumor, and then there
is seen a small opening at the summit, by which it has escaped.
The worms found in the organs mentioned above are also
agamous ; they represent the primary phase of development,
as they do not become sexualized except in the caecum and
colon.

Colin states that the armed sclerostomes are worms which
migrate internally, and that their development is effected
almost in one place. The ova are deposited in the substance
of the intestinal mucous membrane — perhaps in the punctures
produced by the mouth of the female, or perhaps merely in
the orifices of the glands — and they are hatched there, the
embryos becoming encysted at the points where they are
hatched, in the cyst developed by their presence.

After being developed and having undergone several

moultings, they make their exit from the cyst, and fix them-
selves on the surface of the mucous membrane ; though a
certain number remain in their cyst, grow there, have the
genital organs partly formed, but nevetheless always remain
agamous. Those found in aneurisms and in the peri-intestinal
organs, must have entered the blood vessels on their leaving
the cyst, and in this way be carried — by a centrifugal migra-
tion— to the parts where they are found.

Railliet has shown that this is not the ordinary mode of
reproduction and development of the sclerostomes. The ova
are expelled along with the fseces, and become hatched in a
few days if they are in a damp place. The embryos that
issue from them are cylindroid, a third or a fourth of a milli-
metre long, somewhat obtuse in front, and have a filiform tail.
If the conditions of humidity continue to be favorable, they
gradually grow, their integument becomes folded and forms
a kind of sheath in which the worm moults in an evident
manner. Railliet has been able to keep them several months
in this state, or after complete moulting. It is at this period
that they enter the body of the horse, in the water the ani-
mal drinks (or perhaps on green forage), undergo moulting
if they have not already done so, and penetrate the substance
of the mucous membrane. Leuckart asserts that the embryos
should pass through an intermediate host before entering the
intestine of the horse. But however this may be, it is possi-
ble that after they have lodged themselves in the mucous
membrane, a small number of embryos stay to fix themselves
in the cysts which they cause to be formed. The majority
reach the circulatory system, and install themselves in the
abdominal arteries— principally at the origin of the great
mesenteric ; there they form aneurismal dilations, filled with
a ragged clot that adheres to the inner surface of the vessel,
and in this helminths are located.

After an indefinite sojourn in the aneurism, the worms
leave it by allowing themselves to be carried by the blood,
and in the course of time reach the caecum, where they form
the majority, if not the whole, of the submucous cysts.
Their last migration is, therefore, in reality, centripetal.

Finally, after remaining a more or less considerable time
in the tumor they had caused the formation of, and having
grown, the sclerostomes forsake it, attach themselves to the
mucous membrane, become sexualized, and copulate.

An interesting observation of Railliet gives support to this
theory as to the development, of the sclerostomes. He found
in a horse a considerable quantity of these worms in the
caecum, verminous cysts in the walls of that viscus, and a
smaller number in the duodenum and other parts of the small
intestine.

The cysts in the duodenum — which are rare — were grouped
on the small curvature of the intestine, and some were even
observed disseminated in the mesentery. All of the latter
contained sclerostomes still agamous ; but several of those in
the small intestines, like those oi the caecum, had an opening
in their center and were vacant, the helminths having left
them. This would seem to prove that the worms had reached
the intestines by way of the arteries.

These verminous aneurisms have only been seen in the
equidae — horse, ass, mule and hemione.

According to Semmer, at Dorpat all the foals, without
exception, have verminous aneurisms. Mather has witnessed
a kind of epizooty break out among foals, consisting of ver-
minous aneurisms of the aorta, near the origin of the renal
arteries.

These aneurisms are seen only on certain visceral branches
of the posterior aorta, and exceptionally on the posterior
aorta itself. In sixty-five horses, Hering has noted aneurism
of the trunk of the great mesenteric artery in seven cases ;
the cceliac artery in fifty-nine cases ; the cascal artery in
eighteen cases ; the artery of the small intestine in sixteen
cases ; the small mesenteric artery in two cases ; the cceliac
trunk in two cases ; the hepatic artery in three cases ; and in
the renal artery in one case. It is not uncommon to find more
than one aneurism in the same horse.

In thirty-five horses, Bollinger counted sixty aneurisms ;
and in adding these to one hundred and eight seen by Hering
in sixty-five horses, he reckoned that in one hundred horses

there were one hundred and sixty-eight aneurisms, of which
one hundred and fifty-three were in the large mesenteric
artery and its branches, four in the cceliac trunk, three in the
hepatic artery, three in the small mesenteric artery, three in
the renal arteries, and two in the posterior aorta. In one
hundred horses, ninety to ninety-four had one or more ver-
minous aneurisms. Sclerostomes were also several times
found in the spermatic artery, and on three occasions in the
cerebral arteries. Lastly, Roll indicates them as being found
in the vena cava, and, according to Valentine, a specimen
was discovered in the vena portse, at the Berne Veterinary
school.

The young form of the armed sclerostome — the aneuris-
mal sclerostome — is found in various arteries in the horse,
and those of the brain are not exempt. Three observations
have been published.

Albrecht reports the case of a horse which, during work,
suddenly began to stagger ; the eyes were fixed, and the res-
piration was noisy ; there were remissions and relapses. Three
hours after the first symptoms appeared, the head was carried
low and inclined to the left, and there were convulsive
movements of the neck and limbs. Soon it fell on the left
side, became unconscious, and manifested complete insensi-
bility. In this state it was killed, and at the autopsy there
were found diffuse meningitis, hemorrhagic encephalitis, and
in the middle lobe of the cerebellum a sclerostome, which
had probably arrived there when an embryo. Van Heillsaw
a three-year-old horse which was suddenly attacked with furi-
ous vertigo, that lasted about a quarter of an hour. An
autopsy revealed congestion of the brain and choroid plexus,
while a free sclerostome was lodged in the cortical substance
of the right hemisphere. Le Bihan found another worm of
this kind in the occipital artery ; rupture of the aneurism
caused the death of the horse in less than ten minutes.

Abildgaard discovered the filaria equina between the dura-
mater and the cranial arachnoid of a horse.

The agamous form of this worm has been encountered
more frequently in the spermatic than in the renal arteries of

the horse. Gurlt had already noticed the presence of these
worms in the vaginal sheath. Aitken once saw an armed
sclerostome in the spermatic artery of a foal, and Baird found
one in the testicle of a horse. Clancy met with thirteen on
the surface of the testicle of a three-year-old horse ; the gland
was indurated, and the envelopes infiltrated. Brodie pub-
lished a similar case. At the London Veterinary College one
worm was found in the spermatic artery of the ass, and
another in a funiculitis consecutive to castration.

It is remarkable the frequency with which these worms
occur in the abnormal testicles of horses affected with abdomi-
nal cryptorchidism. We met with a case of this kind in May,
1883, and Simonin and Jacoulet encountered three in the space
of two months, the testicles having undergone fibrous degen-
eration. On incising the testicle of a cryptorchid which was
normal in structure, Degive met with an armed sclerostome.
It would be interesting to ascertain the relation in frequency
between cryptorchidism and testicular parasitism. What is
certain, is that the concealed testicles of horses affected with
abdominal cryptorchidism often exhibit such alterations as
fibrous tumors or serous cysts.

In stallions affected with hydrocele, Schmidt and Pottinger
have remarked one or two specimens of this worm in the vag-
inal sheath. Their presence is easily explained by the com-
munication that exists between the abdominal cavity and that
sheath.

Pathological Anatomy. — The verminous aneurism is usually-
fusiform, sometimes globular or cylindroid. Its average size
is about that of a walnut, though it may not exceed that of a
pea, or it ma)' attain the dimensions of a man's head.

It consists of a dilation of the affected artery, with hyper-
trophy of its walls. The dilation is sometimes absent, not-
withstanding grave thrombic lesions in the vessel. (Durieux.)

The external tunic is usually thickened, and variably in-
durated, according to the age of the tumor. It adheres firmly
to the neighboring parts, and is more or less confounded with
the connective tissue.

The middle tunic is always hypertrophied, and sometimes

9

very much so. Its thickness — which is ordinarily about a
millimetre — may attain, and even exceed, two centimetres.
At one time this thickening is due to simple hypertrophy of
the tunic ; at another time it is owing to inflammatory phe-
nomena, with atrophy of the muscular fibres.

The internal tunic is nearly always altered. It may present
every degree of endarteritis, and of regressive metamorpho-
sis— from partial thickenings, and a white, milky tint, to ulcera-
tion, atheromatous transformation and calcification ; the latter,
however, is always rare, and may exceptionally assume an as-
pect of real ossification.

In the interior of the aneurism there is usually a fibrinous
deposit — a thrombus — always adhering, though to a variable
degree, to the internal membrane. It is more or less regular
and consistent, and partially blocks the vessels ; but there is
always a canal in the middle of the passage of blood. This
thrombus is often prolonged in the artery beyond the aneurism,
both before and behind ; and its external layers are capable of
becoming organized and undergoing softening. Its formation
is essentially connected with the presence of the worms, the
inflammatory processes, ulcerative and regressive, in the in-
ternal tunic and the dilation of the vessel. Decroly has pub-
lished a remarkable case, in which the alteration in the aorta
extended from the heart to the lumbar region.

In the aneurism, worms are found in nine cases out of ten ;
their average number is from 9 to 11, and varies between 2
and 121. When they are absent, the lesions have a chronic
character ; but when they are present, then these are more or
less acute. The parasites are young, armed sclerostomes.
They are rose-tinted, and their average length is from 1 to 3
cm. ; their sexual characters are already well defined, but their
genital organs remain rudimentary. They undergo one
moulting in this situation, in which their buccal armature as-
sumes its definite characters. Rayer and Diesing, who erro-
neously considered them as a distinct variety, named them, the
former, the strongylus armatus minor, and the latter, the scler-
ostoma armatum aneurysmaticum.

Amongst the aneurismal sclerostomes, some are almost free

10

in the cavity of the artery ; but the majority are more or less
concealed in the layers of the thrombus, the head or tail usually
projecting' into the blood stream. They are also found in the
hypertrophied walls of the artery, in either the internal or
middle coats, or between these two. Sometimes nothing is
found of them except the integuments they left after their final
moulting.

The gravity of verminous aneurism is due to the risk of
rupture of the vessels, and more especially, as Bollinger has
pointed out, to their influence on the frequency and serious-
ness of colics.

The clot formed in the interior of the great mesenteric, or
other arteries liable to these aneurisms, may throw off one or
more fragments, which are carried by the blood, and consti-
tute so many embola in the arterial ramifications passing to
the intestine. According to the size of the embolus, the ob-
literated artery is itself more or less voluminous, and the dis-
turbance set up more or less serious ; there is sudden anaemia
or ischasmiaof that portion of the intestine to which the artery
is distributed, and consequently paralysis of one or more of
the sections of the digestive tube, the secretions and move-
ments of which are suspended. Cohn and Panum have shown
experimentally, in fact, that such are the results of embolism
of the great mesenteric artery. The ischsemic portion of the
intestine becomes at first pale, then of a dark-red color ; the
mucous membrane is swollen, there are hemorrhagic infarcts,
serous exudates, ecchymoses, and sometimes a considerable
increase of the organ in volume.

These phenomena, which are almost immediately consecu-
tive, are related to the total absence of pressure in the capil-
laries of the artery, and even in the venous trunk succeeding
them, as far as the next veinule, where the circulation can go
on freely. The blood flows from this point towards the cap-
illaries, where the tension is nearly nil, and soon causes en-
gorgement, and even small hemorrhages. In consequence of
all this disturbance, there are colics, which rapidly disappear
if the obstructed artery is of small calibre ; for the collaterals
soon supplement it. The duration of these colics depends

11

upon the facility with which this collateral circulation can be
effected. It is sometimes easier in a large branch nearer the
trunk of emergence, and this explains why an attack of colic
that appears very serious will quickly disappear.

Otherwise, the establishment of the collateral circulation
plays an important part in the post-ischasmic hyperasmia ; and
this collateral or compensatory hyperaemia is related to the
increase of blood pressure in the vessels adjoining the obliter-
ated one, as Feltz has shown. When it does not produce ir-
reparable lesions the equilibrium is quickly restored, and all
trouble disappears.

The circulation disturbances of the intestine cause a local
paralysis in it, stagnation and consequent fermentation of its
contents, with an abundant production of gas. The enteralgia
induced in the healthy portions causes energetic contractions,
which frequently lead to volvulus and invaginations. Fried-
berger and Frohner have often observed the rotation on its
axis of the left part of the large colon — that is, its free portion,
which is, of all the intestinal divisions, the most liable to throm-
boses and embolisms. Paralysis of the intestine often brings
about rupture of it, the stomach, or the diaphragm, owing to
fermentation and enormous accumulation of matter and gas
therein.

In animals which have been cured of colic for some time,
old lesions in the form of thromboses are often found in the
branches of the great mesenteric artery, as well as in the cor-
responding veins, these vessels being partially or totally oblit-
erated, and around them pigmentation of the peritoneum and
other organs is usually observed. Bollinger says that on a
square centimetre of surface, there are sometimes found five
or six arterioles or veinules so obliterated.

At the autopsy of horses which have died from colic, it is
often difficult to discover the obliterated artery and the seat
of the embolus, because of the great development of the in-
testinal vessels, and more especially on account of their con-
gested conditions ; so that care and patience are needed in
this search.

The effects of the aneurisms, the thromboses, and the em-

12

bolisms, are evidently subordinate to their situation. The
presence alone of the aneurism and its clot reduces the cali-
bre of the great mesenteric artery, and consequently dimin-
ishes the supply of blood to the intestine ; this is sufficient to
explain the chronic indigestion troubles observed, and these
effects are all the more marked if the diminution in the lumen
is extended to a ramification, but they are especially so if the
vessel becomes completely obstructed by a detached frag-
ment of the thrombus. But as the arteries of the small in-
testine anastomose freely by inosculation close to the concave
curvature of the organ, embolism of one of the vessels is
never a fatal accident. It is the same with obliteration of one
of the two cascal arteries ; for the other, which anastomoses
with it near the point of the caecum, can assume its function,
so that the attacks of colic pass off. But if the trunk of the
right fascicuus of the great mesenteric artery is completely
obstructed, the cascum does not receive any blood, and death
quickly ensues. The large colon receives its blood by the
two ccelic arteries, which have an independent origin ; so that
it seldom happens that both are blocked at the same time.
The floating colon would be exempt from the danger of aneu-
rismal embolism but for its first artery, which is derived from
the great mesenteric ; the other arteries arise from the small
mesenteric, in which aneurism is rare.

In cases of death from aneurisms, the alterations described
above are most frequently found. There may also be rup-
ture of a verminous aneurism and abdominal hemorrhage.
But, as Freidberger and Frohner have remarked, embolic
colics may terminate in death in twelve to twenty-four hours,
and before serious intestinal alterations have had time to oc-
cur. The intestine is, in such cases, usually very distended
by gas, and obstructed.

Verminous aneurisms rarely give rise to characteristic
symptoms, and their presence is often only recognized when
rupture has taken place, which rapidly terminates in death
from internal hemorrhage. On the occurrence of this acci-
dent, which coincides ordinarily with a severe effort, the ani-
mal crouches or sits on its hind quarters, knuckles over at the

13

fetlock joints, and falls as if struck with paraplegia ; the pulse
is thready, limbs cold, visible mucous membranes blanched,
etc.; and, generally, the last moments of life are marked by
signs of profound and violent suffering. Aneurisms of the
aorta appear to be more liable to rupture than those of the
great mesenteric artery. As a rule, the blood flows into the
peritoneal cavity, but sometimes rupture takes place directly
into the intestinal canal. In eighteen cases collected by Bol-
linger, fifteen were of rupture into the abdominal cavity, and
three into the intestine. The latter result might be recog-
nized sometimes from the presence of blood which impreg-
nates the faeces passed before death. Rupture of verminous
aneurisms is attributable to the feeble resistance of their walls
— which have lost their elasticity and contractility — and to
the increased arterial pressure, resulting from diminution in
the lumen of the vessel.

Besides the cases of rapid death, there have been noted —
as symptoms of aneurism of the posterior aorta — decrease in
vigor of the animal, stiffness in movement of the hind quar-
ters, difficulty and pain in micturition, arching of the loins,
infiltration and intermittent lameness of one or both hind
limbs, cr-amps, and signs of paraplegia; but these indications
are not sufficiently characteristic to afford a sure diagnosis,
though they may arouse suspicions, which will sometimes be
confirmed by a rectal exploration.

Attacks of colic are the most frequent signs of vermin-
ous aneurism, and are the consequence of embolism in the
branches of the diseased vessels, but neither are these symp-
toms characteristic. Sometimes the colic is sudden and
acute, and disappears in a short time, to reappear after a va-
riable interval ; it depends upon local obstruction, which is
soon compensated for by neighboring anastomoses and is
usually ascribed to indigestion, as there is no appreciable
cause. In other cases the colics are sub-acute and a little
painful, and are due to sudden paralysis of a portion of the
intestine. Death soon follows, or the disease runs a chronic
course, and is characterized by difficult digestion, constipa-
tion alternating with diarrhoea, slight colic, some fever, and

14

a capricious appetite. It is a kind of intestinal catarrh that
may continue for days or even weeks, and terminates either
in recovery or, which is more frequent, by marasmus, cache-
kia and death.

Lastly, in some cases, the embolic obstruction of the small
arteries of the intestine, when often repeated, ends in hemor-
rhagic enteritis, to which the animal succumbs in several
days or weeks. Friedberger and Frohner attribute to this
state the following- symptoms : Diminution of appetite or
complete inappetence, increased thirsts, and rare defecation ;
the fascal pellets are small and dry at first, then become soft,
pasty, and, later, sanguinolent and foetid ; the urine is acid,
and rich in phosphates ; the fever is intense and persistent,
and the pulse small and quick ; the general debility increases,
the animal becomes emaciated, and the abdomen retracted,
and now and again there is coma. Frequently, after feeding,
there is general aggravation of the symptoms and colic.
Death is often ushered in by febrile paroxysms, muscular
tremors, shivering, coldness of the limbs, pallor of the mucous
membranes, quickened, difficult, and rattling respiration, tu-
multuous beating of the heart, and considerable elevation of
the rectal temperature.

To sum up, colics, which have their origin in disturbance
of the circulation, have no particular signs which would allow
them to be distinguished with sufficient precision in the com-
plex group of abdominal complaints.

During the series of years that I have been in practice,
the subject and treatment of colic in horses has been most
unsatisfactory to me, and the literature of our text books
would not satisfactorily come to my aid. Why, I have often
asked myself, do horses become subjects of colic ? Why do
they, as a rule, become more severe until the last when they
die ? Why is it that the usual stereotyped colic drench or
bolus will relieve, and then again it does not produce any im-
pression whatever, apparently ? Why is it that a case of colic
recovers without any notice being taken of it ?

Knowing that there is never an effect without a cause, I
began to make my post-mortem examinations with more care,

15

and open some of the leaves of the Book of Nature that I had
been in the habit of passing over.- The result of this closer
observation revealed to me the fact that the vessels supply-
ing the intestines with blood were frequently abnormal and
showed aneurisms. Opening these dilations, I found para-
sites, nematodes, and, by referring to Cobbold, found that
they were well known.

The question then presented itself to my mind, are we, as
a body of practitioners, less observing than those gone before
us? Do we look wise, give a decided opinion upon some
every-day occurrence in practice with the positiveness as
probably has been done in colics, and know as little about the
cause and lesions produced ? Are we not, as a body of veteri-
narians, more inclined to open the book of charges than that
of Nature ? Do not think for a moment that I would in the
least underrate the worth, or honesty of, the members of this
profession. I think the fault lies, if there is any, with the
authors of our standard works. In this particular instance the
subject cannot be said to be spoken of at all, and in one in-
stance, the author, in referring to it, states that it does not
occur in this country (England), although it appears quite
frequently in Germany.

In referring to the journals of the present day (in English)
one can almost count the articles on this subject on his hand,
and that being the case, 1 came to the conclusion there must
be a few veterinarians that are not aware of the importance of
this subject.

The examinations and investigations 1 have made in this
subject, with the able assistance of Dr. J. M. Parker, of Haver-
hill, only again very forcibly brings to my mind the fact that
we must not take too much for granted, but make original in-
quiry for ourselves. It is not necessary that all the work
shall have to be done with the microscope. It is not a fact,
that in making post-mortem examinations we only look for a
condition that, in our opinion, would cause death, and never
once think enough about it to look and try to find out if there
is a tangible cause for the effect produced. How often have
we made a post-mortem examination and have been unable to

16

find lesions that would satisfactorily explain the cause of
death, when, possibly, by a closer examination, the cause
might have shown itself?

Certainly there must be cause for this laxity in our post-
mortem examinations, and I am inclined to think that, per-
haps, the principal cause may be laid at the door of our in-
structors, in a great many instances ; but oftentimes the
pressure of business is the cause.

Can we afford to allow the coming generations of veterina-
rians to look back upon us as not having the same powers of
observation as the generation gone before us ? Why is it that
the Continental literature is so much more instructive than
the rest ? The articles on record regarding this malady are
interesting, but, with the exception of Dr. W. L. Williams,
they are confined to unusual cases, where the parasites are
very numerous, or the lesions gross. In Dr. W. L. Williams'
article the several cases he cites are in animals that had been
in pasture and the season wet, thus favoring, according to the
available life history of the S. armatis, the development of the
worms. From my observation, it is not necessary that the
animal should have been in pasture in order to harbor this
worm, or at least within a few years. I am of the opinion
that in the larger majority of deaths from colic, there will be
found in the blood vessels evidence of, or the parasite itself.

It is not to the exceptional cases that I desire to call your
attention, but to those of every-day occurrence.

The following cases may be of interest at this point as
giving direct evidence, in my opinion, that the worm in
question does produce lesions that are a cause of embolism.
That the parasite is a cause of altered nutrition, and in many
cases the cause of death.

i . History. — Brown gelding, ten years, one thousand pounds,
same owner for two years, never sick before with present
owner.

Found the animal with abdominal pain, sharp and inter-
mittent. Urine free, fasces scant. Looks round to the flank
continually. Eructation of gas from stomach. Treatment
would relieve for a while, but after twelve hours sickness he
died.

17

Post-Mortem— twelve hours after death. Bloated ; dark-
colored serum escapes from the abdomen when opened. The
large intestines normal in color, but distended with gas ;
small intestine black for a distance of about four feet, due to
a twist ; rest of the viscera normal. On opening the anterior
mesenteric artery, found a thickening of the intima, with a
new growth, ragged, in which were found worms.

2. History. — Brown gelding, 6 years, one thousand four
hundred pounds. This animal has been subject to fainting
spells during the last four months. He would fall down, lay
a few minutes, get up apparently all right, and resume his
work for several weeks or days.

This day he went to work apparently well, but soon man-
ifested pain, which gradually increased, with periods of ease,
until noon, when death ensued.

I found this animal bloated, in severe pain, pulse and res-
pirations hurried and short. Treatment did not produce any
apparent relief, except for a short time.

Post-Mortem—iouv hours afterwards. Bloated ; serum
escapes when abdomen is opened ; the small intestines dark
blue, the large black ; the veins of mesentery and intestines
filled with blood ; the mucous membrane of intestines black
with blood ; the sub-mucous membrane filled with straw-
colored serum ; the duodenum was contracted on itself for
about eight inches, beginning at pyloric orifice ; the thoracic
cavity contained considerable clear serum ; also the pericar-
dium, which had spots of lymph on its surface ; the endo-
cardium dark-colored, with apparently calcareous deposits in
its substance and on the valves. The superficial blood ves-
sels of the brain were filled with blood ; the third ventrical
contained some light-colored serum, and its plexus was hyper-
asmic ; the anterior mesenteric artery was the seat of an
aneurism, the walls being thickened, the intima showing a
new, ragged growth, which nearly filled its space, and was the
seat of several nematoids.

3. History. — Grey gelding, 18 years, one thousand four hun-
dred and fifty pounds. This horse has been subject to attacks
of colic during the past three or four years, and would re-

18

spond to the ordinary treatment readily. Killed on account
of lost usefulness.

Autopsy — immediately after death. Melanotic tumors
under tail and along the posterior aorta. Apparently cal-
careous deposits on the left valves of heart ; otherwise, so far
as I could see, was in a normal condition.

Dr. J. M. Parker, of Haverhill, reports the following case:

4. History. — Black gelding, one thousand four hundred
pounds. Was called at 3 p. m. Found horse thrashing and
sweating profusely and in great pain ; temperature ioo° F.;
pulse weak, and difficult to get, but about 80 to 90 per minute ;
ears and limbs cold ; membranes pale ; eyes wild and anxious ;
prognosis unfavorable. Applied hot packs and gave morphia.
Temperature gradually rose to 1020 F.; pulse more weak and
rapid ; he breathed hard, and sighed occasionally, and
trembled, but did not attempt to lie down. These symptoms
gradually grew worse, until 8:30 P. M., when he died.

Autopsy. — Body tympanitic ; abdominal cavity contained a
quantity of serous fluid ; mesenteric blood vessels filled. Small
intestines were, in places, almost black in color ; the serous
membrane showed numerous hemorrhagic spots. The serous
membrane of the colon, in region of large blood vessels,
showed exudation and extravasation of blood and serum.
The mucous membrane was easily torn, and almost black in
color, with an exudate of lymph in sub-mucous coat. Thorax
and pericardial sac each contained considerable quantity of
serum, but seemed otherwise normal. Aorta : The intima
was of an even red rose color, and on opening the anterior
mesenteric artery several warty excresences were found,
loosely adherent to the intima. The walls were much thick-
ened, and when cut open a large clot was exposed, and en-
tangled in the clot were several nematoids. The intima of
the artery above the clot was of an even red color, while im-
mediately below the clot the membrane was seemingly nor-
mal in color.

5. History. — Black gelding, sixteen j^ears ; ten hundred and
fifty pounds. For past two or three years, after having done
extra work, he would leave his feed, and in course of a week

19

or ten days would again be of service. This A. M. showed
symptoms of abdominal trouble, with acute pain, hurried
respiration and quick pulse. He did not get any ease during
his sickness, and at times was almost uncontrollable. The
duration of sickness was twenty-four hours.

Post mortem — twelve hours after death. Bloated ; dark-
colored serum escapes from abdomen when opened. Mesen-
terv dark ; both the small and large intestines were dark in
color and the mucous membrane of the same was very soft
and dark. The contents of intestines very pungent. Kidney
was soft ; liver dry and hard ; thorax contained quantity of
dark fluid ; muscles of heart soft and easily torn. Intima of pos-
terior aorta deep rose color. No evidence of strongylus
armatus found.

6. History. — Black gelding, twelve years ; eleven hundred
and fifty pounds. Been subject to colic for some time.
Called at 4 A. M. Found him bloated, cold sweat, mucous
membrane pale, pulse fast and hard, respiration quick and
labored. Died at 9 A. M.

Autopsy at 4 p. M. Bloated. Serous coat of intestines
dark blue, and blood vessels of mesentery and intestines filled
with blood. Mucous membrane of large intestines apoplectic,
with exudation of serum into the sub-mucous membrane.
Rest of viscera apparently normal. Found aneurism of an-
terior mesenteric artery ; walls thickened ; the intima showed
a new foundation, ragged in appearance, which harbored sev-
eral worms, and dark-colored clots of blood were found below
the thrombus.

7. History. — Bay gelding, twelve to fourteen years ; eleven
hundred pounds. Sick all day, not much pain, uneasy. At
8 P. M. pulse 36, respiration 18. Slightly bloated, easy passes
flatus. No fasces morning since. Gave usual treatment and
went away. 4 A. M. night man was awakened ; went to the
horse, died soon after.

Post-mortem, 11 A. M. same day. Bloated. Removing
abdominal muscles, large quantity of dark-colored serum es-
caped, undigested food around liver and stomach and small
intestines. Stomach with small rupture, the edges rough,

20

having clotted blood under external coat of stomach. Small
intestines were blushed and contained a quantity of light-col-
ored mucous, sweetish to smell. The M. M. B. of large in-
testines, colon and cascum, were apopletic, and fasces fluid.
Liver soft and friable. Rest of viscera apparently normal.
The internal lining of anterior mesenteric artery thickened, and
presented a cauliflower look, covering a space of about a
quarter of a dollar, which had in its meshes several parasites.
Growths were found on biscuspid valves, hard and glistening.

8. History. — Brown gelding, nine years ; eleven hundred
pounds. Taken sick i A. M. Saw him 3 A. M., and found him
bloated, dull pain, up and down. Pulse small, hard and 72.
Respiration labored and short, cold sweat, visible M. M. B.
pale. Usual treatment, with relief for a while, but gradually
failed, until death ensued at 8 a. m.

Post-mortem at 4 P. M. same day. Visible M. M. B. pale ;
bloated ; mucous discharge from nose and mouth. Opened
abdomen, found peritoneum itis. The colon, serous coat dark
blue ; mucous coat apopletic. Small guts, serous coat dark
in color, mucous membrane normal. Rest of viscera appar-
ently normal. Left side of heart contained a straw-colored
clot. Anterior mesenteric artery aneurismal, containing a
cauliflower growth with several small parasites, and beyond
this found a firm, dark-colored clot filling artery.

This horse was taken sick with colic the fifth ; recoverd,
went to work the sixth, but had to be returned in a few hours ;
the ninth he again resumed his work, and continued appar-
ently all right until the morning of the twelfth, when he died
as above stated.

9. History. — Bay gelding, five years ; ten hundred and fifty
pounds. Saw case at 6 P. M. Pulse full, strong ; respiration a
little hurried ; urinates freely, fasces plenty. Restless, up and
down. Prescribed for him, which gave ease for a while. 9 P.
M. — Bloated; gave drench, slacked away, and remained easy
fora while, but continued in dull pain. 1 a.m. the next day,
breathing hard and fast, sweating profusely ; again relieved
him and he remained comfortable until about 10 A. M., when
I repeated the treatment which rendered him comfortable

21

until 4 P. M., when he had a collapse without bloating. Again
did my best, which caused him to remain quiet until 4 A. M.
of the following day, when he threw himself down, pounding
his head and striking with fore feet, while the hind legs re-
mained very stiff until a short time before death, which took
place at 7 a. m. the same day.

Post-mortem — thirty hours after death. Bloated. The ab-
dominal viscera, with the exception of about eighteen inches
of small colon, were apparently normal. That part ol the gut
was inflamed and the contents dry. The M. M. B. of caecum
was well covered with dark, raised spots, and contained quite
a number of parasites.

One of the branches of the anterior mesenteric artery con-
tained a growth on its internal surface, which nearly filled its
space, and in and around this was found parasites quite active.

10. History. — Brown gelding, six years ; fourteen hundred
pounds. Taken sick about 5 P. M. Saw him at 6 p. M. Found
discharge of undigested food from both nostrils ; anxious expres-
sion. Pulse full, about 80. M. M. B. of eyes and mouth pale.
Breathing short, cold sweat, no bloating to be seen. 8 P. M,
bloated ; hurried, short breath ; pulse imperceptible ; cold ;
M. M. B. of eyes still pale, that of mouth regained color;
stands up braced. Tapped ; no relief given. Died at 9 P. M.

Autopsy next day at 1 1 A. M. Bloated ; part of small colon
protruding from anus ; opened abdomen, escape of bloody
serum and undigested food. Vessels of mesentery full of
blood, those of small intestines engorged. Colon and caecum
apparently normal, as well as kidney, spleen and liver. Stom-
ach ruptured, with blood and serum under torn edges. The
stomach contained quite a number of bots. Small intestines,
except part of duodenum, full of bloody serum. Large intes-
tines, contents semi-fluid. Cascum contained quite a number
of parasites (S. armatus). Rest of viscera apparently normal.
The posterior aorta rose color inside, and clots of blood where
anterior mesenteric artery given off. Anterior mesenteric
artery contained a ragged, new growth, with walls thickened,
but did not find a parasite.

11. Report of cases from the note-book of Dr. J. M. Parker :

22

Was called June 6th to see a case of colic, and found him
presenting the usual sj'mptoms, and no history of having be-
fore had colic. He was under treatment for eight days, with
days of ease arid apparently convalescing, but death ensued
the 15th inst. Autopsy held the following day. No bloating;
opening the abdominal cavity, there was a good deal of
post-mortem discoloration. Bowels were full of watery
faeces. Mucous membrane excoriated and much inflamed.
Diaphragmatic flexure of colon was adherent to abdominal
wall, where there was a patch of intense red discoloration,
and in the centre was an abscess opening into Ihe walls of
the colon, and containing two or three ounces of creamy pus.
On examining the aorta and anterior mesenteric artery, there
was a clot and aneurism of the cceliac branch of the anterior
mesenteric. The cceliac artery was full of dark-colored blood,
and about eight inches down a nematode was found (Filaria
papillosa). Immediately below this there was a long, slender,
straw-colored ante-mortem clot.

Dr. C. W. Stiles reports on the Filaria papillosa as follows:
" This parasite is the F. Equina? (papillosa) female. As a rule,
the nematode is found in the body cavity, but is quite fre-
quently found in the peritoneal cavity, more rarely in the
pleural cavity, of the horse, mule and ass. Generally, only a
few specimens are found in one host ; occasionally, however, a
large number are found. The female are much more fre-
quent than the male. The same parasite has also been re-
ported from the arachnoid, sub peritoneal connective tissue
and diaphragm, and the nematodes found in the eye are
thought to be embryos of this species."

Baruchello also believes that the nematodes found in the
cutaneous helminthiosis of the horse also belong to this
species.

12. Roan mare. Not subject to colic ; taken on the road ;
was very violent, and lived about four hours.

Autopsy forty-eight hours after. Portions of small intes-
tines almost black in color ; blood vessels filled. Walls of
anterior mesenteric artery thickened and roughened, with
blood clot, with aneurismal dilation about the size of a hen's

23

eeer, and entangled in the clot there were several nematodes
(S. armatns).

13. Kavanagh mare. Taken suddenly sick about 2 P.M. with
flatulent colic. Remedies such as chloral hydrate and arom.
spt. of amnion. ; later, used turpentine and linseed oil, and
carbolic acid, with rectal injections of linseed oil and trocar
and camila ; diagnosed twist of bowels. She died about 7:30.

Autopsy held next day. Showed abdominal viscera fully
distended and tympanitic ; not much inflammation ; no peri-
tonitis. In one place on intestines there was a small patch of
hemorrhagic inflammation. The gastro-splenic omentum was
intensely inflamed and dark in color. Lungs slightly con-
gested ; heart distended full. On opening intestines they
were found to contain a quantity of liquid fasces. Stomach
was distended and contained gas and fermented food. Spleen
was enormously distended, capsule tense almost to bursting.
This distension was especially well marked at the apex, where
it was full to bursting. It was here that the gastro-splenic
omentum was dark red in color and intensely injected. On
opening the posterior aorta the cceliac axis contained a quan-
tity of clotted blood, and in one of the branches the intima
was thickened and roughened in places, and adhering to and
partially concealed by the roughened intima, there were sev-
eral nematodes. The anterior and posterior mesenteric arter-
ies were normal.

14. On August 1 2th I was sent for to see a mare which I
found suffering a good deal of pain, and presenting all the symp-
toms of acute lymphangitis. Temperature, 101^-° ; pulse hard
and full, and about 60. Gave linseed oil, with belladonae and
veratrum viride, and ordered continuous bathing with hot
vinegar and water, and soap and camphor liniment.

The next day I got word that she was better ; was eating
better and seemed brighter, and the swelling was much re-
duced.

The same evening I got word to come out at once, as the
mare was down, unable to get up, and was thrashing badly.
I found her lying on her sore leg, trying to get up, and be-
coming almost frantic in her endeavors. I at once turned

24

her over on the other side, when she got up with a little dif-
ficulty and at once began eating hay, and whinnied when
water was brought.

The following morning, much to my surprise, I received
word that she was dead, and I immediately went out to make
an autopsy.

Autopsy. I found body tympanitic, swelling in leg much
reduced. Owner said she died easily, without struggling ;
so much so, that, although he was in the same barn, he did
not know she was dead till he went in to look at her. On
opening the abdominal cavity, there were no lesions to be
observed in the abdominal viscera, except one small patch of
redness, with a few hasmorrhagic spots at the pelvic flexure
of the colon. Thorax : the lungs were dark-colored and con-
gested ; the heart full on both sides. In the anterior mesen-
teric artery there were two aneurismal dilations, and in them
there were several specimens of the strongylus armatus. In
the sub-mucous coat of the caecum there were several well-
marked prominences, and through the thin membrane the
coiled-up worm could be distinctly seen. Through want of
tools and time I did not take out the brain.

15. Horse belonging to American Express Co., aged ; died
suddenly on the street while working ; (the day was cool and
cloudy ;) the horse fell down " all in a heap," with his legs
under him ; it got up again, but it immediately fell, and died
without a struggle.

Autopsy held next day, eighteen hours after death. Body
tympanitic, abdominal organs normal, no parasites in intes-
tines ; lungs congested, heart empty, muscles dark ; aorta,
normal ; kidneys, normal ; on the base of the brain around
the pons there was a quantity of congestion and effusion. In
the third ventricle, there was a teaspoonful of serous effusion.
The blood vessels in and around the vermiform process and
the lateral lobes of the cerebellum were intensely congested ;
No strongyles were discovered.

Post-Mortem of Horses Found at the Knacker.
Brown gelding ; aged ; killed ; S. Armatus abundant in
csecum ; aneurism, anterior mesenteric artery with worms.

25

Gray mare, over drove ; died of exhaustion ; no evidence
of S. armatus in caecum ; small aneurism, anterior mesenteric
artery, but no evidence of parasite there.

Owner unknown ; died of colic ; apoplexy of large intes-
tines ; S. armatus plenty in caecum ; anterior mesenteric arte-
ry aneursmal, with worms.

Bay gelding, old owner unknown ; died of colic ; aneu-
rism post aorta at point where anterior mesenteric artery
given off, size of a large pear, involving anterior mesenteric
artery, with thrombus and strongyles present, and one of di-
verging arteries completely plugged ; no S. armatus found in
caecum.

Bay gelding, killed for lost usefulness ; strongyles in cae-
cum ; aneurism anterior mesenteric artery, with thrombus
and strongyles.

Gray gelding, died from effects of heat ; no evidence of
parasite in question.

Mr. Mather, M.R.C.V.S. in Veterinarian for 1857, Vol.
XXX., page 190, writes as follows :

" About twelve months since, when practicing in the
South, the following cases came under my notice, and never
having read in any of our veterinary works, or heard men-
tion made, of such a disease (excepting that veterinary sur-
geons had occasionally met with it), I thought perhaps you
might deem the following particulars not unworthy of a place
in the Veterinarian.

" It was thus only by chance that I was enabled to learn
the nature of the complaint the animals were laboring under,
and that in the following manner : The subjects of the dis-
ease were blood foals varying in age from seven to sixteen
months, and one of them having been found dead in the field,
I was sent for to make a post-mortem examination, it being
suspected that the animals had been poisoned. On examin-
ing the foal previously to opening it, I found the body to be
very much emaciated, and that the abdomen was greatly en-
larged. On percussion of the belly, I detected the presence
of a small quantity of gas, mingled with a fluid which I con-
cluded was of a serous nature. From this circumstance, I

26

came to the conclusion that the animal had died from ascites,
but on opening it, I found the abdomen to contain quite a
gallon of pure blood. On removing the viscera, I at once
saw that the hemorrhage had come from a rupture of the
posterior aorta, just in front of the renal arteries. I dissect-
ed out the vessel to nearly its whole length, and on examin-
ing it, I thought at first that simple aneurism existed ; but on
cutting into dilated portion, near to the rupture, I found,
much to my surprise, that the vessel was completely choked
with myriads of small worms, similar in appearance to the
filaria which we find in the bronchial tubes of calves suffering
from bronchitis or husk. The internal coat of the vessel was
considerably thickened ; in fact, it appeared to be lined with
a false membrane, which, no doubt, had been caused by the
irritation set up by these creatures. In all of the arteries
given off the main trunk were more or less of those parasites.

" About a fortnight from the time of being called to
this case, I was sent for to see another of these foals, which,
the man informed me, had been found down and unable to rise.
On examining it, I observed that the pulse at the jaw was
nearly imperceptible, the mucous membranes blanched, and
the body very cold. I informed the owner that I was sure
the foal was dying from internal hemorrhage, and that, in my
opinion, it was suffering from the same complaint as the last.
We managed, however, after some difficulty, to get the ani-
mal on his legs again, and immediately we had done so, it
commenced voiding a large quantity of blood from the penis.
Seeing that there was no chance of recovery we had the foal
destroyed, when I made my examination and found the blad-
der distended to repletion with blood. The right kidney was
twice its normal size, and on cutting into it I found it filled
with similar parasites. The renal artery was quite as large
as one's finger, and it, also, contained a large number of these
creatures. The posterior aorta contained thousands of them.

" Two other foals, which were on the premises, I felt sure
from their appearance were laboring under the same com-
plaint, and the owner wished me to try if I could do anything
for them.

27

" I must here say that these foals had been taken off the
mares at about six months old, and placed on some cold, wet
lands, where they had remained up to the time of my seeing
them.

" The two surviving ones I had taken up and put into the
bay of a barn, so that they could be supplied with crushed
oats, pea meal, and good hay. I first gave them, for three
successive mornings, ol. tereb., ol. lini., and afterward admin-
istered for a few days the following tonic — ferri sulph., pulv.
gent. These remedies were alternately employed for a fort-
night, and I considered that the animal was improving under
their use, but at the time the owner saw fit to dispose of the
foals, so that I afterward lost sight of them entirely."

[Editor. — Mr. Mather will find in the records of Veter-
inary Medicine, several analgous cases to those he has related
They are not uncommon, and have frequently been brought
before the notice of the students of the college by the profes-
sors.]

Dr. W. L. Williams in his article says :

" How often these parasitic thrombi occur amongst our
horses, we do not attempt to say ; we have only looked for
strongyles where they have been expected, and have not been
disappointed in any case. A positive diagnosis is generally
available, by manual exploration per rectum, or by pulse, and
respirations are more uniformly accelerated than in colic, and
there is a peculiar, anxious expression about the animal that
bodes no good, and leads one to conclude that he is dealing
neither with ordinary colic nor enteritis."

I think Dr. Williams is right when he says, " we do not know
how often these parasitic thrombi occur amongst our horses,"
for the reason that there has never been enough careful post-
mortems to answer the question. I am not surprised that he
finds them so readily when looking for them, for he says, "where
expected they were always found."

I must differ with him when he says a positive diagnosis is
generally available, by manual exploration per rectum, or
pulse, respiration, and general expression of the animal. I
think that, in most cases, the diagnosis follows death, although

28

one is justified in expecting the presence of the parasite in
the majority of cases that die from colic.

Dr. A. W. Clement, in Journal Comparative Medicine and
Surgery, Vol. XIII, page 186, cites a very interesting case of
rupture of the anterior mesenteric artery, but here no unusual
case present itself.

Dr. J. T. Duncan, in Veterinary Journal, March, 1887, cites
several interesting cases that do not correspond to the every-
day occurrence of the practitioner, although the lesions pro-
duced were due to S. armatus.

Dr. R. W. Burke, in Journal Comparative Medicine and Sur-
o-ery, Vol. XIII, has an article on this subject, but does not
cite any cases that have come under his observation.

Dr. C. A. Cary, in the same journal, June, 1892, cites
two post-mortems of colts that never had colic ; one died from
tetanus, the other was killed on account of malformation,
with aneurisms of anterior mesenteric in both, and living
sclerostomes. Using these cases for an analogy, he thinks
that the theory of verminous aneurisms causing colic should
be more carefully looked into.

Mr. M. Laquerriere, in his article on colic, Veterinary
Review, Vol. IX, page 222, says — " As to the predisposition
produced by a diseased condition of the great mesenteric artery
(aneurism), upon which Zundel places so much weight, we at-
tach but little importance to it. But, on the contrary, we
recognize the predisposition accompanying advanced age."

Prof. F. Smith, Army Vet. School, Aldershot, has a very
interesting article in Veterinary Journal, for July, 1892, on " In-
testinal Obstruction in the Horse," and I fail to find that he
makes mention of Strongylus armatus as a cause for the same.
He does say that " The rapidity of death depends entirely
upon whether the blood supply to the bowel is partly or com-
pletely cut off, viz., a partial or complete twist." I am of the
opinion that the twist to which he attaches so much import-
ance is a result due to enteralgia, and that due to altered
nutrition of the part. It is a fact that this parasite is not a
stranger, but is readily found if looked for, and is a cause of
thrombosis and embolism.

29

Mr. Hunting, in discussing Prof. Smith's paper, " held that
the impacted food was the cause of the spasm, or the pain, and
that the proper thing was to remove the cause, even if they
inflicted a little more pain." Does not the establishment of
collateral circulation to the afflicted parts cause a return of
normal state, and pain then cease, allowing that it is due to an
embolism ? Who can make a positive diagnosis of this condi-
tion during life ?

Mr. H. G. Rogers said he was rather skeptical as to the
condition called twist, for the report came from Knacker in
abdominal cases—" Twist, sir ;" and this is similar to the report
from this side of ruptured diaphragm. He thought that slug-
gish liver and defective teeth were the causes of intestinal ob-
struction.

Prof. Macqueen thought there was another form of ob-
struction which demanded a little more attention than it
usually received, and that was the form of obstruction due to
aneurism of the branches of the mesenteric artery. He sug-
gested that more careful post-mortems might reveal a cause
that is often overlooked.

Dr. Wm. Willis, M.R.C.V.S., in Veterinary Record, July
1 6, 1892, in criticising Prof. Smith's paper, remarks the entire
absence of any reference to the condition of the circulatory
apparatus of the bowels. He says, " I am inclined to think
mesenteric aneurism is much more frequently responsible for
the death of our patients than is generally supposed. Cer-
tainly, it is not the rare disease of old horses which the scant
notices of our text books might lead one to believe. It is a
most common condition. Physiological experiments teach us
that when the blood supply to the bowel is suddenly inter-
rupted, violent intestinal movements result, and that, if the
interruption be continued, a paralytic condition of bowel re-
sults. I would suggest that the first result is probably the
precursor of twist, and the second is certainly the explanation
of some cases of obstructed colon.

" How far mesenteric aneurism, thrombosis, and embolism,
are likelv to give rise to the conditions referred to above, and
to what extent they must be held responsible for the fatal ter-

30

mination of many of our bowel cases, is a matter which de-
serves more attention at the hands of the British veterinarian
than it has hitherto received."

Dr. Willis cites seven post-mortems ; five eight years old
and under; two more aged. He found six with aneurisms,
one of them with strongyles ; the other one revealed a per-
fectly round hole about the size of a sixpence, in the side of
the ileum, near ileo-csecal valve. I am of the opinion, had
his examinations been made with a little more care, he would
have found the worm in each case ; although not necessarily
at the point of aneurism.

J. E. Miller, M.R.C.V.S., in Veterinary Record, June 18,
1892, cites an exceptional case of mesenteric tumor with
aneurism of anterior mesenteric artery.

Cobbold says : So practically important, however, do I
deem Bollinger's summary of the whole subject in relation to
the hippopathological aspects of parasitism, that I feel it de-
sirable to record his conclusions at full length. No profes-
sional man having any pretentions to a knowledge of the vet-
erinary art — or, for that matter, to parasitism in relation to
sanitation — should remain uninformed on this subject. Dr.
Bollinger's results are thus stated :

1. The worm aneurism of the visceral arteries of the
horse, existing in 90 to 94 per cent, of adult horses, has a gen-
eral correspondence with the aneurisma verum mixtum of
man. It is, however, distinguishable from the same by its
seat, cause, character of its walls, contents, and mode of ter-
mination. The worm aneurism arises from a parasitism of
the palisade worm (Strongylus armatus), owing to an inflam-
matory affection of the arterial walls which it causes, and
which one may describe as a recurrent traumatic endo-
arteritis. This holds good for all the visceral arteries, with
the exception of the abdominal aorta, in which an aneurism
may arise from local increase of pressure.

2. The formation and further development of the aneurism
is also favored by the narrowing of the arterial calibre, which
is caused by the inflammatory swelling of its walls, and also
by the contemporaneous formation of a thrombus (clot), this

31

latter still further supporting and exciting the inflammation
of the inner coat.

3. Whilst the causes above mentioned (and of these more
particularly the continued presence of the palisade worms
and the plugging of the smaller arteries by thrombi) favor
the growth of the worm aneurism, the small size of the same,
notwithstanding the years it has existed, is explained by the
considerable hypertrophy of the muscular layer, by the tough
fibrous capsule formed in many cases by the connective tissue
of the mesentery, and by the adhesion of the intestines to the
perpendicular and free-lying anterior mesenteric artery ; in
particular this last named circumstance does not allow of any
very considerable shortening of the mesenteric artery, which
would necessarily be accompanied by considerable dilation ol
the arterial tube.

4. The favorite seat of the worm-aneurism is the trunk of
the anterior mesenteric artery, directly at its origin from the
abdominal aorta. Most frequently that part of the arterial
trunk is dilated from which the arteria ilea, caecales and colica
inferior (arteria ileo-caeco-colica) arise, less frequently the
arteria colica superior at its origin, and the arteries of the
caecum and colon in their course in the meso-csecum and meso-
colon. The verminous aneurism also occurs in the cceliac ar-
tery (Bauchschlagader), in the posterior mesenteric artery
(Gekrosarterie) in the renal artery, and in the abdominal
aorta. A horse is not infrequently afflicted with several
aneurisms of this kind at one and the same time. Thus in
one case (described by Bollinger) there were six of these
aneurisms affecting the abdominal aorta and its branches in
the same horse. The verminous aneurism may occur from
the sixth month of life onwards, and with increasing age ; the
number of horses free from such aneurisms becomes contin-
ually smaller.

5. The aneurism varies in size from that of a pea to that of
a man's head. The dilation is, as a rule, equal on all sides,
the form being usually thumb-shaped or bottle-shaped, passing
into that of a cone or long oval figure. This general configu-
ration is principally due to the free and movable situation of
the anterior mesenteric artery.

32

6. In contrast to aneurisms in man, the walls of the worm-
aneurism in the horse are almost without exception indurated.
In addition to the mesenteric connective tissue, all the arterial
coats, and especially the tunica media, generally take part in
this induration. The hypertrophy of the media, which stands
unique in respect of what is known of arterial disease, forms
a compensatory action of the arterial wall, analogous to the
muscular hypertrophy of the heart in valvular disease. This
change in the media points to the fact that in the develop-
ment of aneurism in man the early disturbance of the nutri-
tive process in the tunica media is not a less essential factor
than the degeneration of the tunica intima.

The changes in the intima are the least constant. They
present all stages of progressive and retrogressive metamor-
phosis, from simple induration to ulceration and calcification.
In the walls of the verminous aneurism one not unfrequently
finds all the pathological changes exhibited by atheroma in
man. Calcification is a common form of the retrogade pro-
cess, and, in very rare cases, may pass on to the formation of
true bone.

7. In addition to the palisade worms, one almost con-
stantly finds a parietal thrombus contained in the aneurism.
It covers the inner wall either partially or completely, being
in the latter case perforated for arterial offshoots. The clot
may occlude the artery, and it is not unfrequently continued
into the arterial branches (peripherally) or into the aorta
(centrally). Amongst the various changes that the clot under-
goes, organization of its outermost layer and softening are the
most frequent. The constant occurrence of this clot is due to
the presence of the worms, to the inflammation, ulcerative
and regressive affection of the intima, and to the dilatation of
the arterial tube.

8. The palisade worms are seldom absent from aneurisms
of the horse. Their not being present is merely an accidental
circumstance. On the average, nine palisade worms go to a
verminous aneurism, and eleven in the horse. The highest
number of worms found in one horse reached 121. Not in-
frequently, also, palisade worms, or their coverings in the

33

form of larval skins, are found in the aneurismal walls. The
immigration and emigration of the palisade worms out of the
intestine into the aneurism, and the reverse, takes place,
probably, as a rule, within the arterial circulation. The path
of the worm does not appear to be always the same, inasmuch
as they can also wander through the peritoneal cavity. The
worms found in the aneurismal walls are probably mostly
only strayed specimens.

9. From a comparative pathological-anatomical point of
view, the developmental history of the aneurysma vermino-
sum proves that a circumscribed endo-arteritis can determine
the formation of an aneurism.

10. Like the worm-aneurism itself, atheroma of the ab-
dominal arteries arises from a circumscribed acute and sub-
acute endo-arteritis. The histological changes in the second-
ary atheroma of horses are perfectly analogous to those of
the spontaneous atheroma of man. Idiopathic atheroma, as
seen in man, does not occur any more in the horse than in the
other domestic animals. Atheroma in the horse is always
secondary. To be sure, one observes an idiopathic chronic
endo-arteritis in many abdominal arteries of the horse, which,
however, never exhibits indications of atheromatous degen-
eration.

11. In consequence of its position, the worm-aneurism of
horses is not open to physical examination, and, on that
account, cannot be diagnosed by physical signs ; moreover, it
offers no characteristic symptoms. Its termination by rup-
ture is extremely rare, the aneurisms of the abdominal aorta
being more disposed to rupture than those of the anterior
mesenteric artery. Of eighteen cases of known perforation,
fifteen opened into the peritoneal cavity, and three
into the bowel. The dangerous symptoms of the
worm-aneurism are exclusively due to embolism and
thrombosis of the affected artery, arising from the parietal
clot. The latter becomes especially dangerous through its
increasing size and the softening which accompanies it. The
absorption and shrinking of this parietal clot, be it organized
or not, is materially assisted by the high pressure to which it is
exposed.

34

12. The very marked symptoms of vascular obstruction — ■
the sero-hemorrhagic intestinal infarct — in embolism and
thrombosis of the mesenteric arteries, are easily explained by
paralysis of the muscular coat of the intestine, by the absence
of paucity of valves in the portal vein, by the readiness with
which meteorismus (orflatus) arises, especially in herbivora,
and by the loose consistence of the intestinal walls of villi.

13. The occlusion of the intestinal arteries, especially that
arising suddenly, always has for its result a partial or com-
plete paralysis of the portion of bowel which they supply.
The palsy of the intestine causes the forward movement of
the intestinal contents to cease, a stoppage of the fasces, a
hindrance to the discharge of fasces and gas, and also that ex-
ceedingly dangerous formation of gas (within the intestinal
tract) which in the herbivora is so abnormal, both quanita-
tively and qualitatively.

14. In embolism and thrombosis of the mesenteric arteries
the symptoms during life are entirely identical with those
observed in the so-called colic of horses, as has been de-
termined by numerous observations. The partial paralysis of
the bowel, which is brought on by the embolism and throm-
bosis of the mesenteric arteries, forms in great part the chief
and leading feature of the series of symptoms known as the
" colic " of horses. The palsy of the bowel which arises this
way may explain also the frequent ruptures of the digestive
canal and the greater number of its changes in position. The
latter are specially favored by the structure of the abdominal
viscera in the horse.

15. The old changes which one finds in the peripheral
branches of the anterior mesenteric artery, in the form expired
and partly absorbed embolic and thrombolic processes (pig-
mentation, arterial and venous thrombi), particularly in con-
nection with those arteries which are seats of the aneurism,
decisively prove that the large majority of colics resulting in
recovery, so far as they do not depend upon known injuries,
are caused by paralysis of the bowel from embolism and
thrombosis. The sudden occurrence, course, and result of
these kinds of colics also testify to their embolic origin.

35

1 6. The cedematous, inflammatory, and hemorrhagic pro-
cesses that one often finds described as the cause of death in
colic, almost exclusively depend on thrombosis and embolism
of the mesenteric arteries, the cases forming about forty to
fifty per cent, of all fatal colics.

17. The rapid course in fatal colics, as well as the pre-
ponderating symptoms of dyspnoea in cases of recovery, is
finally due to the abnormal development of gas in the alimen-
tary canal. In addition to the diminution of the respiratory
surface by the lofty position of the diaphragm, a direct poi-
soning (carbonic acid and sulphuretted hydrogen), probably
contributes to the intensity of the symptoms and the rapid
course by diffusion of the abnormally developed gas out of the
intestinal canal into the blood.

18. The variety of the anatomical derangements caused by
embolism and thrombosis of the intestinal arteries is faithfully
mirrored by the variety of the clinical symptoms and the dif-
ferent degrees in the intensity and course of the colic,

19. Amongst every 100 horses afflicted with internal dis-
ease, 40 are ill with colic. Among any hundred deceased
horses, 40 have perished with colic, and among 100 colic pa-
tients, 87 recover and 13 die. The figures prove that neither
amongst the epizootic nor sporadic diseases of horses is there
any other affection which occurs so frequently, or claims any-
thing like so many victims. -Like the frequency of the worm-
aneurism, the amount of disease and mortality increases with
advancing age. The etiology of the colic of horses finds in
the thrombosis and embolism of the mesenteric arteries, with
the consequent paralysis of the bowel, an all-sufficient expla-
nation, whilst the causes of colic hitherto accepted were, for
the most part, insufficient.

20. In a great number of cases, the thrombus of the worm-
aneurism is continued past the mouth of the anterior mesen-
teric artery, into the lumen of the aorta, and, as such, is the
exclusive cause of the embolisms of the pelvic and crural ar-
teries which bring about the intermittent hobblings (the
author savs " intermitterenden hinken," not " hahnentritten,"
the usual equivalent term for springhalt). Considering the

36

excessive frequency of the thrombus being continued into the
aorta, it becomes highly probable that a great part of the dis-
eases and lameness of the posterior extremities (" Huft und
Kreuzlahme, unsichtbarer Spath, etc.," which may be ren-
dered "sciatic and hip or spinal lameness, obscure spavin, etc.,")
are due to occlusion of the arteries.

21. Owing to the fibrous thickening of the connective
tissue of the root of the anterior mesenteric round the
aneurism, and to the considerable size of the latter, disturb-
ances of the innervation of the intestine, (as well as) hind-
rances to the passage of the chyle, and irregularities in the
portal of many chronic disturbances of digestion in horses.

22. Considering the great losses and heavy social disad-
vantages that are occasioned by the colic of horses to the
horse-breeder, to agriculture, and to the general welfare, it is
ot the highest importance to discover means which should
prevent the introduction of the embryos with the food, and,
as a consequence, the migration of the palisade worms into
the mesenteric arteries of the horse.

In calling your attention to this subject, old as it is, I hope
I have not encroached too much on your valuable time. If I
have been able to cause one of you to ask yourself: Can
the statements made be sustained by post-mortem examin-
ation?— for I think we have been able to — then, with the
interest of your profession at heart, I hope you will open the
Book of Nature, and determine the fact for yourselves.

EXPLANATION OF PLATES.
Plate I.

Fig. 1. — Male: a, caudal pouch ; b, spicula.

Fig. 2. — Female : a, vulva ; b, anus.

Fig. 3. — a, capsule ; b, longitudinal line or rib ; e, anterior teeth ; d, anterior
cilia ; e, papillae ; /, posterior papillary bodies or plates ; g, anterior
armed pharyngeal ring; h, pharyngeal capsule; k, anterior con-
stricted portion of oesophagus ; I, posterior ventricle or bulb.

Fig. 4. — c, anterior teeth ; d, anterior cilia.

Fig. 5. — b, longitudinal line or rib ; /, posterior plates.

Fig. 6. — Anterior cilia.

Fig. 7. — Anterior papillae.

Fig. 8. — Fine anterior teeth.

37

Fig. 9. — Caudal pouch of male ; b, spicula.

Fig. 10. — Posterior moiety of female ; b, anus.

Fig. 11. — Undeveloped or agamous worm, in thin transparent membrane, which

is shed on reaching maturity.
Fig. 12.— Ovum.

{These drawings are original, and made by Dr. J. M. Parker.)

Plate II.

Fig. 1. — Caudal extremity of the male Sclerostoma equinum (Neumann.)

Fig. 2. — Fragments of the ccecum of a horse showing the tumors of different

sizes due to the sclerostomes, as well as parasites fixed on the mucous

membranes (Neumann.)

Plate III.
Fig. 1. — Verminous aneurism of the great mesenteric artery; one-half natural

size (Railliet.)
Fig. 2. — Abdominal aorta of a horse with its ramifications (Neumann.)

PLATE II

Fig. I

Fig. II.

Tig-F

a a

c C