NationalLibraryOfScotland/medical-history-of-british-india huggingface dataset:
Scientific Memoirs by
portion of each section was seen to be occupied by cicatricial tissue, often
placed so superficially as to entirely block up the openings of the peptic glands.
When first I met with these gastric worms, the wide difference of their habitat
from those first met with in the lower bowel made me suspect that I might have
to do with a distinct species ; but a subsequent close comparison of specimens
from each situation convinced me of their specific identity, and, though it is
extremely rare to find any of them in the small intestine, I have since met with
a few specimens apparently on their way from stomach to colon, and also a few
stray, scattered worms encysted in the submucosa of this portion of the bowel.
While, however, this latter occurrence serves as a connecting link between the two
commoner situations, it is so exceptional that it must be considered abnormal.
Although the submucosa of the stomach, and occasionally of the small
intestine, serve as localities for the encystment of the young parasites, the condi-
tions met with within the lumina of these viscera do not appear to be suitable to
their prolonged residence when they have escaped from their cysts. None of
the worms found free within the stomach had attained their full growth, and as,
to all appearance, they do not take up the habit of blood-sucking until quite fully
grown, no worms will be found adherent to the wall of the stomach, even in a
body opened immediately after death.
In the great intestine too, besidesf ully grown worms gorged with blood,
and still adhering to the mucous membrane, much greater numbers of smaller
ones will be found free in the bowel, whose intestines show no evidence of blood-
sucking propensities. These smaller worms seem to subsist on the nutritive
fluids with which they are surrounded, and are never, so far as I have seen, to
be found adherent to the mucous membrane.
Though not fully grown, these small worms are sexually mature, and may
so often be found in copula that it is rather the rule to find them so than otherwise,
and the adhesion between the couples is so firm that hardly a doubt can be
entertained that their union is assisted by some viscid secretion. Indeed the
fact that it persists long after the death of the worm, when all muscular contrac-
tion must have ceased, almost proves this to be the case. All worms met with,
free in the intestine, whether full-grown or otherwise, are sexually mature, though
it is possible that they may not begin to lay their eggs until, with complete
growth, the power of gaining a more abundant supply of nourishment is acquired.
It is while encysted that the changes that lead up from the already de-
scribed Rhabditis progeny to sexual maturity take place, and hence the statement
in Cobbold's " Parasites" ( fide Leuckart ) that " The development of the
sexual apparatus had not yet commenced is a mistake, arising probably from the
limited material for observation at his command. So far from this being the
case, it is rare to find an encysted worm in which the sex cannot already be
made out, provided attention be paid to the position of the rudiment of the
Medical Officers of the Army of India.
15
generative gland ; and all stages, from indeterminate Rhabdites still provided with
the hollow styloid mouth armature, to sexually mature parasites, just ready to
escape with a nearly complete dental apparatus are to be found. The speci-
men figured for example, though far from sexually mature, is quite clearly a
female, the generative aperture being already clearly discernible about the
middle of the body, though the generative gland itself, as far as its histiologi-
cal elements are concerned, might be either testis or ovarium. In spite of this,
taken as a whole, the sex of the animal might be diagnosed from an exami-
nation of the gland alone, for the most advanced cells are placed in the middle
of the organ and not at the aboral extremity, as would be the case in
a male histologically indeterminate gland.
While encysted, the little worm undergoes several changes of skin, and, by
the time it is ready to escape, is fully equipped with the peculiar mouth arma-
ture of the adult. The buccal cup first appears as a quite unarmed cavity.
Next, the circlet of minute denticles, that comes behind the circlet of fimbrix
in the adult, is developed. The four labial spines next appear, but are rather
papillæ than spines at this stage ; and, finally, the circlet of fimbriæ and the
ring of plates round the pharyngeal opening, made their appearance. Probably
more than one ecdysis is undergone by the worms after escaping from
encystment, for specimens undergoing the process are not hard to find, though
I was unable to satisfy myself of the occurrence of the so-called cocoons de-
scribed by Cobbold.
Appearances that might be interpreted somewhat in this fashion I have
indeed met with ; but they appeared to me to be better explicable as acci-
dental accumulations of fæcal matter round a worm undergoing ecdysis.
Nematodes undergoing this process are always in a very sluggish state, and
so would more readily serve as the nuclei of such concretions than the actively
moving creatures they are when not so engaged ; but I must repeat that I look
upon the occurrence as purely accidental, as worms changing their skins were
far more commonly to be found without any such encumbrance than with it.
Thus it will be seen that, during the life-history of this worm, it inflicts two
serious lesions on the intestine. First, it bores its way into, and encysts itself
within the substance of the mucous membrane, setting up changes which
result in the certain impairment, and often entire loss, of functional activity in
the little patch of digestive mucous membrane affected ; and secondly, it, with the
powerful teeth of the fully grown worm, gnaws into the mucous membrane
and continuously sucks its victim's blood, and, as the period of sexual vigour
during which the worm exhibits this blood-sucking propensity is probably a
tolerably long one, this second class of lesion is one which must be again and
again inflicted by the same worm.
In the face of these facts it appears difficult to understand how any one
can doubt the ability of this parasite to bring about a fatal result.
16
Scientific Memoirs by
No one now doubts the ravages wrought in the human subject by Doch-
mius duodenalis, and yet the equine parasite is absolutely much larger, and,
even relatively to its larger host, at least as large as the human scourge ; added
to which, it is generally present in numbers which put the worst cases of
an chylostomiasis into the shade.
Cobbold, indeed, recognises that it has caused " virulent epizootics " in Eng-
land ; but, in spite of his teachings, the pathological importance of the worm
appears to be but little recognised, at any rate in India.
Shortly after I had made out that the so-called " Surra " among the
transport animals at Shillong was really sclerostomiasis, I wrote a short letter
to the " Pioneer " with the view of ascertaining whether or not similar cases had
been met with elsewhere.
My object was to collect information through ordinary correspondence,
and nothing was further from my intention than to enter into a public contro-
versy, at any rate in the columns of an ordinary newspaper, which, though
well suited for a notice of enquiry on any subject, is recognised as hardly a
suitable medium for a discussion of so essentially technical a character. In
place, however, of sending me the results of his experience in letter form,
Mr. Steel, the well known and learned head of the Veterinary College at Poona,
replied in the columns of the " Pioneer " in a way that showed he entirely mis-
understood me, for he was clearly under the idea that I had propounded the thesis
that all " Surra" was sclerostomiasis, whereas all I had asserted was that certain
cases which had fallen under my own observation, and were shown me as
instances of that disease, were of that nature, and had asked for information
as to the prevalence of the parasites elsewhere.
I have no desire to re-open a controversy based entirely on a misconcep-
tion of my views, nor should I allude to the incident here were it not that
Mr. Steel's letter may, I presume, be taken to fairly represent current veterinary
opinion on the subject, and he definitely commits himself to the assertion that
the strongyles in question are " inadequate to explain the phenomena of Surra."
Now, as I gather from Veterinary Surgeon R. W. Burke's excellent little
work on " The tropical diseases of the Horse," the characteristic phenomenon of
"Surra" is an inexplicable pernicious anæmia ; in fact, his chapter on the subject
is headed " Surra, or pernicious Anæmia," and the adequacy of these strongyles
to bring about a pernicious anæmia is a matter on which incredulity is difficult
to understand.
It may be, however, that Mr. Steel's meaning is that the existence of the
strongyles will not explain the presence in a large proportion of cases of
the so-called " Surra parasites" ( Trichomonas Evansi), and of course there
can be no possible connection between the two organisms ; but, until these
monads have been cultivated apart from their host, and a pernicious anæmia
produced in a healthy animal by infection with a pure cultivation, the connection
between monad and disease must remain a mere matter of opinion.
Medical Officers of the Army of India.
17
As is well known, these monads are congeneric, and more than probably
conspecific with certain morphologically identical organisms found by Crook-
shank and others in the blood of healthy rats, and if they be really so harmful to
horses, the immunity of the rats is very hard to explain. So that whatever pro-
portion of the group of cases popularly called " Surra " may be attributable to
sclerostomiasis (and it is very probable that several distinct causes of pernici-
ous anæmia may contribute to the total), I should personally prefer to look
upon the coincidence of the presence of monads in the blood as accidental, until
a rigid demonstration of a causal connection be forthcoming. The most that
can be said of the researches of Evans, Steel, and others on this point is that
they are suggestive of the possibility of a causal connection between the monads
and the particular set of cases under their observation.
This applies especially to their inoculation experiments, which, being con-
ducted with blood, might bring about deaths by some form of septicæmia ; and,
putting this aside, it must be remembered that such a fluid, besides the monads,
might contain some unsuspected bacterium which might yet be the true cause
of the fatality in the group of cases they were observing.
I regret to say that I got but few communications in reply to my query in
the " Pioneer "; but those I did receive are sufficient to show that the strongyles
in question are very common in Burma.
Of especial interest were two letters I received from Dr. Hendley, who was
associated with Dr. Evans in his researches on "Surra " in Burma.
Dr. Hendley is, of course, strongly predisposed to the view that the fatality
in the cases he observed was referable to the Trichomonas Evansi ; but the
following passages are remarkable, as they clearly show that entozoa were
present in some at least of their cases. He says : " In the first cases examined
we noticed large numbers of small, round, whitish worms, from half to one and
half inches long, imbedded in clusters in cyst-like spaces in the stomach and
associated with them, but often without them, ulceration of that organ. These
conditions were found in old standing cases, and at first led us to believe that
they might be the cause of the disease. However, we discarded the idea when
they were not found in cases killed earlier in the course of the complaint. At
this lapse of time I cannot say that the whole length of the intestine was slit
open in each case ; but the examination was generally fairly thorough."
Elsewhere Dr. Hendley remarks : " The stomach and liver appear to be the
organs most affected in the body, and ulceration, due to progressive anæmia in
the former organ, is one of the most important post mortem appearances in long
standing cases."
Now, the condition of the stomach here described is thoroughly characteris-
tic of sclerostomiasis ; and that worms should be found actually in the stomach
in only a small proportion of cases coincides exactly with what I have observed
at Shillong, while marks of their previous presence were found in every case
D
Medical Officers of the Army of India. 19
Of the prevalence of the parasite in parts of Assam outside the Khasia hills,
I obtained evidence in a very interesting letter from Dr. Rudduck of Meesa.
Some years ago he had lost several horses from " Surra " and, on making a
thorough examination, he found the only obvious cause of death was the presence
of immense numbers of small worms in the cœcum and colon. He preserved some
of these, and sent them to " a well known veterinary firm in Calcutta," who re-
ported that two species were present, one of which was the common Oxyuris
curvula, and the other was "unknown."
The pressure of other work prevented Dr. Rudduck from following up the
investigation, and hence he did not publish, or make any further effort to ascer-
tain the character of the " unknown " species ; but, when visiting me in Shillong,
he at once recognised my specimens of Sclerostomum tetracanthum as being
identical with the unknown species that had played such havock in his stables.
Few in number though they be, these communications go far to prove
the prevalence of the parasite throughout. Assam and Burma, and, wherever
prevalent, a severe fatality among their equine hosts follows as a necessary con-
sequence.
Further, the very paucity of the number of communications clearly de-
monstrates how little attention has been bestowed upon parasitic disease among
animals in India. Whether these cases should rightly be called " Surra " or not
is a matter of the smallest moment ; the important fact remains that the
parasite in question is a source of serious mortality among equine animals in the
tracts of country mentioned ; and all that remains to be considered is how far the
recognition of this fact can help us in the treatment and, more important still, in
the prevention of the malady.
In the treatment of a disease such as that under consideration the import-
ance of forming an early diagnosis is obvious, for the injury caused to the
digestive organs by the prolonged presence of the parasites is so serious that
the mere expulsion of the worms at a late stage of the disease cannot be ex-
pected to effect a cure, as the injured organs will have become incapable of
assimilating fresh food to make up for what has been lost. Hence, in countries
where these worms are known to be prevalent, animals should be carefully
watched and treated promptly, more especially in the direction of preventing
further infection. Pressure of other work made my clinical observations
scanty and incomplete ; but, so far as they go, I am inclined to think that irregu-
lar feverish attacks form one of the earliest indications that something is amiss.
These feverish attacks, I take it, are brought about by the migration of succes-
sive batches of parasites into the submucosa.
As the initial lesions are quite identical with those caused by Trichina
spiralis, in which the boring of the parasite through the intestinal wall almost
uniformly determines feverish symptoms, this is only what might be expected.
Hence attacks of fever, occurring in equine animals in any region infected
D 2
20
Scientific Memoirs by
by the parasite should be viewed with suspicion, and measures taken to ascer-
tain its presence or absence, and owing to the immense numbers of ova produced
by them, the determination of this point, by microscopical examination of the
dung, is a perfectly easy matter. Owing to the large size of the ova, the lowest
powers suffice for the purpose, and the readiest way of making the examination is
to stir up a little of the dung in a shallow glass tray containing water, by which
means a comparatively large quantity can be searched over in a short time.
The measurements and microscopic characters of the ova have already been
described, and so need not be repeated here.
It is probable that each successive invasion of parasites, in other words,
each infected meal that the animal consumes, will be followed by a feverish
attack, and some temperature charts which I saw at Shillong, as well as one
supplied me by Dr. H. Hendley as illustrative of the outbreak of " Surra "
observed by him in Burma exhibit just such traces as one might expect
from a necessarily irregular cause of pyrexia such as this. In Dr. Hendley's
chart, reproduced below, dates of observation as to the presence or absence of
Trichominas Evansi are carefully noted ; but I confess I am unable to trace in
it any relationship whatever between the pyrexia and the presence or absence
of the nomads in question.
Taking the positive observations we find they are placed as below :—
1st Note. —Temperature nearly normal between two steep rises. Present for one
day .
2nd ,, At apex of a rise. Present two consecutive days.
3rd ,, Temperature fluctuating a little above the normal. Presenttwo con-
secutive days.
In nearly all the negative observations the temperature, as in the third
positive one, is fluctuating a little above the normal.
Such a trace might of course result from any irregularly acting cause of
pyrexia, and I merely draw attention to it in this connection with the view of
pointing out that, while the relationship between the course of the temperature
and the presence or absence of the trichomonads is by no means obvious, it is
in no way incompatible with what one may expect to find in sclerostomiasis.
In the chronic stage of the disease, i.e., after the parasites have effected a
lodgment, the main symptoms are loss of condition and marked anæmia, best
observable on the mucous surfaces of the tongue and conjunctiva.
In the last stages of the disease the temperature is often subnormal.
Assuming the diagnosis to be established, the obvious indication is to expel
the worms as quickly as possible ; but here my experiences are limited to a single
case. I can lay no claim whatever to any knowledge of veterinary medicine,
and hence I did not care to institute therapeutic experiments on animals
belonging to other folks.
It is quite obvious, however, on general considerations, that no remedy can
Temperature Chart of one of Dr. Hendley's cases of "Surra", in which the animal died on the 53rd day of the
disease, eighteen days after the last recorded observation of Trichomonads.
Medical Officers of the Army of India.
21
be expected to exercise any effect on the encysted worms, and hence, until they
return to the lumen of the intestine, all attempts at their expulsion must be hope-
less. So far as I know, we have no data at present at our disposal for esti-
mating the duration of the period of encystment ; but, practically speaking, worms
in both stages will be present in the majority of cases, and treatment must hence
resolve itself into the prevention of re-infection, combined with the periodical
administration of anthelmintics in order to expel any worms that may have
escaped from encystment before they have time to attain complete maturity, and
with it the habit of sucking their victim's blood.
In the case of my own pony I administered 1½ oz. thymol in three doses
of ½ oz. each, and the result, as I afterwards found, was to expel nearly every
free worm, Ova, however, soon re-appeared in the dung, and believing at the
time that this was due to inefficient action of the remedy, owing to its having
to reach the lower bowel before it could exercise its action on the worms, I
determined to make an attempt to introduce the remedy direct into the colon.
I accordingly made an emulsion of thymol by adding it, in spirituous solution,
to water, and injected it directly into the colon by means of an aspirator needle.
Further, suspecting the original dose might have been too small, I increased
the quantity to 2½ oz.
The animal seemed in no pain, and grazed naturally for some time after
the operation ; but within a few hours toxic symptoms appeared and the animal
died, the phenomena presenting a general resemblance to those of carbolic acid
poisoning.
Post mortem, it was only after considerable search that the puncture could
be found ; but it was quite obvious that the whole of the emulsion had passed into
the colon.
There was not the least sign of the characteristic smell of the drug to be
detected in the peritoneal cavity, and the neighbourhood of the puncture was quite
free from redness. In the bowel, enormous numbers of the worms were found in
the encysted stage, but only a very few free. There were, however, large
numbers of amphistomes, and all these, as well as the few sclerostomes present,
were dead for a considerable distance from the point of injection, as far, in fact,
as the remedy might be expected to be carried by peristalsis during the time
that had elapsed between administration and death. The fatal result was there-
fore clearly traceable to the largeness of the dose, and not to its method of
administration, and, in suitable doses, I still hope that the direct action of the
remedy so administered might be taken advantage of, though there can be no
absolute need of it, as the result showed that the original dose, administered by
the mouth, had acted quite efficiently ; and it seems to me that our best hope
lies in the repeated administration of this most catholic of all vermifuges, com-
bined with generally supporting treatment, and the administration of easily
digestible articles of diet.