8
There is often much anæmic palpitation of the heart in the last stage, and the
membranes become blanched : some animals drop down and die suddenly, perhaps
when eating, others become delirious and struggle on the ground, while other
animals linger for days after they are helped up, but go on eating grass and corn
until they die.
Evans noted a certain amount of clear serum in the peritoneal cavity, but
no sign of any inflammatory action. In one case the pericardial sac was dis-
tended with fluid.
He says " that when he first saw the parasite, he thought for a moment, it
was some form of Spirillum, but rapidly changed his mind on that point. It
has an apparently round body when it is fresh and active, which tapers in front
forming a neck, ending in a blunt head, and behind it has a tapering tail from
which there extends a long slender lash, so fine that it can seldom be seen. It
had two fin-like papillæ on each side, one pair placed near the neck, and one
near the tail. He only occasionally saw the four at once, and they always ap-
peared to occupy the same relative positions.
He describes the parasite as being wonderfully active, and presenting un-
dulatory eel-like movements ; it has the power of altering its shape, progressing
almost always in the direction of the blunt end, though it is able to go in
the reverse manner when pulling a corpuscle. He examined the kidneys, liver,
spleen, heart, lungs, and the mucous lining of the stomach and intestines
throughout, with great care, and stated positively that this disease is not charac-
terized by any structural organic change ; it is purely a disease of the blood.
Petechias were noticed on the mucous lining of the intestines in some cases, but
in no case was the structure of the liver diseased. The disease is absolutely
fatal to horses, mules and camels.
There is no evidence to show that the disease is either contagious or infec-
tious in the ordinary sense ; the weight of evidence is to the contrary. Seventy-
seven horses of the 3rd Panjab Cavalry became affected at Jutta, and were
taken to Edwardabad and all died, but did not communicate the disease to others.
He considers that when horses are closely packed together, a large fly called
" Burradhang " may inoculate healthy animals with the blood of the diseased.
Evans submitted a puppy, inoculated with Surra parasites transferred from
the horse, to Dr. Lewis for his opinion. Lewis reported that " the parasites
appeared to be very closely allied to the flaggellated variety, which were detected
by himself in a considerable number of apparently healthy rats, but he could
not then venture to express an opinion as to whether they were specifically
identical."
Major Money, 4th Panjab Cavalry, stated that the disease was common
amongst the horses of the 3rd Panjab Cavalry when they obtained the grass
from inundated ground near the River Indus, but it ceased when they got grass
from higher ground. The outbreak takes place usually in August, but more in
September, and continues until January when it suddenly ceases.
Treatment.—The only form of treatment Evans tried was Carbolic Acid in
Glycerine (1 to 4), of which 219 drachms were administered during a period of
15 days, and still the organisms persisted in small numbers in the blood. The
dose was then increased to 3 oz. daily for a week, with no better result. He
tried with three other animals the same treatment, but they all succumbed.
* Steele, five years later, reported upon an outbreak in British Burmah.
The animals which he had to deal with, and which he made post-mortem
examinations on, were transport mules. He was much struck with the lesions
found in the stomach, so provisionally termed the disease Gastric-typhoid fever
of malarial origin ; at a later date, when he had made careful thermometric
observations, he came to the conclusion that the disease must be regarded as a
true relapsing fever, closely resembling relapsing fever in man, and was essen-
tially the same as the disease described in 1880 by Evans as " Surra,'' and only
* Steele, Veterinary Surgeon J. H., Army Veterinary Department, on his investigation into
an obscure and fatal disease amongst transport mules in British Burmah, 1885.