4
even the camelman will recognise that his animal is sick in this stage, as it
does not graze well. But if the camel survives the first year the fever
paroxysms becomes less severe and he often grazes fairly well in the height
of one, although he has lost much in condition. These are the cases which
camelmen not unnaturally consider as merely suffering from the debility
caused by last year's sickness which they think has passed. I endeavoured
to impress the fact that these survivors with a history of sickness in the
previous year are still suffering from a low fever and are still a source of
danger to other camels with which they may be grazed in the Surra season.
18. During this tour, Hippobosca Camelina was met with from Lalgarh
to Rojhan. This fly is not found in the Punjab east of the Indus, nor in
Bikanir State. Like all Hippoboscae it sticks to its host with great per-
sistence and has therefore no probable importance in the transmission of Surra
among camels.
EXPERIMENTS ON TREATMENT OF SURRA IN CAMELS.
19. At the time of my last report the following facts had been arrived
at regarding drug-treatment by Arsenical and Antimony compounds :—
Drugs capable of use in dispersing trypanosomes were Atoxyl (intra-
venously), Soamin (subcutaneously or intravenously), Tartar emetic (intra-
venously), and certain Arsenical solutions given per os, namely Sodium
Arsenite, Sodium Arsenate, Liquor Arsenicalis and Donovan's solution, among
which Sodium Arsenate was considered the best.
20. Among Drugs which were found useless for the purpose when given
in bolus were yellow Orpiment, Antimony Sulphide, and white Arsenic.
21. Of the useful drugs, several combinations had been tried, and al-
though no cure had been obtained, the results of a treatment by Atoxyl
(intravenously), Tartar emetic (intravenously) and Sodium Arsenate solu-
tion (per os) were considered promising as the return of trypanosomes after
the last dose did not take place until 44 to 58 days had elapsed.
22. During the year now under report, this combination of drugs has been
chiefly worked at, altering the intervals and doses, and the methods of ad-
ministration, until the amounts of each drug that the camel can stand given
in these various ways is now pretty well defined, and it seems as though cures
have been obtained.
Regarding statements about apparent cures of Surra in camels caution is
necessary owing to the peculiar characters of the disease in these animals.
Thus cases of spontaneous recovery occur after suffering from the disease for
several years, and are fairly frequent in camels carefully looked after by
their owners ; these recovering cases are recognisable by the mild paroxysms and
the greatly increased intervals between these paroxysms.
For purposes of experimental drug-treatment one has to eliminate such
cases as unfit and likely to yield doubtful results ; and when a camel intended
for experiment is not obviously in the acute stages of the disease, it is necessary
to subject him to daily examination of blood for some time prior to treatment
to make sure that he is a suitable subject.
This has been done in the cases I am about to mention. (Complications
rendering the animals useless for experiment are very frequent, particularly
lung-abscess, and sometimes dilatation of heart ; whilst other camels arrive
in such wretched condition as to be quite unable to stand any treatment by
Arsenic. Altogether, only about half the camels received are fit for experi-
mental treatment.)
But the chief difficulty is to decide how long one must examine the blood
in apparently successful drug-cures before one can definitely state that the
camel is really cured.
I have had an acute case of Surra which relapsed 87 days after the
last dose and another which relapsed in 58 days. Considering the circum-
stances, the view I take is that if a number of camels treated by one experi-
mental method not too dangerous were to go six months under daily blood
examination without relapse, it would be good enough to recommend for
trial in Camel Corps ; if besides this some had gone 15 or 18 months without
relapse, it would give additional confidence.