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OBSERVATIONS.
In this first volume of the Surra Report, it is impossible to discuss satis-
factorily the whole subject of the disease, owing to the large number of side
issues affecting it, and to the fact, that in Volume II the Idiopathic disease as
it occurs in rats, dogs, and other animals than horses, has to be treated and dis-
cussed, as well as the presence of the Infusorian in certain kinds of fish.
The localities, in which the disease occurs, are found generally within a belt,
bordered by the 18° and 24° of N. Latitude and are of two kinds : first, those in
which the disease is known to be endemic, and second, those in which it has
occurred either at intervals of some years, or on one known occasion only. The
former are damp and low-lying, possessing a warm, humid and equable climate,
exceedingly favourable for the development of Infusorial life ; the latter are also
low-lying, but have a climate almost exactly opposite to the other, viz.,. a dry
atmosphere for many months of the year, a considerable variation of temperature,
and a comparatively small rainfall. The rivers, however, in the latter localities
are liable to inundate the surrounding district, and thus contaminate with the
Infusorian the herbage employed for feeding purposes.
The main point ascertained in this enquiry is, that the Infusorian of Surra
can in the first place be made to disappear from the blood of affected animals,
by subjecting the latter to a short course of treatment with Arsenic ; and, by
a more prolonged administration of the chemical, it can be completely destroyed ;
but the extent to which the Arsenic could be administered without injury to the
animal is as yet unknown.
It is therefore of importance to large horse-owners to consider whether
certain preventive steps should not be adopted previous to, and during the period
in which outbreaks are usually known to occur, instead of treating the disease
on its appearance; and this may be considered under two distinct heads, viz. :—
(a) The destruction of the organism in the food and water ;
(b) The prevention of its development, by the administration of Arsenic
to animals inhabiting an endemic area.
In the first case, the method to be suggested would be the exposure of the
organism for a brief period to the temperature of 212° F. This could be attained
by boiling all the water employed for drinking purposes, and by submitting the
food (corn and fodder) to the action of steam in specially constructed chambers.
The adoption of this process should not entail a great outlay where there is
steam already available, and certain advantages would accrue besides the complete
destruction of the Surra organism, viz. an improved digestibility of the corn and
dry fodder, by which less would be required to keep the animals in good working
condition ; and the destruction of any injurious fungoid growths in musty or
badly prepared hay.
In the second case, Arsenic would have to be administered in small, but
gradually increasing doses for from two to three weeks at a time, with intervals
of about the same period. The administration would have to commence at the
end of the dry season, and be continued with the above intervals until the end
of the rains.
The whole question, however, hinges upon whether the loss of animals from
the disease is worth the expense and trouble entailed, by the adoption of either
or both the above processes. To be of any service they would have to be carried
out in a thorough manner for a long period, and the animals subjected to
arsenical treatment would probably undergo a certain amount of depreciation in
value.
B 1086 – 32