37
great, and correction of them will tend materially to prevention of its prevalence in
the future. It would be well worth the while of Government, in the event of future
outbreaks, to try the effects of change of climate by shipping affected mules in the
earliest stages of the disease to Bellary, Secunderabad, or some other dry place where
they could be kept isolated and treated under veterinary supervision.
36. I in one case removed blood from the heart of a mule just dead and which
I had an hour before ascertained to contain some parasites, and with it conveyed the
disease to another mule. The fact of the blood not having died before use lessens the
value of this experiment however. I have therefore inoculated with dried blood with
negative results; local abscesses, which healed readily, occurred at the seats of
inoculation. A safe practical conclusion to arrive at is that the carcasses of all animals
which die from this disease should be destroyed by cremation in their skins and without
post-mortem examination; except when necessary for scientific purposes; it should
never be needed to verify diagnosis. We are not assured that the flesh used as food
by dogs conveys the disease; vultures do not seem to suffer from it, but they may
distribute the spirilloids in their fasces.
PART III.—THE DISEASE.
The researches which have been carried out by myself supplement those of my
predecessors and place us in a position to give a systematic account of relapsing fever,
which must henceforth occupy no unimportant place in the list of equine diseases—
indeed of diseases in general, whether of man or animals. It specially demands
attention from veterinary officers serving in the East, and is very liable to occur under
the conditions of active service among animals of all the mounted branches. Its slow
insidious progress to sure fatality demands that we be jealously apprehensive of
its occurrence in a field force and constantly on the alert to avoid it or to detect it
in its earliest stages and manifestations.
2. The SYMPTOMS vary somewhat in accordance with the phase of the outbreak,
the individual peculiarities of the patient, the manner in which the attack has been
brought about, and possibly other conditions as yet ill-ascertained. In relapsing
fever, as in most other diseases of a specific nature, those cases which occur at the
commencement of an outbreak are generally the most acute and directly fatal, whereas
those which occur later often succumb finally to sequelae. This leads to correspond-
ing differences in the symptoms and post-mortem appearances, and accordingly the
phase of the outbreak is an important point to be noted in investigation and diagnosis.
Still throughout all phases of the outbreak we find attacks varying in acuteness and
urgency; this may generally to an extent be traced to some other disease affecting the
patient concurrently with the fever, to some defect of internal organs, or to still more
obscure conditions, as those of physique, digestive powers, and so on. The experi-
ments made by Dr. Evans with surra and by myself in this investigation have enabled
us to arrive at certain differences in the phenomena of the disease. in accordance with
species and the mode of entry of the materies morbi into the system. Yet with this
apparent difference in special cases there runs, as an under-current, the typical disease
which flows with definite course from commencement to close. There is always a
difficulty in determining when the attack actually begins except in experimental cases
from which we learn that the period of incubation in cases of inoculation of a
mule with large numbers of the parasites subcutaneously
injected is five days, in cases of administration as a drink
(gastric invasion) six days, calculating from the first abnormal
rise in the internal temperature, that is, the commencement of
the first fever exacerbation. We have ample evidence, there-
fore, that this disease may be induced artificially in 4—7 days.
The principal practical value of this fact lies in it affording us
some assistance in tracing particular cases home to their
immediate causes, but it is nevertheless diminished in value by the fact that it is a
matter of the greatest difficulty to decide when any particular case commenced. The
The disease manifested
itself earlier in my 'pony
case than in the mules, and
the period of incubation
was shortest of all in the
monkey; longest in the
dog, in which animal it
was only on 12th day the
parasites appeared in the
blood.
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