Scientific Memoirs by
inoculated a dog on 20th September 1886 and on 24th found many parasites in
its blood ; the animal after that date, for a period not stated, continued playful
and healthy-looking, nose cold, but yet the blood was " crowded more or less
with the special organisms more or less numerous as indicated by the internal
temperature "—this observer inferring that an " animal may be apparently quite
healthy and yet have the disease in his system." Adverting, lastly, to the
more precise experiment of Mr. Steel, there is the chart and history of a young
dog inoculated and given tainted mule's flesh to eat on 13th January 1881 :
blood-parasite first seen on the 24th, and on 28th animal dull, had slight cough,
and exhibited pain when pressed on the loins—she was very feverish while the
blood contained parasites, and the conjunctivæ became pale in the extreme ; she
was allowed to eat portions of all the mules which died, but her appetite became
very capricious—On 25th February the animal was found very dull, feverish and
thin, with a swelling on each side of the head—also the left inguinal glands
swollen, and the body in general so tender that the animal shrieked when lifted
from the ground ; in the blood no parasite seen, but many disintegrated corpus-
cles : the glandular swellings increased, and then soon appeared œdema of the
perineum, turgescence of the throat and muzzle, extreme prostration, swelling of
the hind quarters, coldness of the body, and death on 4th March (fifty-one days
after first inoculation) ; the chart given showing, first, a series of 6 or 7 distinct
febrile exacerbations of 3—5 days' duration and separated by brief apyretic in
tervals of 2—4 days' duration, but afterwards displaying more irregularities with
days of great depression of temperature. Upon enquiry of Mr. Steel, I learn
his opinion that here as in the monkey (which died with similar sequelar signs
of septic infection) the later illness was really part of the " surra " disease pure
and simple ; autopsy of the dog was made too late to be of real value.
According to the above comparative data, the " surra" infection like the
"spirillar " is readily implanted in the monkey, whilst retaining much of its
superior gravity : both instances, however, showing a certain diminution of degree
in this transfer. As regards the dog, in which the spirillar contagion is wholly
inefficacious, if the first-named results be regarded apart, the case becomes
analogous to that of my experimental monkey inoculated with the rat's organism,
in so far as showing that the mere presence of the active monads did not induce
palpable morbid signs ; but the last result indicates, at least, that before decid-
ing on the real effect of the " surra" inoculation precise and prolonged observa-
tions should be made. Viewing the whole series together, it seems legitimate to
infer that the surra-infection admits of considerably wide limits of intensity, and
this independently of the visible quantity of organisms, so far as may be judged
from statements of observers : being in some instances (as in equines) almost
inevitably fatal, in others (as in the monkey) less immediately so, and, lastly,
in the dog not necessarily occasioning early serious illness.
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