MUKTESAR, FOR THE YEAR ENDING THE 31ST MARCH, 1931.
29
" Work on this was commenced on 15th July 1930, a sample of
blood from a case of P. gibsoni infection being obtained on this date
from the Jind State Kennels, at Bhim Tal. The total number of
subinoculations performed with this strain amounted to 18, the incuba-
tion period in the experimental animals ranging from 9 to 31 days
(average 14.6 days). The animals subinoculated were 16 dogs and 2
foxes; one of the latter, however, died shortly after receiving the viru-
lent blood. A noticeable feature of the disease in artificially infected
dogs was that the presence of the parasites in their circulation was not
associated with any elevation in their body temperature, although
immediately after the appearance of the parasites they went down
appreciably in condition, which, however, they regained a short time
afterwards. Thereafter the dogs apparently remained in good health,
in spite of the fact that the parasites, as also pronounced anaemic
changes, were noticeable in their blood for at least 6 months from the
date of the first appearance of the parasites. An interesting observation
in this connection was that six pups (two still-born) born of infected
parents showed rare P. gibsoni in their circulation immediately after
birth. The four surviving pups died within 3 days without showing
the organisms, but a dog inoculated with the heart blood of three of
these pups developed anaemic changes with the presence of P. gibsoni
in its blood. This part of the work was carried out by Mr. Krishna
Iyer."
" In connection with transmission experiments with Rhipicephalus
sanguineus, the preliminary work was directed to evolving a suitable
technique for feeding larval and nymphal ticks on dogs. Experience-
showed that the method as recommended by various workers, of libera-
ting the ticks in cages containing the experimental animals was not
suitable for feeding the larvae or the nymphs. An assortment of cup-
shaped receptacles was therefore tested as to their suitability for enclo-
sing the ticks over a limited area of the skin of the host by means of a
good adhesive, e.g. " Chatterton's compound", the procedure being
modified from day to day in the light of fresh experience."
(2) Canine Typhus.—The bacteriological study referred to in last
year's report was again continued by Mr. Mobbs. Further cases of
prolonged fever of undetermined origin were studied, and from one
of the dogs a culture closely allied to Bacillus dysenteriæ, Shiga, was
isolated post-mortem. The condition under study undoubtedly consists
of a number of different infections, and it will be a prolonged piece of
work to differentiate and diagnose them accurately.
(3) Spleen Extract treatment of Eczema.—Two cases of eczema
which occurred in experimental dogs at the Institute were treated by the
use of subcutaneous injections of a spleen extract, prepared and kindly
sent to us for trial by Major T. F. Arnold, R.A.V.C. Although cures
resulted, these cases did not respond to the treatment as quickly as had
been expected. Another case of persistent eczema with loss of hair of
the eyelid following conjunctivitis in a dog responded immediately to
the same treatment.