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THE INDIAN JOURNAL OF VETERINARY SCIENCE AND ANIMAL HUSBANDRY [VII, IV
reaction soon after the introduction of the drug, in the form of foaming at the mouth
and shivering lasting for about two hours; inappetence, rise in the body tem-
perature lasting forty-eight hours ; and a painful local swelling which persisted for
a week. The day following, however, the parasites were not detected in blood
smears from Hill bull No. 246, while the animal was under observation. In view
of the toxic effects of 10 c.c. of ' Akiron R ', the dose was reduced to 5 c.c. in the
remaining animals. Of the four treated animals shown in Table II-A, with 5 c.c.
doses, two were injected sub-cutaneously and the other two intramuscularly, on
the day the parasites were detected in their blood smears. These four animals
also showed a mild reaction to the drug, but none of them revealed the presence of
B. bigemina during a period of observation of ten days.
Being encouraged by this finding more extensive trials were undertaken as
indicated in Table II-B. In this series, the multiplication of the parasites was
allowed to progress to various degrees, before treatment was given. Ten bulls
were treated in different stages of the disease, leaving eleven animals to serve as
controls. It would appear that in all the treated cases the peripheral circulation
was cleansed of the parasites within forty-eight hours and no evidence of any
relapse was confirmed by daily microscopical examination of blood films for the
following ten days. In the controls, however, the parasites persisted. The drug
appeared to become absorbed quickly and in the case of Hill bull No. 686, from
which smears were examined every hour, it was noticed that a large number of
parasites were distorted and commencing to disintegrate five hours after the
injection. Whether the drug exerts a destructive action on the chromatin or
the cytoplasm or both could not be definitely determined; for, both these
structures, as noticed in the stained smears, were affected, leaving an irregular
mass of the remnant on the erythrocytes. The destroyed parasites were then
found to be gradually disappearing. At first the nucleus appeared as a speck of
pink colour surrounded by a distorted, shrunk and deeply coloured cytoplasm.
Later, in place of the nucleus, a small vacuole appeared within a dark mass of
cytoplasm. This could then be easily mistaken for an artefact.
The curative effect of ' Akiron R ' for B. bigemina infection, as would appear
from the foregoing experiments proved to be far superior to that of trypanblue,
for, a complete sterilization of the peripheral circulation was obtained within a
short period. It will be observed that in most of the treated cases the dose of
5 c.c. of the drug produced a certain amount of reaction, and on this account, it
was considered that a smaller dose may possibly yield identical results with advan-
tage. The subsequent series of experiments were, therefore, directed towards the
determination of a minimum effective dose of ' Akiron R '. Four trials were
carried out as tabulated below (Table III), to test the efficacy of 1 c.c. on an
average body-weight of 100 kg.
The microscopical examination of blood
films of such cases, however, showed that the reproduction of the parasites pro-
gressed unabated, proving thereby that this was too small a dose to effect a cure.