280 THE INDIAN JOURNAL OF VETERINARY SCIENCE AND ANIMAL HUSBANDRY [ IV, III

Of 11 unvaccinated controls exposed, 10 (91 per cent.) died of rabies.

Since the report was made, the remainder of 40 vaccinated dogs and additional
controls were exposed, and the final summary of the results of dogs treated
with carbolized vaccine is presented in Table I.

                                        DISCUSSION.

The results of our studies, in the use of the single-dose carbolized canine
rabies vaccine, indicated that none of the vaccines used were capable of immuni-
zing dogs against any of the viruses used.

There was some indication that the injection of street virus did not immunize
dogs against a subsequent injection, 60 or more days later, of either the same
strain or a different strain of virus.

The single-injection method of vaccinating dogs with carbolized vaccine is appa-
rently unreliable and does not immunize dogs against rabies, and, therefore, should
not be relied upon as a means of controlling rabies in dogs.

                         CHLOROFORM-TREATED VACCINE.

After the first experiments in the use of carbolized vaccines were nearing com-
pletion, another group of healthy dogs was inoculated by different channels—sub
arachnoid intramuscular and intravenous—with various dilutions and various-sized
doses of rabies virus to determine, if possible, the comparative minimum fatal dose
and to form a better basis for exposing dogs after vaccination with a chloroform
treated vaccine. In these tests, only one virus (27039) was used and dilutions were
made so that 0.5 c.c. represented the dose in each case, Emulsions ranging from
10.0 per cent. down to 0.009 per cent. were used, and the 0.5 c.c. dose contained
amounts of brain material ranging from 0.8 grains (50 mg.) down to approximately
0.0007 grains (0.05 mg.). The results were somewhat irregular but there seemed
to be some indication, within certain limits, that the dispersion of virus by dilution,
rather than the amount of virus, had some relation to infections which took place.

On August 20, 1931, 20 healthy dogs were vaccinated with commercial
(Laboratory A) chloroform-treated rabies vaccine prepared by the Kelser method.
An equal number of dogs were set aside as controls. These groups were sub-divi-
ded and, later, individual dogs or groups were exposed through different channels
to different strains of virus as is shown in the accompanying tables.