A PRELIMINARY NOTE ON VACCINATION AGAINST BOVINE CONTAGIOUS
PLEUROPNEUMONIA IN ASSAM*
By V. R. GOPALAKRISHNAN, Veterinary Investigation Officer, Assam
(Received for publication on 10th April 1946)
I N a previous article [Gopalakrishnan, 1943] an account was given of the occurrence of bovine
contagious pleuropneumonia in Assam, as a specific epizootic with a tendency to spread in a
slow and insidious manner. The high rate of mortality, ranking almost next to that of rinderpest,
was recorded and the necessity for taking effective control measures was emphasized. The im-
portance of vaccination in the control of the disease was also indicated. In the present paper an
attempt is made to give the details of the preliminary field trials with contagious pleuropneumonia
vaccine prepared at the Imperial Veterinary Research Institute, Izatnagar. The product used
was a culture-virus-vaccine tested by tail tip inoculation (Willem's method).
EXPERIMENTAL VACCINATION
Arrangement was made to stage a field test of pleuropneumonia vaccine at Gauhati. Five
local indigenous cattle—two calves, a cow and two bullocks were inoculated on 12th January 1943
with 0.5 c.c. of pleuropneumonia vaccine subcutaneously, one inch from the tip of the tail. The
vaccine was an eighth passage living culture of the Assam pleuropneumonia organism in Benett's
broth already tested for purity and safety at the Imperial Veterinary Research Institute, Izatnagar.
Reaction. There was slight swelling or thickening of the tail at the site of inoculation from
the 2nd day. It was a little tense, hard, painful and it was difficult to bend that part of the tail.
The swelling gradually subsided in eight to ten days and very little was left after a fortnight. In
no case was any weakness or injury of the tail noticed. Normal temperature was maintained through-
out the period excepting a little rise from the 3rd or 4th to 7th or 8th day. The general condition
was satisfactory and they were feeding well. The reaction appeared satisfactory.
FIELD VACCINATION
Vaccination was undertaken in Kukuria village in Kamrup district. The locality chosen for
the field test was a known enzootic area on the southern bank of the Brahmaputra. In Kukuria,
167 cattle were vaccinated on the 27th and 28th February 1943. Calves under six months and old
animals were not inoculated.
Reaction. The reaction was almost similar to that observed in the field test. There was slight
local swelling in the tail, otherwise the animals appeared normal and to feed as usual. The vacci-
nated cattle were used for field work with no apparent ill-effect.
Periodical observations were continued for over a year and the vaccinated cattle appeared
normal. There was no report of the occurrence of bovine contagious pleuropneumonia in the village
or in its neighbourhood.
IMMUNITY TEST
The five cattle vaccinated at Gauhati were kept under observation and maintained for immunity
test with fresh field virus.
In November 1944, an outbreak of bovine contagious pleuropneumonia was investigated in
Jaobari village in Darrang district. Fresh material was collected from a heifer that showed typical
symptoms and characteristic post-mortem lesions. A portion of the material was sent to the Im-
perial Veterinary Research Institute, Izatnagar, on the 24th November 1944 and the rest was used
for the immunity test at Gauhati. It may be mentioned here that a report was received from the
Institute stating that the fresh material was inoculated in two hill bulls and typical pleuropneumonia
lesions developed from which the virus was obtained. It was also reported that histological exami-
nation of the material showed lesions typical of contagious pleuropneumonia.
* Paper read at the Indian Science Congress, Medical and Veterinary Sciences Section, Bangalore, January 1946
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