SOME OBSERVATIONS OF PASTEURELLOSIS
I.—AN OUTBREAK OF PASTEURELLOSIS IN GEESE
By R. N. MOHAN, Veterinary Investigation Officer and S. K. BHADURY, B.Sc., Assistant Veterinary
Investigation Officer (Poultry), Bengal
(Received for publication on 12 June 1946)
R ECORDS of the incidence of pasteurellosis in birds in India are limited to fowls and the occur-
rence of natural outbreaks of the disease in geese and other poultry have received little atten-
tion. In this paper is recorded, presumably for the first time in this country, an outbreak of ' fowl
cholera' in geese. The diagnosis was made by microscopical and cultural examination. Some
pathogenicity tests were also done.
HISTORY OF THE OUTBREAK
Geese were purchased periodically from different places in the mofussil and stocked near Calcutta
for sale in the city and elsewhere. At the time of investigation, 6th December, 1945, there were
1325 geese and a few ducks. These were accommodated under most unhygienic conditions on an
area measuring about one-quarter of an acre, which included a small pond, so that there was con-
siderable over-crowding.
Sporadic deaths were more or less a regular feature, but after the middle of November, 1945
the geese started dying in increasing numbers. Thus, during the 12 days preceding investiga-
tion, some 160 geese died, 24 deaths being reported on the last day.
Only one duck died late during the period of investigation. This too was diagnosed as pasteu-
rellosis on blood-film examination.
INVESTIGATION
Microscopical examination of blood-films and post-mortem examination of one goose cadaver
received with the mortality report on the 6th December, led to the diagnosis of pasteurellosis. This
was confirmed on further investigation, the results of which are given below.
Microscopical examination. Films from peripheral and heart blood, and also from liver and
spleen, of several cadavers constantly revealed ' bipolar ' organisms, typical of Pasteurella aviseptica,
which were generally present in large numbers. In some cases, even in Leishman-stained films,
there were distinct indications of the presence of capsules manifested by a clear halo around the
organisms, in contrast with other post-mortem invaders which sometimes gained access in small
numbers.
Cultural examination. From heart blood and liver of two cadavers Pasteurella aviseptica was
isolated in pure or almost pure cultures. Morphologically, they were Gram-negative short rods and
ovals. Their other cultural and biochemical characters were : non-motile ; small, low convex,
round, transluscent, butyrous colonies on agar plates; fairly good growth with incomplete surface
pellicle, turbidity and viscous sediment in broth ; moderate growth on agar slope; good growth on
blood-agar; no haemolysis; no growth on McConkey ; no change in litmus-milk; indole strongly
positive; acid, no gas, in sucrose, mannitol and maltose, but not in lactose,
Pathogenicity tests. Rabbits, guinea-pigs and fowls were available for inoculation. These were
used as follows:
About 2 c.c. of heart blood from a goose cadaver was mixed with about 5 c.c. of sterile broth.
Of this about 3 c.c. was inoculated subcutaneously into a rabbit and about 2 c.c. intraperitoneally
into a guinea-pig. Both died the following night and films from peripheral blood and internal
organs showed typical Pasteurella.
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