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Bovine on Pleuropneumonia
One animal recovered from the reaction and one failed to react, thus giving a positive reaction
of 96 per cent and a mortality rate of 92 per cent. The reaction was as in cattle tested with the
two strains of Assam virus.
(b) Indian buffalo. One buffalo inoculated subcutaneously with 2 c.c. fresh Assam 1 lymph
virus showed no reaction over a period of six months. A second buffalo similarly inoculated with
5 c.c. virus developed a typical local and thermal reaction, the former of 31 and the latter of 14 days'
duration. The swelling ultimately softened and ruptured, and the animal recovered.
Goats
A considerable number of goats has been tested with Assam virus and the reaction is practically
constant. Twenty four to forty eight hours after inoculation at the side of the neck with 2-5 c.c.
Assam lymph virus, local inflammatory œdema is seen and this spreads to the entire neck and the
prescapular glands. At about the 5th-6th day, inflammation abates and induration of the neck
muscles progresses. The temperature reaction is rather erratic and in most, it is similar to that
observed in cattle. In no case has systemic disturbance been noted, and no deaths have resulted.
Sheep
Four sheep were subcuteneously inoculated with 2 c.c. fresh Assam 1 virus. Sheep 1 developed
a local and thermal reaction and died of rinderpest 7 days post inoculation Sheep 2 died of parasitic
penumonia 24 days post inoculation Sheep 3 showed a local and thermal reaction commencing on the
5th day post inoculation and attaining a maximum 8 days later. The circumscribed lemon sized
local lesion slowly subsided, disappearing by the 23rd day post inoculation Sheep 4 failed to react.
Laboratory animals
Of three rabbits and three guinea pigs inoculated subcutaneously with 0.25 c.c. Assam 1 lymph
virus, one rabbit died within 24 hours of acute pasteurellosis and no reaction was noted in the other
test animals over a period of two weeks. The experiment was repeated and all six animals died
of acute pasteurellosis. Three rabbits and three guinea pigs did not react to the subcutaneous
inoculation of Australian 264 virus. Three rats were subcutaneously inoculated with 0.5 c.c. Assam
1 virus and three with the same dose of Australian 264 virus. No reaction occurred in any animal
over a period of fourteen days. This experiment was repeated in mice at a dose rate of 0.25 c.c.:
one mouse died of acute pasteurellosis and no reaction was observed in the remainder for the same
period of observation.
PATHOLOGY
The lesions of the disease in Assam conform to type. The thoracic cavity contains a varying
quantity of a clear, amber-coloured exudate, rich in fibrinous flocculi and clotting rapidly when the
chest is opened. The pleurae are inflamed and covered with a layer of organising fibrin with frequent
adhesions of the lung to the chest wall and pericardium. The mediastinum is oedematous and the
associated glands enlarged and juicy, but free from haemorrhages. Pneumonia is usually unilateral,
the right lung being more commonly affected, especially the middle lobe. Fibrinous pericarditis
with exudation is frequent. The cut surface of the lung is 'marbled' owing to distension of the
interlobular septa with exudate and the lobules show variegation; some thrombosis of the lymph
channels and branches of the pulmonary artery is always evident. Ischaemic areas have been noted,
but never sequestrum formation.
We agree with Zeigler [1921], Mayer [1909] and other workers that the histological changes in
the lung are characteristic and that a histological diagnosis of the disease is possible. We have
compared the lesions of the Assam disease with lesions in section material obtained from South Africa,
Kenya and Australia and confirm their identity. There are three findings considered to be of some
interest. (1) In our opinion, the organism cannot be demonstrated in lung sections by any known
staining method. We have attempted the method originally described by Turner et al [1935], Giemsa
and many of the modifications of this method, Haidenhain and other hæmatoxylin methods, modified
acid fast stains and also silver impregnation methods, all without success. By certain of these methods