V. R. GOPALAKRISHNAN
291
Characteristic lesions are noticed in the thoracic
cavity. It contains a large quantity—about
half to three litres or even more of straw-coloured,
clear, serous fluid, which coagulates quickly.
Sometimes strands of yellow fibrinous membrane,
soft and spongy in consistency, are also noticed
in the pleuritic effusion. The pleura appears
congested and somewhat thickened, with a large
quantity of fibrinous deposit; and usually there
are adhesions between the parietal and visceral
pleurae. One or both the lungs are affected.
The dorsal surface of the lungs is more or less
firmly attached to the chest wall by the dense
fibrinous adhesions. Fibrinous deposits are not
only found on the pleura and on the adherent
surface of the lung but also sometimes on the
diaphragm. The lungs are much enlarged,
firm, heavy, almost completely consolidated and
pieces sink in water. The cut surface presents
a typical ' marbled ' appearance, from which
exudes almost clear straw-coloured fluid. The
exudate is sometimes blood-tinged and readily
coagulates. On careful examination of the in-
cised portions, all the phases of fibrinous pneumo-
nia from the initial congestion to red and grey"
hepatization could be seen.
Oedema of the alveoli and of the interlobular
septa is observed. Oedematous infiltration of the
interlobular connective tissue and thrombus
formation in the blood vessels are also noticed.
A few petechiae and a little fibrinous deposit
are seen on the pericardial sac which contains
about 25 to 100 c.c. of clear, slightly yellowish,
serous fluid. The lymph glands (broncho-medi-
diastinal and deep cervical) are enlarged, oedema-
tous and congested. No sequestrum formation
nor any specific lesion elsewhere, particularly
in joints, could be observed.
TRANSMISSION EXPERIMENTS
Experiments were undertaken at Gauhati,
with a view to observing whether the disease can
be artificially transmitted to healthy animals.
(a) Transmission experiments in bulls were
carried out twice; on the first occasion with the
fresh material obtained from Deosiri area and on
the second occasion with material from Pata-
katchar. Five c.c. of a mixture of penumonic
lung emulsion and pleuritic effusion were inoculat-
ed subcutaneously to two healthy bull calves.
Also about 5 c.c. of the emulsion was administered
intranasally to one of the bull calves in addition
to inoculation.
REACTION
There was a rise of temperature on the ninth and
tenth day, ranging from 104.8° to 105.8°F.,
followed by a gradual fall to the normal in the
course of a week. Dullness, dry muffle, inappe-
tance, occasional cough and a little watery dis-
charge from nose were observed. Slight involve-
ment of the lung, as manifested by percussion,
was evident on the tenth day, but later improve-
ment was noticed synchronizing with the fall in
temperature to the normal. At first the swelling
at the seat of inoculation was hot, painful and
oedematous. Later it increased in size and ex-
tended further, involving the neighbouring tissues
and was hard and painful with no indication of
abscess formation. The process was characteris-
tic in that the earlier affected part remained hard
and the freshly affected one oedematous. One
calf died on the 18th day, and the other on the
20th day.
Post mortem lesions were not prominent in the
lungs, while the lesions at the seat of inoculation
were extensive—hard swelling extending over the
entire shoulder and adjoining parts, the cut sur-
face was reddish-yellow in colour, hard and firm
in consistency; no exudate or pus could be
noticed except in the periphery where the swelling
was oedematous with pronounced serous infiltra-
tion of the subcutaneous and intramuscular con-
nective tissue. The absence of lung lesions in
the experimental animals was worthy of note.
The gross involvement of the connective tissue
with serous infiltration and the tendency towards
a chronic productive inflammation suggest the
similarity of the pathological process due to the
infective agent in the lung as well as in the
muscle. This indicates the specificity of the
infective agent and also the possibility of experi-
mental reproduction. In an experimental study
of the histopathological changes brought about
by intramuscular injection of calves with the
virus of contagious pleuropneumonia, Boynton
[1912] observes that the muscle lesions correspond
with the lung lesions in practically every respect.
The main identical features are the specific action
on the connective tissue elements, sero-fibrinous
exudation, thrombus formation and a tendency
towards a chronic productive inflammation.
(b) A healthy goat was inoculated subcuta-
neously with 5 c.c. lung emulsion and pleuritic
effusion. The goat was under observation for
one month. There was slight local swelling with
a little oedema for three days, and subsequently
it disappeared. Temperature did not show any
marked variation, nor there was any difference
in appetite. The goat appeared normal and heal-
thy and was discontinued after a month.
(c) Fresh material consisting of lung emulsion
and pleuritic effusion was sprayed into the
nostrils of two goats. They did not show any
sign of illness during the period of observation
extending up to three weeks.