34
Verminous Pneumonia in Animals in Bengal [VOL. XVIII, PART I,
Clinically, the disease was ushered in by an occasional dry and husky cough which generally
passed unnoticed till it gradually became more frequent. As the disease progressed, there was some
loss of condition accompanied by depressed appetite and irregular bowels. Later on, there was some
discharge from the nose, usually in the form of masses of mucus expelled during paroxysms of cough-
ing. In fatal cases, extensive involvement of the lungs became apparent and all the symptoms of
a true pneumonia developed, marked dyspnoea being prominent. In animals thus affected there
was a more or less complete loss of appetite, the rectal temperatures rose high, and many developed
diarrhoea. Once true pneumonia set in, death followed in a fortnight or so, though occasional
cases lingered somewhat longer. Recoveries were common only in those cases which did not show
signs of the lungs being involved to any 'considerable extent.
On post-mortem examination of a few carcases, the organs found mainly affected were the
gs. These commonly showed extensive consolidation accompanied by varying degrees of thicken-
and distension of the inter-lobular septa in parts. In some cases, there were either small dis-
e foci or bigger areas of suppuration. The basic morbid change uniformly present was an in-
titial cum catarrhal pneumonia, typical of verminous pneumonia. There was no evidence of
iritis. The trachea, and especially the bronchi, showed inflammatory and catarrhal changes
they always contained the worms, Dictyocaulus viviparus, generally in large numbers.
On microscopical examination, numerous typical metastrongyle eggs and larvae were seen
in fresh cover-glass preparations of lung exudate. Stained films of the exudate revealed a variety
of organisms among which chiefly two types predominated. In films made from the more or less uni-
formly consolidated non-suppurating parts, the predominant organism was a Gram-negative cocco-
bacillus having some tendency towards ' bipolar ' staining, while in those from suppurating parts
it was a Gram-positive diphtheroid. Due to lack of suitable facilities no cultural work could be
undertaken, so that it is not possible to state the exact identity of these organisms. It may be men-
tioned here, that in studies undertaken earlier by the author at the Indian Veterinary Research
Institute, Mukteswar, on the bacteriological flora of normal and pathological lungs of ruminants,
the two pathogenic organisms most commonly isolated were Corynebacterium pyogenes and those
known as ' haemolytic cocco-bacilli '. This is similar to the findings of other workers abroad [Bos-
worth and Lovell, 1944]. In view of this, it seems likely that these two were the organisms second-
arily concerned in this outbreak also.
Stained films of peripheral blood of affected animals and peripheral and heart blood of carcases
were uniformly negative. Histological examination confirmed the macroscopic and the micros-
copic findings. The basic picture was that of verminous pneumonia, but at many places this was
more or less completely masked by the superimposed bacterial pneumonia.
The results of these investigations left little doubt with regard to the correct nature of the
diagnosis. It was nevertheless considered desirable to examine the possibility of co-existing con-
tagious bovine pleuropneumonia. This was ruled out by the complete lack of reaction in two bulls
inoculated subcutaneously with lung exudate from a somewhat suspicious case.
The affection did not spread to the suckling calves and the few deaths which occurred among
them in this period were due to other causes.
LUNG-WORMS IN SHEEP
Dictyocaulus filaria and the pulmonary changes associated with it, i.e., typical verminous pneu-
monia, were often encountered in plains sheep in Calcutta slaughter-houses. Their occurrence
in hill sheep in Darjeeling slaughter-house was noted to be more common and the infested lungs
generally showed patchy consolidation, especially in the apical and cardiac lobes [Mohan, 1945].
Balwant Singh [1937] encountered Varestrongylus pneumonicus also in a few hill sheep.
Bengal is not a sheep-raising country and the occurrence of fatal outbreaks of pneumonia in
this species is not known.