ABSTRACTS
The Etiology of Infections Diarrhœa (Winter scours) in cattle.—JOHNES, F. S.,
and LITTLE, Ralph B. Journ. Exp. Med. Vol. 53, June 1931, pp. 835-843.
In five dairy herds in which 400 cows were affected, an infectious diarrhœa known as Winter
dysentery of unknown etiology was observed. The chief symptoms noticed were watery fæces, deep
brown to blackish in colour, possessing fetid smell and containing blood and mucus in some cases.
The course of diarrhœa was from a few hours to 4 to 5 days but sometimes it recurred when the
recovered animals were allowed to have full diet. Fever was ordinarily absent although a few fatal
cases showed a temperature up to 40.2°C. The onset was sudden and the disease spread very rapidly
amongst adult cattle. Cows with a severe affection exhibited dullness, inappetance and abdominal
pain.
The chief anatomical changes were catarrhal inflammation of the small intestine (jejunum and
ileum) with swollen, wrinkled and congested mucosa. The liver was easily friable and pale yellow in
colour. The folds of the abomasum were congested and œdematous.
Calves fed with fæces or intestinal contents from sick animals contracted the disease and on
post mortem examination disclosed catarrhal enteritis. Cultures made from the intestinal lesions of
both the spontaneously and artificially infected cases revealed vibrios which, when fed to calves,
produced diarrhœa and well-marked enteritis, thus proving that they were the causative organism of
the disease. [ R. N. N.]
Vibrionic Enteritis in Calves.—JOHNES, F. S., and LITTLE, Ralph B. Jour.
Exp. Med. Vol. 53, June 1931, pp. 845-851.
In investigating the outbreaks of infectious diarrhœa amongst cows due to vibrios a similar
disease was discovered to be prevalent in many of the older calves in a large dairy herd, calves over two
weeks old being affected : they showed an unthrifty appearance and distended abdomen with their
tails and buttocks soiled with fæces, which were soft or gummy, nearly dark brown in colour and
contained blood and mucus. The disease was more evident during the winter, and as a rule it was
observed to be prevalent in a chronic form, although a few fatal acute cases were also noticed.
The anatomical changes were almost the same as found in infectious diarrhœa of adult cattle.
A transmission experiment of the disease was carried out by mixing three young vigorous calves
with a spontaneouly affected calf : two of them manifested distinct enteritis 10 days after exposure
to the infection and the third one showed only a slight gastric disorder. Cultures of vibrios obtained
from naturally affected cases produced enteritis when fed to calves, thus proving that vibrios were
the causal agent of the disease.
It is stated that the infection in calves ordinarily takes place relatively early in life, manifesting
at first mild symptoms of the disease which become aggravated as the disease progresses towards the
chronic stage. [ R. N. N.]
The use of drugs in the treatment of disease caused by Nematode and Trematode
worm. TAYLOR, E. L. (1930).—11th Int. Vet. Congr., 3, 273-286.
To determine the comparative anthelmintic efficacy of a drug, the best is Hall's method, viz. : to
kill the test animal after the treatment and compare the number of worms left behind with those that
have been actually expelled.
To associate the anthelmintic efficacy of a drug with a particular part of its molecular structure,
e.g., halogen component in CCl 4 , has led to the discovery of many valuable drugs.
The action of anthelmintics being specific, the exact nature of the infection should be determined
before the commencement of the treatment and also the intensity of infection.
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