Moussu has seen several animals suffering from metritis, and even from salpingitis, recover spontaneously after six to eight months at grass.
EPIZOOTIC ABORTION IN COWS.
This disease, which was carefully investigated, first by Professor Nocard of Alfort, and afterwards by Professor Bang of Copenhagen, may be regarded as a specific uterine catarrh, determined by a definite species of bacterium.
It often affects large numbers of animals in one district or on one farm, and causes very serious loss. It is conveyed from cow to cow either by the bull or by litter or utensils used in the byre which have been soiled by the uterine discharges of an infected cow. As in many other infectious disorders, one attack of the disease seems to confer a certain immunity, and although some cows become sterile after an attack and others continue to abort, a certain proportion after aborting two or three times acquire relative immunity, so that they conceive and carry their calves the full time. This is probably why epizootic abortion usually ceases after some years in herds which are kept isolated and do not receive fresh recruits.
The microbe of epizootic abortion is a very small bacterium which stains well with Löffler’s methylene blue. When massed together these bacteria resemble cocci, but isolated specimens are seen to be true bacteria containing one, two, or occasionally three roundish, elongated deeply-stained granules. They do not stain with Gram, and are non-motile.
These bacteria exhibit remarkable vitality. Bang relates cases which seem to prove that they may exist within the uterus for at least fourteen months, and in the uterine exudate outside the body for at least seven months, even at comparatively low temperatures.
On post-mortem examination one finds between the mucous membrane of the uterus and the fœtal envelopes an abundant odourless exudate, dirty-yellow in colour, somewhat thin, pultaceous, slimy, or lumpy in character. Under the chorion is found a thin, clear, gelatinous substance contained within the fine connective tissue lying between the chorion and allantois. The umbilical cord is often œdematous. All these exudates contain the specific minute bacterium.
The above exudate forms the peculiar dirty, reddish yellow, slimy, flocculent, pus-like odourless fluid which escapes from the vagina during or immediately after the act of abortion.
The results of infection of the uterus with Bang’s bacterium may be delayed for a considerable time. In two cases where he injected pure cultures into the vaginæ of pregnant cows no apparent local results had been produced at the end of thirty-three and thirty-five days respectively when the cows were slaughtered; but in the case of two other pregnant cows, inoculated three months after conception, signs of abortion became apparent, and one cow in fact aborted in about ten weeks; post-mortem examination revealed the characteristic local changes, and microscopical and cultural preparations clearly established the presence of the specific organism.
Although the sexual organs form the usual channel of infection, it seems possible that the organism may in some cases enter the body through the respiratory or digestive tract.