'Contagious Abortion. 427 



allowed to spread the infection through the bull that serves her 

 in common with other cows, and also by being sold into new and 

 healthy herds. 



Symptoms. Contagious abortion sometimes takes the form of 

 temporary sterility, the animal taking the male at frequent inter- 

 vals, but failing to conceive. If conception takes place, the 

 abortion is usually deferred until the foetus has attained a consid- 

 erable development — in cows till the third or seventh month ; in 

 mares till the fourth or ninth month ; in ewes or sows till the 

 tenth week. 



Often times premonitory symptoms are entirely unobserved. 

 Usually there may be detected some heat and enlargement of the 

 mammae, with a decrease in the milk-yield, or a serous modifica- 

 tion of the milk as in colostrum. Still more striking is a muco- 

 purulent discharge from the vulva — opaque, white or yellow — in 

 marked contrast with the perfectly clear, transparent mucus 

 which appears in oestrum. The discharge may be densely white 

 (in mares) or reddish, and may be accompanied by some swell- 

 ing of the vulva and redness of its mucosa, which is dull, rough 

 and granular, or even the seat of a papillary eruption. There is 

 rarely hyperthermia or other constitutional disturbance, and in 

 some cases the abortion is only discovered by the finding of the 

 foetus and its membranes in the gutter or pasture. The mem- 

 branes are, however, not unfrequently retained, becoming offen- 

 sively putrid. In other cases a muco-purulent discharge persists 

 for a length of time, insuring sterility so long as it lasts, and caus- 

 ing ill health and emaciation. The foetus is usually born dead. 



The Lesions are confined to the generative organs. Bang, 

 found an odorless, dirty yellow, flocculent, slimy and more or 

 less watery exudate between the chorion and uterine mucosa in- 

 volving the connective tissue between the chorion and arachnoid 

 so as to render it thick and friable. These conditions were well 

 marked in the French and English cases, and perhaps somewhat 

 less so in the American, which are habitually slower in reaching 

 the abortion. Bang found the uterine catarrh with the character- 

 istic bacillus in cases in which the calf had been carried to full 

 term, exemplifying the local presence and culture of the bacillus 

 without the usual abortion outcome. The bacilli were occasionally, 

 though not always, found in the body of the foetus, and in some 



