STATE HYGIENE 617 



The abortion bacillus may retain its vitality for some 

 time outside the body, a point of great practical importance 

 in dealing with the question of disinfection, and the disposal 

 of abortions and excreta from affected animals. 



Epizootic abortion in the mare is not so common as in 

 the cow, but is attended by much greater risk and severe 

 constitutional symptoms. Besides metritis, pneumonia 

 and laminitis are common in this disease. The affection 

 may be introduced into a stud by mares which have recently 

 aborted, and no doubt also from mare to mare, as from 

 cow to cow, by infection carried by attendants. The period 

 of incubation is also shorter in the mare than in the cow, in 

 which latter it may, as the results of experimental inquiry, 

 be as long as two months, or even longer. 



McFadyean in the paper previously quoted, the substance 

 of which we are here giving, draws attention to the fact 

 that in the ewe abortion generally occurs within a week of 

 full term, from which he supposes that the poison affecting 

 the cow can hardly be the same in the ewe, or abortion 

 would occur as in the other animals at any period of the 

 pregnancy. Bang's experiments, however, show that the 

 poison of the cow can produce abortion in the ewe, though 

 as McFadyean expresses it, it cannot be positively stated 

 that a contagious form of abortion does occur in sheep. 



The prevention of abortion is a most important matter, 

 and the subject may be divided under two heads, viz., the 

 best method of preventing the introduction of infection into 

 a herd or stud, and how to prevent its spread if once intro- 

 duced. 



The renewal of dairy stock from time to time is a most 

 fruitful source of introducing the disease. A cow may be 

 infected and give no sign of ill-health, even carry her calf 

 to full term, and yet be the means of introducing disease. 

 The isolation of new purchases is not, therefore, a very 

 promising preventive. The risk of introducing disease is 

 less with heifers than with cows, but the only real safe- 

 guard is to purchase in those quarters where there is 

 complete assurance the disease has not existed. 



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