376 The Diseases of Animals 



CONTAGIOUS ABORTION 



Contagious abortion is most common in cows, 

 although it sometimes occurs among mares, when large 

 numbers are kept together, as on some of the ranges 

 of the West. In some dairy regions, contagious abor- 

 tion is one of the most serious diseases that dairymen 

 have to contend with. ' After the disease is once estab- 

 lished in a locality, it is difficult to eradicate it entirely. 



The cause of contagious abortion is believed to be 

 a germ, or perhaps several kinds of germs. The dis- 

 ease is transmitted from an animal that has aborted 

 to a pregnant animal, by means of discharges from the 

 vagina or by the foetal calf or the membranes. It 

 seems probable that the disease can be communicated 

 by a bull that has served a cow that has aborted. 



Cows may abort at any stage of pregnancy, but the 

 disease occurs most frequently after the fourth month ; 

 earlier than this there are few symptoms. Sometimes 

 there is discharge of mucus from the vagina,- and the 

 vulva may be slightly swollen. There may be small 

 yellow ulcers on the mucous membrane lining the vagina, 

 which can be seen by opening the vulva. As the cow 

 is farther along in pregnancy, the signs of abortion 

 are those of approaching parturition; there may be a 

 rope of mucus hanging from the vulva, the milk 

 secretion may start, and the cow be "down in her 

 hips." 



When a cow shows signs of aborting, or has aborted, 

 she should be isolated from other cows, and the place 

 where she has stood should be thoroughly disinfected 



