172 DISEASES OF CATTLE. 



Douching of the external genitals of the bull, a practice formerly 

 regarded as highly important for preventing the spread of the dis- 

 ease, is now recognized as being of doubtful value. The bull is pro- 

 tected from abortion infection to a great degree by permitting him 

 to serve only such animals as have calved or aborted from six weeks 

 to two months previously. Investigational work has indicated that 

 when the bull is affected with the disease the organs of his generative 

 system commonly involved are not reached by the antiseptic solutions. 

 A more rational method for the prevention of the spread of the dis- 

 ease by the bull consists in keeping him in an inclosure separate from 

 the females and in having all services take place on neutral ground. 



Great care should be used in purchasing cattle, and cows not known 

 to be free from the disease should be kept in separate quarters until 

 this point is determined. 



GRANULAR VENEREAL DISEASE (INFECTIOUS GRANULAR 

 VAGINITIS). 



The affection to Avhich the foregoing names have been given is a 

 chronic, mild, and apparently contagious disease of cattle, character- 

 ized by an inflammator}' condition of the mucous membrane of the 

 vagina and the development of nodules upon its surface. 



This disease is very widely spread, but from an economic point of 

 view it does not appear to have great significance. Williams, who 

 investigated it, asserts that it is difficult to find a single herd in this 

 country which is free of this disease. He considers it of great im- 

 portance, claiming that granular vaginitis has a vital relation to 

 abortion. This view, however, is not substantiated by other investi- 

 gators, it being now generally accej)ted that the disease is only rarely 

 responsible for abortion, and further, that it exerts no apparent ill 

 effects on the health of the animal and that it has no effect on the 

 milk yield. 



Symptoms. — Natural infection may take place either by direct 

 contact of animals or at the time of service. Most of the cows in the 

 affected herd contract the disease, but the bulls are rarely or very 

 mildly affected. The inflamed condition of the membranes of the 

 vagina results in a catarrhal exudate, and this discharge, which soils 

 the external genitals and the tail, and the uneasiness and sometimes 

 the straining of the animal, are the first and most prominent symp- 

 toms observed. Upon examination, small, hard, grayish nodules can 

 be seen and felt upon the inflamed membranes. This acute stage 

 may last for three or four weeks, then it gradually subsides and 

 assumes the chronic form, only to flare up again as the animal comes 

 in heat. 



These nodules are sometimes found on the membranes of the 

 uterus, and some investigators have argued from this fact that it 

 was responsible for abortion and sterility. Others, however, deny 

 this and point out that the bacillus of abortion can be demonstrated 



