Infectious Abortio7i hi the Cow. 495 



the veterinarian, in case such examination is made, to thorough- 

 ly disinfect the tail, buttocks and perineum of the mare about 

 to be examined and then thoroughly disinfect his arms and 

 hands after the examination, before proceeding to the next mare. 

 The handling of dystokia dependent upon contagious abortion 

 is the same as that of dj'siokia due to other causes. The se- 

 quelae of abortion, such as retained placenta, metritis, laminitis, 

 etc., present the same symptoms and are subject to the same 

 rules of handling as apply to these diseases following parturition, 

 and will accordingly be considered along with the post-parturient 

 maladies. The disinfection of the animal should be complete. 

 The disinfection of the veterinarian's person and his equipment 

 should be emphasized, although in all obstetric work this pre- 

 caution should be ample and should render the veterinarian 

 secure against becoming a bearer of any infection to animals which 

 he may later attend. 



B. Infectious Abortion in the Cow. 



For more than half a century, the leading veterinarians of the 

 world have recognized the fact that most abortions occurring in 

 cows are of an infectious character. The infectiousness of 

 abortion was quite generally denied until near the middle of the 

 19th century, but even during the 18th century there were vet- 

 erinarians who had become thoroughly'- convinced of its trans- 

 missability. When a very large number of abortions occurs in a 

 given herd or in a community during a short period of time, they 

 are quite uniformly traceable to infection. 



Infectious abortion of cows occurs chiefly in dairy herds and 

 only rarely among animals bred for beef purposes. It is not so 

 much a question of the susceptibility of one animal as of the 

 environment of the respective animals and the interchange of 

 animals, by which the disease may be spread from one herd to 

 another. Dairy cows are kept confined in close contact with 

 each other throughout a part or the whole of the year, so that 

 there is a better opportunity for infection by ordinary contact. 



Another element which tends to largely confine the malady to 

 dairy herds is the fact that among dairymen there is frequent in- 

 terchange of cows and bulls for breeding purposes. Among 

 breeders of beef cattle, the interchange of animals is compara- 

 tively rare and consists chiefly in the breeder buying young bulls. 



