480 Veterinary Obstetrics 



In two small villages, where there were 68 pregnant mares, 60 

 of them aborted. 



An extensive array of clinical observations as to the infectious- 

 ness of the disease might be added. They all have, the same 

 general character and force. The disease does not occur except 

 as a result of exposure to some animal, either directly or indirect- 

 ly, which has previously aborted, and when this exposure does 

 take place abortion is as liable to follow as is the occurrence of 

 any other contagious disease known to veterinary science. 



Experimentation affords good evidence of the infectiousness 

 of abortion in the mare. Ostertag, as already related, records 

 four cases, with abortion in two of the animals and suggestive 

 results in the other two. 



Guillerey cites one experiment, which in itself is admittedly 

 inconclusive. A piece of afterbirth from a mare which had 

 aborted was introduced into the vagina of a mare in the 9th 

 month of gestation. Two days later there was a muco-purulent 

 discharge and on the 3rd day the mare aborted. Here and there 

 in veterinary literature, occasional cases are mentioned where 

 mares have been caused to abort by experimental inoculation, 

 but the number of these is not extensive. So far as these ex- 

 periments have been carried, they are strongly indicative of the 

 infectious character of the disease. 



The bacteriologic researches of Ostertag and others furnish 

 additional proof of the infectious character of the disease. 

 Ostertag separated and cultivated a short streptococcus, which 

 produced abortion after experimental inoculation. The micro- 

 organism was obtained in pure cultures from the aborted fetus 

 and its membranes. 



We have further proof of the infectious character of the disease 

 in the- fact that it may be largely controlled by disinfection and 

 tbfe isolation of pregnant animals. The significance of this 

 proof will be brought out in our consideration of the control of 

 the disease. 



In common with the behavior of all infectious diseases, the 

 contagious abortion of mares is most frequently seen and attains 

 its greatest virulence in those regions where horse breeding is 

 most concentrated and the animals have a high value. This 

 involves, as a general rule, the close stabling of animals or their 

 being kept in close contact with each other upon pastures. 



