ABORTION 117 



of pregnant cows ; in nine to fifteen days (period of incubation) 

 eleven cows aborted. These. experiments show that the infec- 

 tion may be transmitted by intermediaries. As such, we name: 

 Straw, manure, urine, ropes, stable paraphernalia and the arm, 

 of the operator. 



Franck reports that a cow which was examined for preg- 

 nancy per vaginam aborted after a decomposing placenta had 

 been removed that day (although the arm was thoroughly 

 cleansed.) 



Sand, who collected the reports of many Danish veterin- 

 arians, also mentions a case where abortion was transmitted by 

 a piece of afterbirth of a cow which had aborted. 



The transmission of the infectious material by the bull is 

 corroborated by many observers. Danish veterinarians report 

 striking examples. One breeding establishment introduced a 

 bull which while coming from a healthy herd had been for 

 several days at a farm where abortion existed, but did not come 

 in direct contact with the cows. This bull was placed at his 

 new home among the old cows which he was to serve while the 

 young cows were served by a young bull on the other side of 

 the farm. Of the old cows, twelve to fourteen aborted, the 

 young cows served by the young bull completing their period 

 of gestation. Later investigation showed that the old bull had 

 served some of the cows of the infected stable. Abortions- 

 persisted iu this case for two years (Nygaard, Sand). 



The experiences of Danish veterinarians tell us that cows^ 

 far advanced in pregnancy, when placed into an infected stable, 

 calve the first year at the regular time, but abort the following 

 year. Many examples have been enumerated, that in certain 

 divisions where abortion was stationary for two or three years, 

 only the first cows aborted. Experience further teaches that 

 the purchase of new cows and the sale of the aborting cows is 

 useless in a stable with stationary abortion. The newly bought 

 cows invariably abort the following year. 



Nocard states that in Michel at Azy abortion was permanent 

 for twelve years, and every year one- third of the cows aborted, 

 Every year abortion took place at a later period, so that in the^ 



