ENZOOTIC ABORTION IN COWS. 123 



under the same hygienic-dietetic conditions that have always 

 existed ? 



This may he aU theory, but it is only by reflecting and 

 carefully weighing all the evidence that we can find a way 

 to proceed in the search after the cause. Then, the evidence 

 of practical ol)servation, supported, as I shall show, by some 

 experiments, is that it is capable of extending from cow to 

 cow in a Uable where it onc^ gains entrance. This would 

 make it contagious. Only the most exact and experimental 

 scientific differentiation, based on months of study and obser- 

 vation, can ever hope to elucidate questions of this nature. 



Dr. Salmon, Massachusetts Agricultural Report, 1883, 

 gives evidence of its mixed nature and of the preventive 

 value of disinfection. Brauer (German) caused the trouble 

 to cease after cleansing and disinfecting infected stables. 

 He caused a pregnant cow to abort in nine days after injecting 

 into her vagina some of the lochia! discharge from a cow that 

 had previously aborted. Similar results followed in 12, 15 

 (twice), 21 and 11 days in a corresponding number of cases 

 from the use of the same material. 



Lehnhert, also, speaks equally well of disinfection, etc., 

 and has produced the same results by experiment with the 

 same material in two cows at the seventh month of gravidity, 

 abortion resulting in eighteen and twenty days, respectively. 

 He recommends the speediest possible removal of the after- 

 birth, with the immediate and repeated disinfection of the 

 birth-passages, and the immediate removal of the other preg- 

 nant cows from the stable. 



Roloff thinks it due to some infectious miasma which en- 

 ters per vagina to the uterus. He reports seeing the vulva 

 and vagina swollen and injected in such cows anticipatory 

 to abortion. Disinfection is valuable and the onl}^ means of 

 prevention. 



Franck * has similar views and has performed similar ex- 

 periments to Brauer's with like results. The reports discov- 

 ering a peculiar bacterial growth, Leptothrix, on the vaginal 

 walls in such cows, which greatly increased in qiiantity until 

 abortion took place. 



* Late director Bavarian Veterinary School at Munich. 



