798 Diseases of the Genital Organs 



The lengthy discussion upon the question of abortion in 

 cows will serve in a general way for that in mares. Al- 

 though but recently the belief was general that each domes- 

 tic animal has a specific infectious abortion, numerous clini- 

 cal and biologic studies are causing a disintegration of that 

 theory. Up to the present time bacteriologists have gener- 

 ally incriminated but one organism as an important cause 

 of abortion in mares. Smith and Kilborne, Turner, Lign- 

 ieres, De Jong, Good and Smith, Meyer and Boerner, and 

 others have described an apparently identical organism, 

 designated by Good and Smith^ Bacillus abortivo-equinus, 

 which they severally believe is the cause, or an important 

 cause, of abortion in mares. Running through the recorded 

 investigations are frequent notes of discord. Good and 

 Smith failed to find the B. abortivo-equinus in fetal cadavers 

 or elsewhere in an outbreak among Shetland ponies, and 

 failed to report what other, if any, bacteria were encoun- 

 tered. In another case the highly suggestive admission is 

 made that the breeding stallion had orchitis and that from 

 the testicle was obtained, not B. abortivo-equinus, but B. 

 pseudomonas pyocyaneus, and that colonies of the same ba- 

 cillus were obtained from other sources in the outbreak 

 (fetal cadavers, fetal membranes?). The general attitude 

 of bacteriologists regarding the infections of the genitalia 

 of horses has been analogous to that in the investigations in 

 cattle : if the organism which has been set up as the specific 

 cause of abortion is present, the proof is complete and other 

 bacteria present may be ignored; if it is not present, the 

 abortion is not "contagious"^ though an abundance of bac- 

 teria of other kinds may be present. 



The hypothesis of "contagious abortion" in mares as a 

 specific disease has long held, and continues to hold, all ef- 

 forts at control in abeyance. There can be no reasonable 

 doubt at this time that a broader conception of the problem, 

 parallel to that which is now gaining a secure foothold re- 

 garding the genital infections of cattle and which has won 

 a safe place in the battle against these infections, is equally 



'Ky. Ag. Exp. Sta. Bui. 204, 1916. 



