CHAPTER XXVII. 



BACILLUS OF INFECTIOUS ABORTION STREPTOCOCCUS IN ABOR- 

 TION IN MARES STREPTOCOCCUS OF VAGINITIS 

 VERRUCOSA OF CATTLE. 



BACILLUS OF INFECTIOUS ABORTION. 



Occurrence and Historical. Infectious abortion, abortus enzooticus 

 "Seuchenhaftes Verwerfen" (German), "avortement epizootique" 

 (French), is the name given to that form of abortion in cows not 

 due to accident or external influences or to ergot contaminated fodder, 

 but to a specific microorganism known as the bacillus of infectious 

 abortion of Bang. That this form of abortion in cows is infectious in 

 character was recognized more than a hundred years ago in England. 

 Frank, Lehnert, and Braeuer, between 1876 and 1880, proved this 

 contention by infecting healthy cows from the vaginal discharges of 

 cows which had aborted. Nocard, in 1885, studied the anatomic 

 changes of the disease, while Bang, assisted by Stribolt, discovered 

 the specific bacillus in 1896. Its etiologic relationship to the disease 

 was confirmed by Preisz in 1902. Infectious abortion in cows has 

 been observed in various countries in Europe, also in the United 

 States. It was studied by Chester, Law and Moore, who failed 

 to find Bang's bacillus, but instead an organism which appeared to 

 belong to the colon-hog-cholera group of bacteria. 



Pathologic Lesions. According to Bang's findings, made on 

 material very favorable for the study of the affection, the external 

 serous surface of the uterus is normal, the cervical canal closed by 

 tenacious mucus. An abundant, not fetid, exudate, consisting of a 

 dirty yellowish, thin, mushy material, containing lumpy, mucoid 

 masses and presenting in some portions where most of the fluid 

 had been absorbed a semisolid character, is present between the 

 uterine mucosa and the ovum. The exudate is alkaline in reaction. 

 After its collection in a conical glass it separates into two layers, an 

 upper composed of a reddish-yellow cloudy serum and a low^er one 

 of a thick, dirty, grayish sediment. The chorion upon section presents 

 on its inner surface a gelatinous substance in which thin membranes 

 are found. This layer is the delicate connective tissue between 

 chorion and allantois in a condition of edematous infiltration. The 

 latter extends to the fetus and spreads into it to the depth of about 

 1.5 cm. and also into the umbilical cord. The allantois and amniotic 

 fluids are normal. The exudate between the uterine mucosa and the 



