740 Infectious Abortion, 



10. Infectious Abortion. Abortus Enzooticus. 



(Abortus infectiosus; Seuchenhaftes Verwerfen [German]; 



Avortement episootique [French]; Aborto 



enzootics [Italian].) 



Under the term "infectious abortion" are included those 

 cases which occur in otherwise healthy mothers, as a result 

 of external infection producing inflammatory lesions of the 

 uterine mucous membrane and of the fetal membrane. It 

 usually occurs in an enzootic form. 



History. As long since as the beginning of the last century this 

 disease was considered as contagious in several mountainous regions 

 of England (Lawrence, Skellet), and since then other authors (Ziindel, 

 St. Cyr) have maintained that an infection was the causative agent 

 in spite of the opposite view held by others (Hurtrel d'Arboval, Hering, 

 Stockfleth). The correctness of this view was however only established 

 by Franck (1876), and later by Lehnert (1878) and Brauer (1880), 

 by producing abortion artificially through the introduction of vaginal 

 discharge and fetal membranes into the vaginas of healthy cows. Later 

 Nocard (1885) called particular attention to the importance of the 

 inflammatory changes in the fetal membranes. Bang (1896) with the 

 cooperation of Stribolt, discovered the cause of infectious abortion 

 of cattle, which was later also investigated extensively by Preisz (1902), 

 while on the other hand Ostertag (1901) connected a streptococcus 

 with the cause of infectious abortion of mares. 



Occurrence. Infectious abortion occurs most frequently in 

 cattle breeding establishments, more seldom in studs and in 

 the breeding of sheep and swine. The stable-fed, finer bred 

 animals are especially affected, but the infection may become 

 widely spread in range animals (Kocourek, Keleti). The intro- 

 duction of the disease into large cattle herds causes heavy losses, 

 because of the fact that a number of unviable calves perish, 

 and because of the decrease of the milk production, moreover 

 the cows conceive only with difficulty after abortion or not 

 at all. 



Infectious abortion is -widely spread in all sections in which intensive stock 

 farming is in vogue. In Central Europe (Belgium, Denmark, Germany, France, 

 Austria, Switzerland, Hungary) and in England it appears frequently, especially 

 in cows, while in North America it appears that mares are especially affected. — 

 In England Mascall called attention to the disease as early as 1567, and during 

 the last century it gained such a foothold in the dairies that in certain localities 

 50-60% of the cows slunk their calves (McFadyean & Stockman recently could 

 show the disease in 36 shires) ; besides the disease appears frequently in horse 

 breeding and sheep raising establishments (Penberthy). 



Etiology. In cattle abortion is caused by a small, short 

 and comparatively thick bacillus (Corynebacterium abortus in- 

 fectiosi) which is non-motile, forms no spores; in artificial 



