INKKCTIOrS ABORTION- 523 



2 BiiiiNC.S The corn fodder disease in cattle and other farm 

 animals, with especial relation to contagious pleuro-pneumonia in 

 American beeves in England. Bulletins No. 22 and ,3- ^ '"^- of Neb. 

 Agric. Ex'Per. Station, 1S92. 



. DF SCHWKINITZ. Chemical examination of comstalks presum- 

 ably the cause of cornstalk disease in cattle. Bulletin No. 10, U. S. 

 Bureau of Animal Industry. 1896. 



4. Gamgek. Diseases of cattle in the United States. U. S. Pe- 

 partinemt of Agriculture, 1869. 



5. Mavo. Cattle poisoning by nitrate of potash. Bulletin No. 49. 

 Kansas Ai^ric. Exper. Station, 1895. 



6. Mavo. Cornstalk diseases in cattle. Ibid, 1896. 



7 Moore. An investigation into the nature, cause and means of 

 preventing the cornstalk disease (Toxemia Maidis) of cattle, hnllettn 

 No. 10, U. S. Bureau of Animal Industry, 1896. 



INFECTIOUS ABORTION. 



^411. Characterization. The disease or condition 

 known as infectious abortion consists in the expulsion of the 

 immature fetus, usually before it has sufficiently developed to 

 live after birth, by a large proportion of pregnant annnals that 

 are kept together. U.sually the abortion occurs ni cattle be- 

 tween the fifth and eighth month of gestation. 1 he disease 

 as described bv European writers is characterized by certain 

 morbid changes in the uterine mucosa and fetal membranes. 

 American observers have not described these changes. In 

 cattle it usuallv aflfects the young cows. After two or three 

 consecutive abortions cows, as a rule, become immune to it. 

 Cows suffer most from this condition, although mares, ewes, 

 and other species are occa.sionally reported to be affected. 



In Norwav infectious abortion is scheduled under the so- 

 called "milder" contagious diseases." Tlie owner is obliged to 

 report when such a disease appears in his herd, and he is not 

 allowed to bring such animals to fairs or cattle .shows 



^ 412 History. Abortions in epizootic form have been 

 recorded from very early times. Mascal, in 1S59- gives direc- 



