236 ANNUAL REPORT OF THE Off. Doc. 



abort. In some cases as high as 100% have been known to abort 

 in certain years. The losses in young animals year after year in 

 infected breeding herds are placed at 20%, and the money losses in 

 infected herds is averaged at about $35.00 per head. In dairy cows 

 that abort there is a decrease in the amount of milk produced. The 

 act is likely to be followed by temporary or permanent sterility, 

 udder diseases, septic condition of the uterus and a total loss of 

 many calves. 



This form of abortion has been known to be infectious for more 

 than a century. The "Complete Farmer," an agricultural paper 

 published in England, speaks of the disease as contagious as early 

 as 1807. Sensible advice was given in this article in reference 

 to its spread and how to control it. Professor Bang, of Copenhagen, 

 who has done so much good work on many important diseases of 

 animals and especially tuberculosis, discovered the true cause of the 

 disease in 1896. The organism that causes it has been named the 

 bacillus of Bang in honor of its discoverer. His discovery has since 

 been verified in many countries. It has been found in practically 

 all countries where cattle are kept. True infectious abortion in 

 cattle is always due to the bacillus of Bang. The disease is found 

 in nearly all species. In animals except bovines, however, the dis- 

 sease is not due to the bacillus of Bang. True infectious abortion 

 of cattle has been transmitted experimentally to other species but 

 under natural conditions that of one species of animals is not car- 

 ried to another. It is uncommon to find two or more species of 

 farm animals afflicted with infectious abortion at the same tim«. 

 The disease is of the most importance in bovines. Mares are not 

 seldom afflicted with a form of infectious abortion in the horse breed- 

 ing sections of Pennsylvania. Abortion in animals has been recog- 

 nized for centuries. In the XXXI chapter of Genesis, the 38th 

 verse it speaks of sheep and goats casting their young. The con- 

 dition is not always due to infection. Isolated cases are usually 

 due to fright, injury, certain poisons, diseases like anthrax, foot-and- 

 mouth disease, excessive activity of the milk gland, etc. The relative 

 frequency of infectious abortions as compared with those due to 

 accidental causes has been observed by one veterinarian who kept a 

 record of three hundred cases. He found that two hundred and 

 eighty were due to infection and the balance to other causes. 



Breeders frequently speak of the condition as slinking, slipping, 

 casting, picking, etc. The disease is easily recognized in a herd. 

 It is not so easy to pick out the infected animals. The diagnosis 

 is usually made by the history. Where several animals ab'ort during 

 the season and no other cause can be found, one is usually safe in 

 judging it to be due to infection. It may occur any time during 

 pregnancy, but is most common from the fifth to the seventh month. 

 The average period of gestation at which 240 cases aborted was 6^ 

 months. Young cows are more liable to abort than the older mem- 

 bers of the same herd. Other valuable observations made on the 

 240 head of aborters showed the average age at which it occurred 

 to be 4^ years, 8% aborted a second time, 2% the third and 168 

 retained the afterbirth. Ko symptoms are observed usually till just 

 before the act. They vary to a certain extent with the period of 

 gestation. In the early stages no clinical symptoms may be de- 

 tected while toward the end of gestation they simulate more closely 

 those of normal parturition. The calf may live any time after the 



