370 Veterinary Medicine. 



calves (pneumonia). Various kinds of infectious abortion. Acquired im- 

 munity, variable in different forms. Immunized cow still infecting. Symp- 

 toms. Lesions. Abortion in mares. Therapeutics. Prevention : Protec- 

 tion of a sound herd, guarantee with purchase, government control, precau- 

 tions with male or unimpregnated female, with pregnant. Extinction in a 

 herd, separation, disinfection, disposal of abortion, manure, urine, disinfec- 

 tion of animal, of genital organs, precautions as to service, new born, fields, 

 ewes. Disinfectants, subcutem or in muscles. 



Definition. The premature expulsion of the product of concep- 

 tion before it is viable out of the womb. Strictly speaking, a par- 

 turition in which the offspring is so far matured as to be viable is 

 a premature parturition , while if it is non-viable it is an abortion. 

 Vulgarly, however, as applied to herds, the term is used for any 

 early parting with the foetus. In this wider sense infectious 

 abortion is the premature expulsion of the foetus owing to an i7ifec- 

 tious catarrh of the womb, tra?is??iitled from one a?iimal to another 

 by the transference of the microbe. 



Synonyms. Infectious Abortion, Enzootic Abortion, Epi- 

 zootic Abortion. 



Animals Affected. Abortion is most common in cows, and less 

 frequent in ewes, goats, sows and mares. 



Forms and Accessory Causes of Abortion. It was formerly sup- 

 posed that abortion in herds was mainly due to mechanical and 

 chemical agencies acting injuriously on the system, and in adopt- 

 ing the explanation of a particulate, transferrable, infectious 

 agent for the habitual widespread forms of the disease, we should 

 not forget these accessory causes, many of which by themselves 

 cause sporadic abortions without the intervention of an infectious 

 element. 



The free consumption of ice cold water by the healthy dam 

 causes active gastro-intestinal peristalsis and vigorous movements 

 of the advanced foetus, which can be seen or felt in the right 

 flank, so that this is often resorted to, to determine whether the 

 animal is pregnant or not. If this is frequently repeated or car- 

 ried to excess in susceptible animals it will at times cause abor- 

 tions. As in all other cases of mechanical or physiological dis- 

 turbance, this is most operative at those periods of constitutional 

 changes, which if the animal had been unimpregnated would 

 have brought about ovulation and oestrum. 



