The Vet. Book 



Conveniently one may reply that an abortion 

 occurs before the sixth month, and the fcetus is 

 either born dead or expires immediately afterwards ; 

 whereas a premature birth takes place any time 

 after the sixth month, but before the full period 

 of gestation has arrived, and the fcetus is born 

 alive, and has a chance of surviving, provided that 

 favourable circumstances are present. 



There are two forms of abortion, one being 

 called enzootic (or infective), and the other 

 sporadic, i.e. arising without any apparent source 

 of infection. Enzootic abortion is a most trouble- 

 some malady amongst cows and ewes, and occasion- 

 ally in mares. It is due to (according to scientific 

 investigation of the late Professor Frocard) micro- 

 organisms and the infective material or abortion 

 virus is contained within the vaginal discharge, 

 issuing from an infected animal ; and when this 

 gains admission into the vaginal mucous membrane 

 of other pregnant animals, it is liable to provoke 

 abortion. The discharge adheres to the hind- 

 quarters •, to the tail ; etc. and may easily gain ad- 

 mission through the channel named. 



Previous to the investigation of Frocard it was 

 thought that abortion arose through sympathy, 

 whereas it is due to infection. 



Abortion arises from other causes, such as 

 fright, the action of certain grasses or herbs, 

 external violence, disease of the generative organs, 

 tuberculosis, etc. etc. 



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