ABORTION 113 



chorion and uterine mucosa is mostly obliterated, so that the 

 foetal envelopes follow the birth of the calf— a very favorable 

 factor, considering the process of involution about to follow. 



The expulsion of a small foetus at this period of gestation 

 as a rule offers no difficulties. A definite position does not 

 exist at this time ; the foetus is usually born in the anterior 

 presentation. The process of involution now terminates 

 quickly ; for three or four days after parturition a little hemor- 

 rhagic mucus is dischatrged from the vulva. This ceases and 

 the cow again is normal. In the heifer the whole process is so 

 trivial that none but an observing attendant would notice it. 



Abortion occurring in the second half of pregnancy gives 

 rise to more characteristic symptoms, and the general state of 

 health often is disturbed, even when but temporarily. Abortion 

 frequently happens in the seventh month. 



Premonitory symptoms. — Cows which are still giving milk 

 at this time — usually the case in localities where they are dry 

 only for six weeks — decrease in milk, and its color and consist- 

 ency closely resembles colostrum. This is the first sign induc- 

 ing the attendant to watch her. At this time he can usually 

 observe more, if not on the same day, then on the following one. 

 A limited infiltration of the broad pelvic ligaments has taken 

 place, their posterior border is no longer tense and the liga- 

 ments begin to sink down. In some cases the vulva is tumefied, 

 and when the animal is emaciated the flanks are fallen in. 

 Abortion is often preceded by vigorous movements of the foetus. 

 These are reflex movements and are caused by the asphyxiated 

 state of the foetus, due to an accumulation of carbon dioxide in 

 the circulation of the placenta. A rather sudden swelling of the 

 udder at this time is seen in primiparse, which suggests an 

 approaching abortion. After these symptoms have extended 

 over two, sometimes three days, the prodromes of parturition 

 manifest themselves ; in the beginning the animal strains a 

 little now and then, confining itself to the uterine contractions; 

 later the abdominal muscles assist, and regular labor pains set 

 in. The, premonitory symptoms may escape the attendant, 

 while the latter phenomena induce him to fear abortion. 



