DISEASES OF CATTLE 169 



while its bones remain for years in the womb inclosed in the re- 

 mains of the fetal membranes. These may be expelled at any time 

 through the natural channels, or they may remain indefinitely 

 in the womb, not interfering with the general health, but prevent- 

 ing conception. 



If the true condition of things is recognized at the time of the 

 subsidence of the labor pains, the mouth of the womb may be 

 dilated by the fingers, by the insertion of sponge tents, or by a 

 mechanical dilator the fetal membranes may be ruptured and the 

 calf extracted. After the removal of the calf and its membranes 

 the danger of putrid poisoning may be obviated by injecting an anti- 

 septic solution. 



ABORTION (SLINKING THE CALF). 



Technically, abortion is the term used for the expulsion of the 

 off-spring before it can live out of the womb. Its expulsion after 

 it is capable of an independent existence is premature parturition. 

 In the cow this may be after seven and one-half months of preg- 

 nancy. Dairymen use the term abortion for the expulsion of the 

 product of conception at any time before the completion of the full 

 period of a normal pregnancy, and in this sense it will be employed 

 in this article. 



Abortion in cows is either contagious or noncontagious. It 

 does not follow that the contagium is the sole cause in every case 

 in which it is present. We know that the organized germs of con- 

 tagion vary much in potency at different times, and that the ani- 

 mal system also varies in susceptibility to their attack. The germ 

 may therefore be present in a herd without any manifest injury, 

 its disease-producing power having for the time abated consider- 

 ably, or the whole herd being in- a condition of comparative insus- 

 ceptibility. At other times the same germ may hav^e become so 

 virulent that almost all pregnant cows succumb to its force, or the 

 herd may have been subjected to other causes of abortion which, 

 though of themselves powerless to actually cause abortion, may 

 yet so predispose the animals that even the weaker germ will 

 operate with destructive effect. In dealing with this disease, there- 

 fore, it is the part of wisdom not to rest satisfied with the discovery 

 and removal of one specific cause, but rather to exert oneself to 

 find every existent cause and to secure a remedy by correcting all 

 the harmful conditions. 



CAUSES OF NONCONTAGIOUS ABORTION. 



As abortion most frequently occurs at those three-week inter- 

 vals at which the cow would have been in heat if nonpregnant, we 

 may assume a predisposition at such times due to a periodicity in 

 the nervous system and functions. Poor condition is often a pre- 

 disposing cause. This in its turn may result from poor or insuffi- 

 cient food, from the excessive drain upon the udder while bearing 

 the calf, from chronic wasting diseases, from worms, from dark, 

 damp, unhealthy buildings, etc. In some such cases the nourish- 

 ment is so deficient that the fetus dies in the womb and is expelled 



