sporadic or Accidental Abortion 471 



union between the fetal membranes and the uterus, and causes 

 infection, abortion is probable, if not inevitable. Perhaps it is 

 through some such examinations that the manipulations of these 

 parts have acquired the reputation of being highly dangerous. 

 It is evident that, if we need make manual exploration of the 

 vaginae of pregnant animals, we should do so with judgment and 

 be careful not to cause unnecessary disturbance. 



Since .severe hemorrhage of the mother tends to produce fatal 

 collapse of the fetus and is considered at times to cause abortion, 

 it is well that animals which are advanced in pregnancy should 

 not be submitted to operations accompanied by extensive loss 

 of blood. 



Mechanical insults probabh' play a highly important part in 

 the production of accidental abortion. They may act in a 

 comparatively direct manner upon the fetus as when some vital 

 portion of its body is lying in close contact with the abdom- 

 inal wall and receives a powerful blow from outside. More 

 commonly, mechanical injuries have their effect somewhat in- 

 directly by disturbing the connection between the fetal mem- 

 branes and uterus. Anything which can cause a separation be- 

 tween the maternal and fetal placenta tends to imperil the life of 

 the fetus. If the separation is comparatively slight, hemorrhage 

 occurs between the chorion and uterus, especially in animals 

 with diffused placenta, as the mare. The extension of this de- 

 tachment over a very wide area tends finally to cut off the blood 

 supply to the fetus and to induce uterine contractions, with 

 expulsion of its contents. If an animal well advanced in preg- 

 nancy falls violently, becomes cast in the harness or stall, or be- 

 comes mired, the violence of her movements may cause a de- 

 tachment between the chorion and uterus and lead to the death 

 and expulsion of the fetus. 



The jamming and jolting suffered by pregnant animals during 

 transportation by rail, and severe draft, is liable to bring about 

 injuries which may lead to abortion. When pregnant mares are 

 put to work where the draft is very heavy, or especially where 

 it is intermittent or jerky, the danger of injury to the young is 

 sometimes very great. Mechanical injuries are possible at any- 

 time, at work or pla}'. 



In dairies where the cows are kept in uncomfortable stanchions. 



