166 DISEASES OF CATTLE. 



deficient that the fetus dies in the womb and is expelled in conse- 

 quence. Excessive loss of blood, attended as it usually is with shock, 

 becomes a direct cause of abortion. 



Acute inflammations of important organs are notorious causes of 

 abortion, and in most contagious fevers (lung plague, rinderpest, 

 foot-and-mouth disease) it is a common result. Affections of the 

 chest which prevent due aeration of the blood induce contractions of 

 the womb, as shown experimentally by Brown-Sequard. Pregnant 

 women suffocated in smoke aborted in many cases. (Retoul.) 



Ergoted grasses have long been known as a cause of widesj)read 

 abortion in cows. The ergot is familiar as the dark purple or black, 

 hard, spurlike growths which protrude from the seeds of the grasses 

 at the period of their ripening. (PI. V.) It is especially common 

 in damp localities and cloudy seasons on meadows shaded by trees 

 and protected against the fre-e sweep of the winds. The same is to 

 a large extent true of smut; hence, wet years have been often re- 

 markable for the great prevalence of abortions. Abortions have 

 greatly increased in New Zealand among cows since the introduction 

 of rye grass, which is specially subject to ergot. As abortion is more 

 prevalent in old dairying districts, the ergot may not be the sole 

 cause in this instance. 



The riding of one another by cows is attended by such severe mus- 

 cular exertion, jars, jolts, mental excitement, and gravitation of the 

 W'omb and abdominal organs backward that it may easily cause 

 abortion in a predisposed animal. 



Keeping in stalls that slope too much behind (more than 2 inches) 

 acts in the same wa3% the compression from lying and the gravita- 

 tion backward proving more than a predisposed cow can safely bear. 



Deep gutters behind the stalls, into w'hich one or both hind limbs 

 slip unexpectedly, strain the loins and jar the body and womb most 

 injuriously. Slippery stalls in which the flooring boards are laid 

 longitudinally in place of transversely, and on which there is no 

 device to give a firm foothold, are almost equally dangerous. Driv- 

 ing on icy ground, or through a narrow^ doorway where the abdomen 

 is liable to be jammed, are other common causes. Aborting cows 

 often fail to expel the afterbirth, and if this remains hanging in a 

 putrid condition it is most injurious to pregnant cows in the near 

 vicinity. So with retained afterbirth in other cows after calving. 

 That some cows kept in filthy stables or with slaughterhouses near by 

 may become inured to the odors and escape the evil results is no 

 disproof of the injurious effects so often seen in such cases. 



The excitement, jarring, and jolting of a railroad journey often 

 cause abortion, especially as the cow nears the period of calving, and 

 the terror or injury of railway or other accidents proves incom- 

 parably worse. 



