372 'Veterinary Medicine. 



involuntary muscular fibre, is seen alike when used medicinally 

 and when acting as au accidental toxic agent in causing spasms, 

 nervous torpor or paralysis, delirium ; gangrene of the feet, tail 

 or tip of the ear \ or contraction of the womb and expulsion of its 

 contents. Like other agents mentioned ergot is at times an active 

 ecbolic when cooperating with other similarly operating agencies. 



Irritant vegetables of various kinds are to be dreaded. Such as 

 act on the bowels and kidneys, keeping up a constant diarrhoea 

 and diuresis, are quite liable to cause abortion in susceptible sub- 

 jects. Savin, tansy and rue have obtained a bad reputation in 

 this sense. 



Cotton root bark is an active ecbolic, but is not likely to harm 

 animals unless deliberately administered. 



Impaction of the rumen or manifolds, and obstinate constipation 

 with the resulting straining or compression must be named as an 

 accessory cause. 



Severe constitutional diseases-, especially the infectious fevers, 

 aphthous fever , lung plague, rinderpest, etc., are occasional causes 

 of abortion. 



It may be brought about by direct irritation of the womb, as 

 in ovariotomy or dilatation of the cervix, or again by death of the 

 fcetus through twisting of the umbilical cord. 



Where cattle are subjected to dry winter feeding, in the ab- 

 sence of ensilage or roots, on the magnesian limestones, small 

 calculi in the kidney are almost the rule in winter and the irrita- 

 tion caused by these conduces to abortion. 



Nor must mental influence be altogether ignored. Cows and 

 even mares are exceedingly .sensitive to the smells of decomposing 

 animal matter, as seen every day in the vicinity of abattoirs, or in 

 case the carcass of one of their fellows has been opened, and not 

 infrequently in connection with carrion, and the occurrence of 

 abortions after such excitement has been frequently noticed. 

 Cases are on record of specially susceptible cows having had 

 active labor pains, from being with another cow at the time of 

 parturition. Shepherds have noticed that violent thunder storms 

 have been followed by numerous abortions in the flocks. 



The Contagious Form. Any of the usual causes of sporadic or 

 accidental abortion may cooperate with the true infectious ele- 

 ment and give unusual energy to it, yet it is of the utmost im- 



