Sterility 197 



cases it may be necessary to make a small incision 

 in order to dilate the opening. It is probable that 

 mechanical manipulation of the parts, aside from the 

 mere dilation of the passage, is conducive to fertili- 

 zation, by increasing the blood supply to the part. 

 There are some mechanical contrivances, now on the 

 market, which are useful in dilating the mouth of the 

 womb, and increasing the probability of pregnancy, 

 especially in mares. 



A simple treatment that is known as the "yeast 

 treatment" gives good results in some cows that fail to 

 breed. Take a cake of compressed yeast and mix with a 

 pint of boiled warm water and allow to stand in a warm 

 place for twelve hours. When ready to use, add another 

 pint of warm water. This yeast mixture should be 

 injected, as far as possible, into the vagina of a cow at 

 the first signs of heat, and the cow bred as she is going 

 out of heat. 



Females that have aborted are not so likely to 

 breed, especially when the abortion has been due to 

 contagion. Tumors, malformations, or diseased con- 

 ditions of the genital organs in females, are frequent 

 causes of sterility. In mares that have been bred, 

 there is sometimes an opening from the vagina into 

 the rectum, through which pieces of dung often pass 

 and escape from the vulva. This opening usually 

 results from injury to the part while foaling. Such 

 mares do not breed readily and are liable to injury 

 in foaling afterward. In many cases this opening 

 between the rectum and the vagina can be closed by a 

 good surgeon and the mare becomes as valuable as ever 



