DISEASES OF SWINE 439 



should not be forced to walk, as this will retard recovery. After the 

 animal is able to walk, keep it away from other pigs for a few weeks. 

 (Ind. B. 100.) 



STERILITY, BARRENNESS. 



Sterility may exist in the male or female and may be temporary 

 or permanent. Some years the per cent of barren sows is very large. 

 The cause for the condition has not been ascertained. 



Causes. In the male impotency is sometimes a functional 

 trouble, due to improper development of the sexual organs or a 

 broken copulatory organ. Other causes are a fatty degeneration or 

 infiltration of the testicles, lack of physical or functional exercise and 

 old age. In the female, sterility may result from a greater variety of 

 conditions than in the male. Excessive fattening, as is sometimes 

 seen in sows fitted for exhibition purposes, will cause it. This may be 

 due to the ovaries becoming so infiltrated with fat as to interfere with 

 their function, or to an occlusion of the passages with fat. In the 

 former case the change is often so great that nothing will insure a 

 complete return to the normal, but in the latter the function can be 

 restored by reducing the condition of the sow. Sometimes a rigid os 

 prevents the entrance of the seminal fluid into the womb. Such a 

 condition may occur in young or aged sows. Inflammation of the 

 lining membrane of the uterus or vagina may also cause it. In this 

 condition a discharge, usually so slight as to escape notice, occurs, 

 and when the male element comes in contact with the abnormal se- 

 cretions, it is destroyed. In old age barrenness occurs. Faulty devel- 

 opment of the generative organs is not uncommon in sows. The 

 uterus may be abnormally small, the ovaries rudimentary and the 

 vagina and os imperforate. In these cases, the sow may never come 

 in heat and never conceives. 



Treatment. Excessive fat is a frequent cause of sterility in both 

 the male and the female and must be overcome by dieting and ex- 

 ercise. The male should not be used to excess and should be kept in 

 a healthy, vigorous condition. If the os is rigid and closed, prevent- 

 ing the entrance of the seminal fluid into the womb, it should be 

 dilated. Closure of the maternal passages by fat can be overcome by 

 a proper diet and plenty of exercise. (Ind. B. 100.) 



ABORTION. 



Abortion or slipping of pigs is a troublesome problem with 

 which to deal. There seems to be two varieties in these animals, the 

 same as in the other domestic animals, sporadic and infectious. The 

 sporadic form is the variety most often met with and is due to acci- 

 dents, as slipping, falls, being kicked by a horse, or hooked by a 

 cow, by being run by dogs, or worried by other sows in heat, or by a 

 boar, to spoiled or musty food, to "piling up" in bed, to sudden ex- 

 posure to cold and to the effects of some other disease, as cholera. It 

 can readily be observed that these causes will not as a rule act upon 

 many sows in the same herd with sufficient violence to cause abor- 

 tion, as the sow does not abort easily. After an outbreak of cholera 

 we expect a considerable percentage of abortion. While an infectious 

 abortion of the sow has not been described, the Station has been the 



