678 DISEASES OF SWINE 



and even form in the testicle in such amounts as to cause inabiUty 

 to perform normal function. This is hastened by the feeding of an 

 unsuitable diet which will have a tendency to make the animal 

 fat. These old fat boars become so lazy that they will refuse to 

 cover a sow, and they seem to lose all desire for sexual intercourse. 



Since the introduction of the serum method of treatment for 

 hog-cholera we have another frequent cause for sterility in boars, 

 due to an inflanomation of the testicles and scrotum following injec- 

 tion of serum in the muscles of the hind leg. Care should be used 

 in this connection, as the inflammation which follows the injec- 

 tion may rapidly travel upward and involve the scrotum, causing 

 the animals to be worthless for breeding purposes afterward. 



Other causes for loss of sexual ability on the part of the boar are 

 injuries and lack of development of the penis or of the testicles. 

 Injury, such as a blow on the scrotum, may result in starting up an 

 inflammation which leaves the animal incapable for breeding pur- 

 poses. In like manner the penis may become injured, broken, bit- 

 ten, or the seat of an inflammation, which destroys its value as an 

 organ of copulation. Sometimes a male animal will be seen in 

 which the penis or testicles have never properly developed. These 

 animals are, of course, worthless for breeding purposes and should 

 be castrated and fattened for market. 



Causes in the Female. — In the sow the causes for barrenness 

 are even more numerous than in the case of the male animal. In 

 some cases the condition is due to the fact that the sow is overfat. 

 This cause is especially met with in pure-bred animals that have 

 been pushed to the limit in order to get them in condition for ex- 

 hibition at fairs and other shows. This overfattening results in 

 fatty degeneration of the ovaries, and these organs become incap- 

 able of producing a healthy ovum, and, as a result, it is impos- 

 sible for the sow to become pregnant. 



In other cases there is an entire lack of development of the 

 ovary, and no ova, or only immature ones, are formed. In still 

 other cases tumors and cystic formations affect the ovary and 

 destroy its function. These cases in which the ovary is at fault are 

 the most serious ones and often remain permanent. The tubes 

 which lead from the ovary to the uterus may become inflamed or 

 plugged up with fat, and the ovum is then unable to reach the 



