446 Veterinary Obstetrics 



The hernia may be due to traumatism, or to a congenital defect 

 in the abdominal wall, either at the umbilicus or the inguinal 

 ring. Sometimes, in the development of the fetus, the umbilical 

 ring remains so large that the abdominal viscera permanently 

 protrude through it, against the skin. Such an animal, when 

 grown, if permitted to become pregnant, and the hernial ring is 

 very large, is liable to uterine hernia and the fetus or fetuses 

 may develop in the hernial sac. Hernise of such dimensions are 

 rare in our larger domestic animals, but umbilic herniae are occa- 

 sionally met with, in the mare, of such size that, were she allowed 

 to go without treatment and be bred, a uterine hernia would in- 

 evitably result. 



In some animals, especially in the bitch and, sow, the ovary 

 and uterine cornua pass from their ordinary position through the 

 inguinal ring and reach the location of the testicle in the adult 

 male, in the perineal region. As a consequence, in case of preg- 

 nancy, the young may develop in this herniated portion of the 

 uterus, outside the abdominal cavity. 



The diagnosis of uterine hernia is comparatively easy. The 

 fetus or fetuses are so superficially situated that they may be 

 recognized by palpation. Sometimes the tumor is not reducible 

 because the fetus has become larger than the hernial ring and 

 consequently cannot be returned into the abdomen by pressure. 



The significance of these herniae will vary greatly according to 

 conditions. If occurring as the result of a recent accident, when 

 no hernial ring or sac has become established, the hernia tends 

 to enlarge rapidly because of the presence in it of the gravid 

 uterus and other viscera. In any hernia with a well established 

 ring and sac, into which the gravid uterus enters, the tendency 

 is for the sac to continue to grow, but for the ring to remain un- 

 disturbed. They have little risk generally for the life of the 

 mother until parturition comes on, when they may become a 

 serious menace to the lives of both mother and fetus. If the fetus 

 should be of too great size to readily pass through the hernial 

 ring or if there be an extensive hernia of recent date which has 

 destroyed the expulsive powers of the abdominal walls, active 

 obstetric interference may be demanded in order to save the lives 

 of parent and offspring. 



It is inadvisable, as a rule, to attempt to breed animals which 

 have hernise of such a character that it is probable that a fetus or 



