104.8 Veterinary Obstetrics 



may increase the intra-abdominal pressure, such as severe ex- 

 pulsive efforts due to the retention of the meconium, or to con- 

 stipation of the bowels, may cause a marked increase in the size 

 of the hernial sac. The same increase in size may be caused by 

 the allowance of large quantities of bulky food. 



Fleming cites Zundel and others in support of his belief that 

 environment, and especially the character of food, tends to in- 

 duce the disease. He believes that the young of animals kept 

 upon low and marshy pastures, or subsisting upon soft, luxuriant 

 herbage during a rainy season, are especially subject to hernise. 



The majority of writers, with whom we are in full accord, 

 consider the defect to be chiefly hereditary. We have repeatedly 

 observed the strong hereditary tendency of this defect. In one 

 instance a client purchased an imported French draft stallion 

 for service in a valuable stud of pedigreed draft mares, in the 

 progeny of which, umbilic hernia had previously been unknown. 

 The first crop of foals showed about 50% of umbilic herniae. The 

 stallion was promptly sold, and umbilic hernia did not recur the 

 following sea.son or thereafter. We have noted the same heredi- 

 tary tendency among swine, where a farmer has been careless in 

 the selection of his breeding animals. In some cases we have 

 observed an entire litter of pigs affected with herniae. It is in- 

 teresting to note that, in the pig at least, umbilic and scrotal 

 hernia seem to be interchangeable, so that, in a given litter of 

 pigs, males may suffer from scrotal or umbilic hernia indiffer- 

 ently, or even from both, while the females show only the 

 umbilic defect. 



Symptoms. There is present, at the umbilicus, a tumor, 

 which may be either spherical or pyriform or may be more or 

 less elongated from before to behind. The size of the hernial 

 ring varies greatly according to species and individual. In the 

 puppy it may be ^ to i inch in diameter ; in the foal i to 6 

 inches in diameter. 



The character of the tumor, as revealed by palpation, neces- 

 sarily depends upon the contents of the hernial sac, and the 

 question of their incarceration or freedom to return into the ab- 

 dominal cavity. The contents of the hernial sac usually consist 

 of portions of intestine containing liquid feces, or of portions of 

 the omentum. Except these become incarcerated, a soft, fluctu- 

 ating tumor results, which is usually readily pushed upward into 



