382 HERNIAL RUPTURE 



some portion of the large intestine or uterus, and more rarely the bladder 

 or stomach. Under certain conditions we find a certain cjuantity of 

 fluid lying in the sac. This is generally serum and originates from 

 venous stagnation. 



According to the location of the hernial orifice we distinguish 

 umbilical, ventral, inguinal, scrotal, and hernia of the diaphragm. 



The causes of hernia are generally described as dii-ect and indirect. 

 In the former we have a certain number of abnormalities which are due 

 to diseased conditions. For instance, an umbilical hernia is due to an 

 imperfect closure of the opening of the umbilical ring. The latter may 

 occur from the abdominal walls being flaccid, from cicatricial contrac- 

 tions after operations, and occasionally from great abdominal pressure in 

 prolonged straining, vomiting, etc., the muscular wall is ruptured, or 

 from kicks or blows on the abdomen. 



In traumatic hernia which has been caused by blows, the hernial 

 pouch is sometimes absent and its contents are surrounded by a hernial 

 envelope — in most cases by the skin — and in rare instances certain 

 muscles are included in the sac. 



Clinical Symptoms and Course. — The symptoms as well as the 

 course show a marked difference, according to the character of the hernia, 

 and it depends to a large extent on the ''possibilities" — that is to say, if 

 the hernia can be reduced and replaced in the abdominal cavity or not. 



Reducible Hernia. — This is generally seen in the region of the wall 

 of the abdomen. AVe find a swelling which does not present any inflam- 

 matory symptoms, and is especially prominent when the animal is 

 walking or standing. It is also seen during abdominal pressure, espe- 

 cially after the dog has eaten a hearty meal. If the animal is turned 

 in such a way that the hernia occvipies a superior position, as a rule it 

 immediately disappears, as the contents fall back into the abdominal 

 cavity, or they may do so on a slight pressure of the hand. If we exam- 

 ine the abdominal walls the orifice of the hernia can be distinctly felt, 

 and we may even be aljle to penetrate the abdominal cavity with the 

 finger. 



Further symptoms depend upon the nature of the prolapsed intes- 

 tines. This intestine will l)e recognized as a soft, elastic swelling, 

 having to a certain extent the round or tubular form of an ordinary 

 intestine. It may also l)e further distinguished by a slight distention 

 wdiich is generally due to gas or air. The omentum is soft and doughy 

 to the touch, having an uneven surface and dull on percussion. Hernias 

 of the horns of the uterus are only distinguished from a loop of intestine 

 after conception and during whelping. 



Mechanical influences, such as bites, blows, contusions etc., may 

 cause inflammation of the hernia with a thickening of the pouch, and 



