HERNIAL BUPTUBE. 321 



The causes of hernia are generally described as direct and indi- 

 rect. 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 umbili- 

 cal ring. The latter may occur from the abdominal walls being 

 flaccid from cicatricial contractions after operations, and occa- 

 sionally 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 Coukse. 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 " possibili- 

 ties " — 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. We find a swelling which does not present 

 any inflammatory symptoms, and is especially prominent when the 

 animal is walking or standing. It is also seen during abdominal 

 pressure, especially after the dog has eaten a hearty meal. If the 

 animal is turned in such a way that the hernia occupies 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 pres- 

 sure of the hand. If we examine the abdominal walls the orifice 

 of the hernia can be distinctly felt, and we may even be able to 

 penetrate the abdominal cavity with the finger. 



Further symptoms depend upon the nature of the prolapsed 

 intestine ; this intestine will be recognized as a soft, elastic swell- 

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

 ordinary intestine. It may also be further distinguished by a 

 slight distention which is generally due to gas or air. The omen- 

 tum is soft aud doughy to the touch, having an uneven surface and 

 dull on percussion. Ruptures of the bladder may be distinguished 

 by the acute symptoms of hernia and also by the entire absence of 

 urination. Hernias of the horns of the uterus are only distinguished 

 from a loop of intestine after conception and during whelping. 



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