ABDOMIXAL HERXIA 383 



an adhesion between it antl the contents of the hernia. If the injury 

 is severe enough, we may have suppuration in the pout-h. In such 

 cases we may have a subsequent mechanical contraction and reduction 

 of the hernia, especially when the pouches are small, or in some cases 

 the hernia has only been large enough to admit a fold of the omentum. 



Irreducible Hernia. — This may be due to an adhesion of the intes- 

 tinal contents with the hernial pouch, the union of the intestinal 

 contents with each other (for instance, adhesion of the intestines), 

 from thickening of the omentum which lies in the hernial pouch, 

 or from strangulation of the hernia. This is especially important, as it 

 may occur in all cases of abdominal hernia and at any time. 



Concerning the causes of strangulation there are three important 

 groups: Strangulation by extreme distention of an intestinal tube by 

 fiecal matter; a distention of the opening of the hernia, which subse- 

 quently closes on the intestine and strangulates it; by the intestines 

 becoming twisted in the sac. Invagination is very frecpently seen in 

 young animals. 



In many cases we distinguish three stages of hernia, according to 

 the anatomical alterations produced as a consequence of strangulation 

 in the prolapsed parts. First, we have a venous hypersemia, then 

 inflammation, and lastly suppuration. In the first stage the veins and 

 capillaries are engorged with blood, and serum is exuded in different 

 directions. In the second stage we observe inflammation of a septic 

 character, which extends from the mucous membrane to the serous 

 membrane, as a consecjuence of the noxious or poisonous contents of the 

 intestines. In the third stage the prolapsed parts become necrosed, 

 due to the stricture of blood circulation. The intestinal portion becomes 

 lilack, easily torn, dull in color, and covered with gray or greenish spots 

 on its surface; the hernial fluid becomes purulent, and the inflammatory 

 processes in the intestine above the strangulation cause septic peritonitis. 



The clinical symptoms of strangulated hernia are very marked 

 in most cases. The hernia can no longer be reduced or pushed back 

 into the cavity, or a swelling suddenly appears after any traumatism, 

 or after great abdominal pressure, and cannot be reduced even with 

 careful manipulation. The hernia is distended, harder and fuller than 

 usual, becoming very sensitive to pressure, and especially so as the in- 

 flammation becomes more intense. The skin covering the hernia is normal 

 in the beginning, but later becomes red, swollen, and warm to the 

 touch. Another symptom generally present is vomiting. This may 

 be so constant and violent toward the later stages that the animal will 

 vomit faeces. At that period symptoms of severe intestinal obstruction 

 present themselves. The hernial swelling becomes cold, insensilile to 

 pressure, and symptoms of collapse appear, and death occurs in from 



