PART XIII. 

 HERNIA. 



Definition. —The term hernia is applied to a protrusion of a 

 portion of the abdominal contents through a normal or an 

 abnormal opening in the abdominal wall. The larger number 

 of hernias is found under the skin, the smaller through the 

 diaphragm. 



Occurrence.— Hernia is very frequent in the dog but rather 

 rare in other small animals. 



General Remarks. —Hernia may consist of a portion of the 

 bowel (enterocele), a section of the omentum (epiplocele), or 

 a combination of both (entero-epiplocele) ; further, a portion 

 of the uterus may be protruded (metrocele), or the uterus and 

 its ligamentous attachments (metro-mesometrocele) . Some 

 of the other organs are occasionally found in the hernial sac, 

 such as the liver (hepatocele) , etc. In the dog it is possible 

 to find almost any one of the organs of the abdominal cavity 

 present in the hernial sac. The number and forms of hernia 

 are quite varied. 



The following parts are distinguished in a hernia: (a) 

 Hernial sac, (b) hernial ring, (e) hernial contents. 



(a) The hernial sac consists of the skin, subcutaneous 

 cellular tissues, and in most cases the peritoneum. Some- 

 times the peritoneum is ruptured and when this occurs the 

 skin and subcutaneous tissues constitute the hernial sac. 



(b) The hernial ring is the opening through which the 

 contents pass from the abdominal cavity. In recent hernias 

 the ring is made up of the margins of the muscular tissue, and 

 its size is determined by the rent in the abdominal wall. In 



