46 DISEASES OF CATTLE. 



In old cows what is termed spontaneous hernia n;ay sometimes take 

 place without any direct injury. The occurrence of this form of hernia 

 is explained by the increase in the size of the abdomen, which takes 

 place in an advanced stage of pregnancy, causing a thinning and 

 stretching of the muscular fibres, which at last may rupture or give 

 way. Such hernia frequently occurs about the end of the period of ges- 

 tation, and in some instances have contained the right sac of the rumen ? 

 the omentum, the small and large intestines, a portion of the liver, and 

 the pregnant uterus. 



In old hernia the swelling is soft and elastic, and if they have not 

 contracted adhesions to the sides of the laceration they can be made to 

 disappear on pressure beiiig carefully applied. Sometimes this acci- 

 dent is complicated by a rupture of the rumen, constituting a compli- 

 cated hernia. If a portion of the contents of the rumen escape into the 

 abdomen the case will be aggravated by the occurrence of peritonitis. 

 The occurrence of such a complication is best ascertained by examining 

 the animal immediately after the accident, when nothing intervenes 

 between the surface of the rumen and the hand but the skin. 



HERNIA OF THE BOWEL. (See Plate III, Fig. 6.) 



When the intestines form the contents of the hernia it will be situ- 

 ated at the right side of the abdomen. In an intestinal hernia the 

 swelling is usually not painful, of a doughy consistence or elastic, 

 according as the intestine does or does not contain alimentary matter. 

 This swelling can generally be made to disappear by pressure, and 

 when it has been reduced one can easily recognize the direction and 

 extent of the hernial opening. Herniao of the bowel which are situated 

 at the upper and right side of the abdomen are usually formed by the 

 small intestine. They are less easily reduced than hernia in a lower 

 situation, but when reduction has been effected they are less readily 

 reproduced than those occurring lower. In hernia of the small intes- 

 tine adhesion of the protruding parts to the walls of the opening, or 

 strangulation, are complications w^hich sometimes take place. If adhe- 

 sion has taken place the hernia can not be reduced by pressure, and 

 when strangulation has occurred the animal shows symptoms of pain. 

 In such, a case the edges of the opening through which the bowel has 

 passed press on the bowel so as at first to excite pain, then inflamma- 

 tion, which if unrelieved usually terminates in gangrene. The animal 

 is restless, turns its nose to the painful part, and shows those symp- 

 toms which, are usually collectively designated under the term colic. 

 When the swelling or hernia contains a portion of peritoneum the 

 swelling is soft and doughy, and does not produce the sensation on 

 handling it that it does when it contains gas or alimentary matter. 



HERNIA OF THE RENNET OR FOURTH STOMACH. 



This disease occasionally occurs in calves and is usually caused by a 

 blow from a cow's horn on the right flank of the calf, and this may hap- 



