HERNIA OF THE ABOMASUM. 493 



abdominal walls in a dependant position, the hernial swelling steadily 

 grows in size in consequence of the weight of the food which is constantly 

 thrust in this direction by the contraction of the rest of the rumen, and 

 recovery is impossible. The only resource is to fatten the animals as 

 quickly as possible for slaughter. 



HERNIA OF THE ABOMASUM. 



Causation. This condition is due to causes similar to those above 

 mentioned, including mechanical violence. It is rare in adults, but 

 much commoner in young animals, especially in sucking calves, where 

 the abomasum is the most highly developed digestive compartment. 



Hernia of the abomasum is produced essentially and almost ex- 

 clusively by horn thrusts inflicted when calves attempt to suck cows 

 other than their own mothers. 



Symptoms. Hernia of the abomasum always occupies a certain 

 position in the lower part of the right flank, or, rather, in the space 

 comprised between the white line and the lower part of the circle of 

 the hypochondrium. 



The immediate symptoms are similar to those of hernia of the 

 rumen. They include : progressive swelling, formation of a peripheral 

 oedematous ring, interstitial sero-sanguineous exudation, which becomes 

 absorbed after a few days ; finally, the development of a hernia, formed 

 as a rule by the larger curvature of the viscus, which is in direct con- 

 tact with the abdominal wall. 



The lesions are those common to all hernia, and usually include 

 a partially healed wound. 



Diagnosis. The diagnosis is easy, particularly in calves, and the 

 possible existence of the condition should always be borne in mind when 

 dealing with injuries of the right pre-umbilical zone. An abscess of 

 the lower abdominal wall may occur at or near the umbilicus as a re- 

 sult of omphalitis or umbilical phlebitis, but it is readily distinguished 

 from a hernia. 



The prognosis is graver than in the case of hernia of the rumen, for 

 the displacement of the abomasum interferes with its regular function. 

 The prognosis varies, however, in accordance with the size of the hernia. 

 If the rupture is small, there is some chance that the abomasum, on 

 account of its longitudinal position, many penetrate but slightly into 

 the fissure. 



If, on the other hand, the rupture is large, the prognosis becomes 

 very serious. It is sometimes best to slaughter the animal, if in good 

 condition; otherwise an operation is necessary. 



