536 



Chronic Interstitial Hepatitis. 



liorse, carnivora and swine, tins encroachment may be bilateral 

 but in the ox it is only on the right side and then only as far 

 as the anterior part of the hollow of the flank. Similarly it is 

 only very exceptionally that the enlargement is sufficient to 

 allow of palpation of tlie organ per rectum. In these cases it 

 can be felt in the neighborhood of the last rib as a firm object 

 lying against the abdominal wall and moving in concert with 

 tlie respirations. Far more frequently in cattle the upper bor- 

 der of the enlarged liver can be felt by pressing inwards with 

 the fingers behind the last rib. In carnivora and emaciated 

 swine the liver can be felt through the abdominal wall under 

 both costal arches, in calves and small ruminants under the 

 right costal arch only. The hepatic area is very susceptible to 

 pressure, animals experiencing difficulty and exercising great 

 care in turning. 



Fig. 68. Enlargement of the area of hepatic dulness in a cow due to chronic hepa- 

 titis. A. Normal area. B. Enlarged area. The dotted line marks the ])()sition of 

 the costal arch and the nund)ers indicate the corresponding ribs. The liver weighed 



14.6 kilos. 



An increase in the area of hepatic tlulness may be referred 

 without any further delay in carnivora, ruminants and swine, 

 to a somewhat pronounced enlargement of the liver. The same 

 holds good for the horse. In carnivora (figs. 69 and 70) the 

 enlargement extends downwards and backwards, usually reach- 

 ing the uml)ilical region. In ruminants (fig. 68) it extends 

 backw^ards and downwards to below the costal arch on the right 

 side, or into the anterior portion of the hollow of tlie flank. In 

 ruminants the normal area of dulness depends upon the qual- 

 ity of food in the stomachs and intestines. In the horse (fig. 

 67) in cases where the enlargement of the liver is considerable, 

 there is an area of dulness immediately behind the edge of the 



