THE DIGESTIVE SYSTEM 63 



although the colon bacilli and its various derivatives 

 have been identified in the pus from liver abscesses. 



Lesions. The liver contains suppurative centers of 

 varying dimensions. The foci may occur throughout 

 the entire liver and be microscopic in size, causing' a 

 uniform enlargement of the liver, or the suppurative 

 centers may be as large as walnuts and appear as small 

 abscesses. The liver will be engorged with blood, more 

 friable than normal, and it may be variegated in color, 

 due to alternating small hemorrhagic areas and sup- 

 purative foci. 



Larger suppurative centers are gray in color and may 

 or may not be circumscribed by a capsule of fibrous 

 tissue. The content may be semifluid pus or it may be 

 caseous or even calcified. 



Symptoms. The evidence. of suppurative hepatitis 

 consists of general depression. The animal does not 

 move of its own volition. There is pain on palpation of 

 the abdomen (if abdominal walls are not too thick), and 

 icterus. Less extensive suppuration of the liver may 

 not produce any distinct symptoms. 



Treatment. The animal should be made as com- 

 fortable as possible and the evacuation of the bowel 

 content facilitated by the use of laxatives. 



Acute Interstitial Hepatitis 



Acute interstitial hepatitis is not a common con- 

 dition but it does occur in swine and therefore should 

 receive some consideration. 



Etiology. The cause of acute interstitial hepatitis 

 probably always enters the liver by way of the hepatic 

 artery, and is most frequently due to bacterial infection 

 or animal parasitic invasion. The various suppurative 

 bacteria, Bacillus coli communis or some of its derivatives 

 and Bacillus necrophorus, may be the causative agent. 

 Protozoan parasites and the larvae of some vermes are 

 responsible for some cases of acute interstitial hepatitis. 



Lesions. The liver is enlarged and appears to be 

 affected with chronic interstitial hepatitis because the 



