THE DIGESTIVE SYSTEM 65 



fibrous tissue occurs in the interlobular tissue only. 

 This newly formed fibrous tissue later contracts, thus 

 diminishing the size of the affected lobules, and there- 

 fore the liver as a whole. This condition is termed 

 atrophic sclerosis. Such a liver usually has an irregular 

 outline (hobnail liver) and is smaller, denser, and lighter 

 in color than a normal liver. It is possible that hyper- 

 trophic sclerosis, or the formation of new fibrous tissue 

 throughout the entire liver lobule, follows when the irri- 

 tant is introduced through the portal vein, and atrophic 

 sclerosis occurs when the irritant is introduced through 

 the hepatic artery. 



Symptoms. Hepatic sclerosis has an insidious onset. 

 Probably the first evidence of the disease is digestive 

 derangement, which later may be accompanied by 

 icterus. The animals become unthrifty and finally 

 weak and emaciated. 



Treatment. Remove the cause and prevent further 

 progress of the disease. A strict diet and the main- 

 taining of a laxative condition of the bowel may permit 

 the affected animals to be gotten into condition for 

 slaughter. 



Tumors 



Hepatic tumors are frequently observed by veterinary 

 inspectors in abattoirs, but these tumors are rarely of 

 sufficient magnitude to have produced visible symptoms 

 in the animal prior to slaughter. 



The various kinds of tumors that have been observed 

 in the liver of swine are true to the type for the same 

 tumors in other animals. The malignant tumors of the 

 liver frequently are found to be secondary. Of the 

 types of liver tumors the following have been identified, 

 lipoma, myxoma, angioma, sarcoma, adenoma, epi- 

 thelioma, and carcinoma. 



No definite symptoms of hepatic tumors can be 

 described; often there is no outward evidence. There 

 may be digestive disorders, emaciation, and evidence of 

 malnutrition. 



