B. Hepatitis

Clinical Findings. The cardinal signs of hepatitis are anorexia, mental depression, with excitement in some cases, muscular weakness and jaundice but in the terminal stages somnolence, recumbency and coma with intermittent convulsions. Animals which survive the early acute stages may evidence photosensitization, a break in the wool or hair leading to shedding of the coat and susceptibility to metabolic strain for up to a year.

The initial anorexia is often accompanied by constipation and punctuated by attacks of diarrhea. Vomiting may occur in pigs. The nervous signs are often pronounced and vary from lethargy with yawning, or coma, to hyper excitability with muscle tremor, mania and convulsions. A characteristic syndrome is the dummy syndrome in which we may observe the affected animals, pushing with their heads making no response to normal stimuli and blindness. There may be subacute abdominal pain usually manifested by arching of the back, and pain on palpation over the liver. The enlargement of the liver is usually not palpable.

Jaundice and edema may or may not be present and are more commonly associated with the less acute stages of the disease. Photosensitization may also occur but only when the animals are on a diet containing green feed and are exposed to sunlight. A tendency of bleeding more freely than usually it may be observed. In chronic hepatic fibrosis the signs are similar to those of hepatitis but develop more slowly, and persist for longer periods, often months. Ascites and the dummy syndrome are more common than in hepatitis.