Miscellaneous Equine Liver Conditions.

Miscellaneous equine liver conditions not covered in other chapters include chronic active hepatitis, Tyzzer's disease, seasonal idiopathic hepatitis, neoplasia, and idiopathic persistent hyperbilirubinemia. Chronic active hepatitis refers to inflammatory and fibrotic liver disease with an unknown cause. Treatment is aimed at reducing inflammation. Tyzzer's disease is caused by Clostridium piliforme infection and causes acute necrotizing hepatitis in foals. Successful treatment with antimicrobial therapy and supportive care is rare. Seasonal idiopathic hepatitis is a winter disease of Midwestern horses. The cause is unknown but the prognosis is excellent with supportive care. Primary hepatic neoplasia and idiopathic persistent hyperbilirubinemia are rare.