A distinct type of liver disease is described in 21 cats. It is characterized morphologically by monolobular fibrosis, lymphocytic infiltrates which surround and permeate bile ducts and proliferation of bile ductules of varying intensity. The most common clinical signs are ascites, jaundice and hypergammaglobulinaemia. The condition appears to progress through an active stage of intense lymphocytic infiltration and proliferation of bile ductules to a stage of progressive monolobular fibrosis which results in distortion of liver architecture. The rate of progression is very variable.
The condition differs from that of ascending or suppurative cholangitis described in the cat and bears only superficial resemblances to various forms of cholangitis in man and other species. At present the aetiology is unknown but it is suggested that genetic and immunological factors may predispose certain animals to produce hepatic lesions after exposure to a variety of environmental factors.