Copper toxicosis in 3 Japanese Black cattle with chronic cholangiohepatitis.

Three Japanese Black cattle raised in different farms died suddenly with severe jaundice and hemoglobinuria. Gross examination revealed diffuse hepatic discoloration and highly viscous bile in the gallbladder. Histologically, the livers showed chronic cholangiohepatitis with hepatocellular vacuolation, bile plugs, interlobular bile duct hyperplasia, and periportal fibrosis. Alcian blue-periodic acid-Schiff staining showed acidic mucin in the bile ducts. Rhodanine staining and metallothionein immunohistochemistry demonstrated copper accumulation mildly in hepatocytes and mainly in Kupffer cells, and hepatic copper concentrations were markedly elevated (901-1,766 ppm). No histological evidence of infectious etiology was identified. Although these findings resembled dietary copper toxicosis, sporadic occurrence and severe cholangiohepatitis suggested that impaired biliary copper excretion may have played a role in the pathogenesis.