Hepatic failure and hemochromatosis of Salers and Salers-cross cattle

Hemochromatosis is rare in domestic mammals. Five clinical cases and one pr eclinical case of hemochromatosis were diagnosed in Salers and Salers-cross cattle. Clinical disease developed between 9 and 22 months of age. Animals were healthy until weaning but then lost weight, developed rough hair coat s, and lost incisor teeth. In two animals, hemochromatosis was identified b y liver biopsy, biochemical evidence of hepatic injury, and/or elevated tra nsferrin saturation values. At necropsy, carcasses were thin, with firm dar k brown livers and lymph nodes, soft bones, and brown-colored small bowel. The principal histologic changes were hepatocellular siderosis and periport al, bridging, and perivenular fibrosis. Siderocalcinosis involved collagen, elastin, reticulin, and basement membrane components in liver, lymph nodes , spleen, duodenum, and kidney. Hepatic iron concentrations in clinically a ffected cattle were 1,500-10,500 mug/g wet weight (reference range for catt le = <300 <mu>g/g). Ultrastructurally, the heaviest intrahepatic deposition was in hepatocytes, which contained large intracytoplasmic siderosomes. Ir on deposition in bone was associated with osteopenia. Genetic analysis indi cated a common ancestral bull in the pedigrees of five of six affected catt le; no pedigree was available for the remaining animal. Four dams of five a ffected animals were phenotypically normal and had histologically normal li vers. Test mating of four cows to the ancestral bull resulted in a female c alf that developed clinicopathologic and histologic evidence of preclinical hemochromatosis by 40 days of age. It was not possible to establish the pa ttern of inheritance because of the small number of pedigrees from affected cattle.