Abstract
Seven mutant Southdown sheep, with congenital hyperbilirubinemia, 1 1/4–5 years of age, were necropsied. Gross lesions were yellow and green discolorations, testicular atrophy, radial renal fibrosis, pulmonary edema, hydrothorax, and ascites. Pigmentation was detected only in the teeth unless the sheep had been exsanguinated; light green bones, periosteum, fascia, serosa, tracheal and esophageal mucosae, and yellow intima of the aorta and endocardium were then visible. All lymph nodes showed mild lymphadenitis with hyperplasia of the reticulohistiocytic cells that contained bilirubin. Pigment (‘lipofuscin’) was present pericanalicularly in the hepatocytes without any zonal distribution. Seminiferous tubular degeneration resulted in reduced spermatogenesis. Most deaths were attributed to renal failure associated with renal radial fibrosis.