Necrotizing myopathy associated with hemolytic anemia in owl monkeys (Aotus trivirgatus)

In 40 owl monkeys with hemolytic anemia of unknown etiology, 37 had a myopathy characterized by focal or diffuse necrosis of sarcoplasm which was eosinophilic and floccular. Phagocytosis of necrotic fibers and regenerative changes were also observed. The severity of lesions roughly paralleled the severity of anemia and of centrilobular hepatic necrosis assumed to be caused by hypoxia. That the myopathy was not caused by anemia per se was suggested by the finding of mild myopathy in 10 of 24 monkeys known never to have been severely anemic. Although anemic owl monkeys are known not to be deficient in either vitamin E or selenium, parenteral vitamin E is partially protective against hemolysis in this species. The myopathy, which resembled that caused by vitamin E or selenium deficiency in other species, is probably the result of a metabolic abnormality involving vitamin E in an unknown way.