Cardiomyopathy and vitamin E deficiency in zoo animals and birds.
Cardiomyopathy associated with vitamin E deficiency was diagnosed in more than 100 ruminants and primates and in 106 embryos and newly hatched chicks and ducklings. Affected bird embryos failed to pip the eggshell and died inside. Newly hatched chicks and ducklings and neonatal ruminants were weak, had difficulty standing or rising, and died within a few days. Death usually occurred without premonitory signs of disease in juvenile and adult animals. On gross examination, the hearts of the neonatal ruminants had areas of mottled, pinkish-tan myocardium. The hearts of the embryos and newly hatched birds were edematous, pinkish, and pale. In the juvenile ruminants, irregular, whitish patches or pale areas were seen in the myocardium. Histologically, there was multifocal myocytolysis in the myocardium of the neonatal and juvenile ruminants and embryos and newly hatched birds. Focal disseminated or diffuse myocardial fibrosis and myocytolysis were observed in the hearts of the adult animals. Plasma alpha tocopherol values were low enough in all species to be considered deficient. These values increased significantly after the addition of alpha tocopherol and/or vitamin E to the diets of the animals. Cardiomyopathy has not been diagnosed in any of the same groups of animals since supplementation was initiated.