Observations on hypervitaminosis A and hydropericardium in chicks.

Abstract Male chicks developed severe hydropericardium when fed a 20% tallow diet for the first four weeks of life followed by a tallow-free ration containing 3,250,000 I.U. of vitamin A per kilogram. A small incidence of moderate hydropericardium was found in chicks fed a tallow-free ration for the first four weeks, followed by a 33% tallow diet containing excessive vitamin A. Neither excessive vitamin A nor tallow (20% for the first or 33% for the second four weeks of life) produced the cardiac abnormality, when fed separately. Histopathological studies on the chicks with severe hydropericardium showed various lesions in the myocardium, brain and kidneys. All of these organs were edematous with diffuse cellular degeneration and infiltration with inflammatory cells. The lesions in the cerebellum were characteristic of a vitamin E deficiency.