Hypervitaminosis E in the chick.

BONE lesions have been described in animals given large doses of vitamin A. The bones are reduced in thickness and fractures are frequent (Moore, 1957). Much of this work has been done on the rat (Moore and Wang, 1945; Wolbach, 1947; Thompson and Pitt, 1960), but lesions have been described in other species including guinea-pigs (Wolbach, 1947), calves (Grey, Nielsen, Rousseau, Calhoun and Eaton, 1965) and man (Persson, Tunell and Ekengren, 1965). Rigdon, Rude and Bieri (1951) did not find lesions in the bones of hypervitaminotic ducklings but in contrast Wolbach and Hegsted found that hypervitaminosis A produced bone lesions in chicks (1952c) and in ducks (1953). Poumeau-Delille (1943) and Walker, Eylenberg and Moore (1947) recorded a marked reduction in the number of red blood cells in hypervitaminotic rats. The purpose of the work reported here was to investigate some aspects of the gross, histoand chemical pathology of hypervitaminosis A in chicks and to contrast the changes in bone with those observed in vitamin A deficient birds by Howell and Thompson (1967a, b).