Myocarditis of probable viral origin in chickens

Severe nonsuppurative myocarditis with Feulgen-positive intranuclear inclusions in six adult White Leghorn chickens is described. Livers of three birds had mild to moderate centrilobular coagulative necrosis, with no inclusions. The myocardial intranuclear inclusions contained a large number of 18-to-20-nm particles; these are compared with members of the family Parvoviridae.