MICROSCOPIC LESIONS OF NATURALLY-OCCURRING AND EXPERIMENTAL SPIKING MORTALITY IN YOUNG BROILER-CHICKENS

Tissues from five chickens from each of 44 flocks affected with "spiking mortality" were examined histologically. Tissues from these chickens were characterized by: multifocal necrosis of hepatocytes with congestion and blood lake formation; severe lymphocyte necrosis in the bursal medulla, thymic cortex, and gut-associated lymphoid tissues; acute necrotic vasculitis in the alimentary serosa and liver; rickets; and air-sac disease in survivors. No specific etiology was identified in sections examined.