ADENOVIRUS-INDUCED INCLUSION-BODY HEPATITIS IN 4-DAY-OLD BROILER BREEDERS

Two separate parent broiler flocks originating from the same grandpare nt dock experienced mortalities of 23% and 40%, respectively, in chick s between 1 and 14 days of age. Chicks affected at 4 days of age had t remors, depression, and hypoglycemia. They had pale yellow, swollen, f riable livers. Pancreata were discolored and hemorrhagic. Spleens were swollen and sightly darkened. Microscopic lesions consisted of multif ocal areas of acute hepatic and pancreatic necrosis with numerous baso philic intranuclear inclusions with karyomegaly. Splenic sections had severe lymphoid depletion and reticular cell and macrophage hyperplasi a. An adenovirus from affected livers was isolated in chicken embryo l iver cells. Serologic evidence suggests that the grandparent hock bega n egg production seronegative to adenovirus antibodies, was exposed du ring production, and, subsequently, shed adenovirus vertically to its progeny. The clinical syndrome was reproduced by injecting the isolate d adenovirus into 1-day-old antibody-negative chicks. Histologic lesio ns in the experimentally reproduced disease cases were identical to th ose in the naturally occurring cases.