Epidemiological features and pathological study of avian leukosis in turkeys' flocks.

AIM: The purpose of this study was focused on the identification of tumor diseases in turkeys on the basis of a detailed description of epidemiological features, clinical signs, lesions, and histopathological changes.

MATERIALS AND METHODS: Outbreak of a tumor disease in turkeys was investigated in various regions of Eastern Algeria. Four turkeys' flocks aged from 17 weeks were affected, resulting to mortality often over 10%, on a period of 15 days. The main epidemiological characters, clinical signs, and lesions were observed throughout all the course of the disease. Serum samples were collected from affected turkeys in each flock to detect p27 antigen in enzyme-linked immunosorbent assay (ELISA) test to diagnose avian leukosis virus (ALV). Portions of sciatic nerves and livers are taken from dead turkeys for microscopic examination.

RESULTS: The disease was characterized by clinical signs such as anorexia, weakness, and diarrhea. Necropsy of the dead birds showed hepatomegaly and gross splenomegaly with neoplastic nodules or gray foci and diffuse infiltration in the myocardium and lungs. ALV antigen test using ELISA confirmed the presence of virus leukosis. Histopathological sections of the liver had proliferations of lymphoblastoid cells and absence of any modifications or lymphocytic infiltration in peripheral nerves.

CONCLUSION: The present study confirms that this disease condition is caused by lymphoid leukosis.