Avian leukosis in chickens: A Clinico-pathological survey

Abstract

A clinico-pathological survey of avian leukosis in naturally infected chickens was carried out in the present study organized poultry farms basing on clinical signs, gross, cytological and histopathological lesions in suspected tumour cases. Clinical signs of the affected chickens included emaciation, anorexia, decreased breeding potential and egg production. Necropsy revealed variable sized grey to yellow tumour like lesions on visceral organs such as liver, spleen, lungs, heart, kidney and ovaries. The lesions were more pronounced in liver characterised by nodular, miliary and diffuse type tumorous growths. Cytologically, impression smears revealed uniform sized lymphoblastic cells with thin rim of finely granular cytoplasm and a clear vesicular nucleus. Histopathologically, sections revealed extensive proliferation and infiltration of homogenous lymphoblasts cells in various organs with degree of degenerative changes. Lesions suggestive of avian leukosis were all observed in layer, mostly in Aseel breed. In one meat type bird, there was tumorous growth in the leg region.