Reticuloendotheliosis in Japanese quail

An outbreak of reticuloendotheliosis occurred in a flock of Japanese quail. The most striking and consistent lesion observed was a marked thickening and nodular formations along the digestive tract. Other organs were involved with varying degrees of frequency, with tumour masses being observed in the lungs, liver, spleen, heart, pancreas, caeca! tonsils, ovary, kidney, airsacs, thyroid glands, testes and sciatic nerves. The histological changes were characterized by proliferation of an extremely anaplastic mononuclear type cell in the affected tissues. The cells bore all the characteristics of neoplastic growth, with large bizarre nuclei, numerous mitotic figures, misshapen nucleoli, and prominent pleomorphic cytoplasm.