Marek's disease in Japanese quails (Coturnix coturnix japonica): a study of natural cases.

Marek's disease was observed in quails. Gross lesions were confined mostly to the spleen and liver. Microscopic lesions were commonly seen in spleen, proventriculus, liver, and duodenum. Skin, peripheral nerves, and other visceral organs were also involved. Of 123 quails examined, 39 had serum antibodies against Marek's disease. These antibodies were detected from 11 to 17 weeks of age; the highest incidence was recorded at 15 weeks. Feather follicular antigen detected in 30 of the 95 quails was comparable to that of chicken. The disease was experimentally reproduced in susceptible quails. Marek's-disease-tumor-associated surface antigens (MATSA) were demonstrated in the peripheral leukocytes and spleen cells of affected quails. The possible source of infection and its epidemiological importance are discussed.