Marek's disease in immunosuppressed chickens: growth of a transplantable lymphoma and development of the disease by natural exposure.

Evidence indicated that treatment of chickens with Cytoxan at hatching (bursectomy) had little effect on the development of transplantable Marek's disease (md) lymphoma. Cytoxan treatment of chickens at 2 and 3 weeks of age, however, apparently reduced the incidence of visceral tumors in chickens naturally exposed to MD. Amelioration of MD in immunosuppressed chickens was possibly mediated through suppression of MD-induced T-cell proliferation.