Suppression of immunologic function and degeneration of lymphoid organs in cyclophosphamide-treated turkeys.

Neonatal administration of 8 to 20 mg of cyclophosphamide (CY) in turkey poults resulted in a marked alteration in the morphologic features of all major lymphoid organs. Cyclophosphamide induced severe deficiency in antibody response to multiple injections of Brucella abortus and sheep RBC and in vitro proliferative response of peripheral blood leukocytes to concanavalin A. The morphologic regeneration of thymus and of thymus-dependent areas was marked in all major lymphoid organs by posttreatment day 15. This regeneration preceded functional recovery of the mitogenic response of peripheral blood leukocytes. The regeneration of the bursa and bursa-dependent areas in other lymphoid organs was minimal through posttreatment day 27. Thus, CY may be used effectively in turkeys as an immunosuppressive reagent.