Effect of levamisole on the immune response of chickens to infection with Eimeria tenella.

The effect of levamisole on the immunization to coccidiosis in chickens was investigated. The protection to the challenge infection with Eimeria tenella was higher in those chickens immunized by inoculating a small number of oocysts of E. tenella and administered orally with levamisole at dosage levels of 1.25 to 5 mg/kg body weight, once daily for 3 days, one week after immunization than in immunized and levamisole-untreated or unimmunized and levamisole-treated chickens. The activities of peritoneal macrophages of chickens from the immunized and levamisole-treated group were higher than those of chickens from the other groups. Furthermore, serum antibody titers and the leucocyte migration inhibitory factor-inducing activities measured in immunized and levamisole-treated chickens reflected the immune state of chickens.