“…Cyclophosphamide has been used experimentally in poultry as an immunosuppressive agent (Lerman and Weidanz, 1970;Glick, 1971Glick, , 1986Linna et al, 1972;Rouse and Szenberg, 1974;Sharma and Lee, 1977;Nathanson et al, 1981;Fadly et al, 1985;Ficken and Barnes, 1988;Corrier et al, 1991). However, at the dosages used, CPA lacks specificity in birds because lymphocytes, thrombocytes, and heterophils have all been shown to be affected (Lerman and Weidanz, 1970;Glick, 1971Glick, , 1986Linna et al, 1972;Rouse and Szenberg, 1974;Sharma and Lee, 1977;Nathanson et al, 1981;Fadly et al, 1985;Ficken and Barnes, 1988). In mice, 5-FU at specific doses has been shown to have a dramatic and specific effect on the circulating neutrophil population (Moore and Warren, 1987;Shimamura et al, 1987;Mclntyre et al, 1989).…”