“…Many of the older synthetic drugs did not completely prevent parasite development and were not fully effective against all species of Eimeria. Aklomide, amprolium, arprinocid, dinitolmide, glycarbylamide, nicarbazin, nitrofurazone, nitrophenide, Polystat, robenidine, trithiadol and zoalene were reported not to prevent immunity developing to various species HortonSmith & Long, 1952;Gardiner & Farr, 1954;Berg et al, 1956;Cuckler & Malanga, 1956;Edgar, 1958;McLoughlin & Gardiner, 1962;Karlsson & Reid, 1978). In the case of amprolium and nicarbazin, not all results were in agreement since several studies suggested that they either delayed or prevented the development of resistance against reinfection (Strout et al, 1958;McDougald & Reid, 1971).…”