Stages in the Life Cycle of Eimeria tenella Affected by Nicarbazin

Abstract

THE increasing use of coccidiostats for some time has stimulated interest in the way in which these compounds affect the parasites. Goff (1941), and Goff and Upp (1943) reported that sulfur affected the sporozoites of Eimeria tenella. Farr and Wehr (1947) showed the second generation schizonts and their contained merozoites to be the stages most susceptible to sulfamethazine. The anticoccidial activity of nicarbazin against E. tenella infections in chickens has been clearly demonstrated. Little attention has been given, however, to the specific reaction of the parasite to this drug, or to the stage or stages of the coccidian life cycle upon which nicarbazin exerts its effect. The experiments discussed in this report were designed in an attempt to determine the stage or stages of the life cycle of E. tenella affected by nicarbazin when the drug was fed to chicks which had been experimentally infected with this parasite.MATERIALS AND …