Sulfonamide and toltrazuril therapy of experimental turkey coccidiosis

Following experimental infection of caged turkeys with a mixed oocyst suspension of E. meleagrimitis, E. adenoeides and E. gallopavonis, the efficacy of sulfachlorpyrazine, sulfaquinoxaline + pyrimethamine, sulfaquinoxaline + diaveridine, and toltrazuril was investigated based on clinical and parasitological parameters. Infected turkeys developed severe clinical symptoms. Only weak symptoms were observed in those groups which were treated with the sulfa- and sulfa-DHFR-inhibitors. The toltrazuril-treated group remained free of clinical symptoms. At the 8th day after infection, the clinical lesions coincided with the intensity of the gut lesions together with parasitological findings based on microscopical examination of mucosal smears. The same coincidence was observed for parameters such as oocyst excretion and body weight development.