Beagle dog 90-day oral toxicity study of a novel coccidiostat – ethanamizuril

Background: Triazine coccidiostats are widely used in chickens and turkeys for coccidiosis control. Ethanamizuril is a novel triazine compound that exhibits anticoccidial activity in poultry. This study evaluated the subchronic toxicity of ethanamuzuril in beagle dogs administered ethanamizuril by diet at doses of 12, 60 or 300 mg/kg/day for 90 days. Results: : Ethanamizuril was well tolerated at low and middle dosages and in these dose groups there were no ethanamizuril related effects on survival, clinical observations, clinical pathology parameters, organs weight, macroscopic or microscopic evaluations. The ethanamizuril related changes were limited to effects on food consumption and histologic changes of kidneys in the 300 mg/kg/day group in both sexes. However, renal lesions resolved in dogs given ethanamizuril at 300 mg/kg/day when evaluated four weeks after the end of exposure. Conclusions: : Therefore, the no-observed-adverse-effect level (NOAEL) was considered to be 60 mg/kg/day, the middle dosage level tested. These results add to the safety database for ethanamizuril with potential for use as a novel coccidiostat.