Chick embryo infections for the evaluation of anticoccidial drugs

Chick embryos have been infected with sporozoites of Eimeria tenella , but not with E. brunetti , and died from coccidiosis 5 days after infection. Chick embryos can be protected from death due to coccidiosis by some but not all drugs which give a therapeutic response in chickens. The system is therefore not satisfactory as a screening tool, but may have applications in studies on the nature of drug activity.