Anticoccidial drugs are widely used as additives in feed and as veterinary drugs for the prevention and treatment of coccidiosis in poultry and other animals. The economic damage caused by coccidiosis in modern poultry production is so serious that practically all poultry farms have resorted to feeding anticoccidial drugs as a feed additive to pullets and broiler breeders for 12 to 16 weeks and to broiler chickens for almost their entire life.