Clazuril is benzene-acetonitrile derivative, developed by Janssen Pharmaceutica as an anticoccidial agent for the treatment of pigeons. The anticoccidial effect is due to a cidal effect on the endogenous stages of the Eimeria species.

Ponazuril, sold by the Bayer Corporation under the trade name Marquis, was the first FDA-approved treatment for equine protozoal myeloencephalitis (EPM) in horse, caused by Sarcocystis neurona. Also this drug was used in animals such as cats, dogs against coccidia, an intestinal parasite. Coccidia treatment is far shorter than treatment for EPM.

Diclazuril is a main component of veterinary drugs used for the treatment of coccidiosis (chickens, turkeys, rabbits, etc) and equine protozoal myeloencephalitis (horses). When used for the treatment of coccidiosis, it acts by causing the degeneration of schizonts and gamonts. While in the animals affected by protozoal myeloencephalitis the drug is believed to inhibit merozoite production. In vivo experiments on horses have shown that the drug may cross the blood brain barrier.

Toltrazuril (Baycox, Procox, Tolcox, Toltrazuril) is a veterinary drug approved in Europe for the treatment of parasitic infections caused by roundworms and coccidia. In dogs it is used in combination with emodepside (Procox).