For the treatment and prevention of coccidial infections in lambs caused in particular, by the more pathogenic Eimeria species E. crandallis and E. ovinoidalis. To aid in the control of coccidiosis in calves caused by Eimeria bovis and Eimeria zuernii. Diclazuril is an anticoccidial of the benzeneacetonitrile group. The pharmacological studies performed in laboratory animals could not demonstrate pharmacological effects, other than the anticoccidial effect.

Dependent on the coccidia species, diclazuril has a coccidiocidal effect on the asexual or sexual stages of the development cycle of the parasite. Treatment with diclazuril causes interruption of the coccidial cycle and reduces excretion of oocysts for up to 14 days.