Coccidiosis, a protozoal disease of many mammalian, and all domestic livestock species, is caused by infection with species of the genera Eimeria or Isospora. Clinically it is characterized by enteritis although subclinical infections are frequent. The disease is relatively common in sheep, goats and cattle, rare in horses. The overall prevalence of coccidia was 47.1%, with the highest prevalence in <4 months old calves (51.8%) and the lowest in >12 months old cattle (27.0%). The immunizing effect of inactivated sporulated oocyst and inactivated sonicated vaccines against bovine coccidiosis was observed in calves. Indirect haemagglutination (IHA) test was developed for detecting antibodies to coccidian. Serum antibody levels in calves were measured against soluble oocyst (sporulated) antigen.