Coccidiosis in ruminants: the inevitable infection

摘要

Infection of ruminants by pathogenic Eimeria species is inevitable.' Oocysts are ubiquitous in the environment where animals are kept, and are capable of surviving for long periods of time, thus, all calves become infected sooner rather than later.1 The risk of infection is increased where stocking density is high or faecal material accumulates coinciding with optimal environmental conditions for oocyst survival. The risk of succumbing to disease is increased when infected animals are exposed to highinfectious pressure and management stressors at the same time.2The prevalence of Eimeria infection in cattle is high and can reach 100% in calves.WA5 Whether an animal develops clinical signs or is affected sub-clinically depends on the infectious dose, pathogenicity of species involved and the degree of concurrentstress factors prevailing.