Atlas of livestock parasites
digitized collection of microscopical preparations

Atlas of Parasites Contents Information sources Glossary Administration

Eimeria spp. (cattle, sheep, goat)



Untitled document

Protozoa (coccidia)              


Distribution: Worldwide.   

Host: Many host-specifc species of Eimeria infect the intestinal tract of domestic  ruminants and camelids.            

Life Cycle: Fecal oocysts sporulate in the environment and infect intestinal cells following ingestion. Asexual and sexual reproduction is followed by the production of oocysts that exit the host in manure. Sporulated oocysts can survive for long periods under favorable environmental  conditions.        


Diagnosis: Oocysts are found on routine fecal fotation exam. Species identifcation is diffcult and, in most cases, requires microscopic exam of sporulated (infective) oocysts. Although the number of oocysts in the feces has been used as an indicator of clinical disease, high numbers of oocysts can also be present in the absence of clinical signs.

Size: Approximately 12–45µm in length (oocyst), depending on species             

Clinical features: Most ruminants become infected with coccidia at an early age, and low-level infection persists through adulthood. While infection is often subclinical, coccidiosis is a common cause of diarrhea in young ruminants. Signs range from mild diarrhea to severe, bloody diarrhea. Not all species of Eimeria are equally pathogenic.

Of 12 species of common bovine Eimeria, clinical disease is usually associated with E. bovis, E. zuernii, or, less commonly, E. alabamensis. Similarly, E. bakuensis, E. ahsata, and E. ovinoidalis are pathogenic ovine Eimeria species. In  goats, E. airlongi, E. caprina, E. ninakohlyakimovae, and E. christenseni have been associated with clinical disease.

Fewer species of coccidia have been described in camelids than in ruminants, but  they all have been reported to cause clinical disease. In the Northern America, E. macusaniensis is considered highly pathogenic in naive animals, including adults.


No picture to show.

<<< Back