Characteristics of Eimeria species

Eimeria species are highly host-specific so different species will infect chickens, turkeys and game birds with limited cross-infection (1).  Regardless, each species is unique in terms of level of pathogenicity and location of infection along the host intestinal tract. While each species can infect their host separately, they can also infect a bird simultaneously. In the field, birds are usually infected with more than one Eimeria species (2).  Scroll down for chicken, turkey and game bird Eimeria species.

normal intestine

Figure 1. Normal poultry intestine with important sections and markers labelled (3, 4).

Chicken Eimeria species

Nine Eimeria species have been described for chickens but only five to seven species (E. acervulina, E. brunetti, E. maxima, E. tenella, E. necatrix, E. praecox, E. mitis) are commonly associated with disease in commercial production (3).

chicken coccidia and lesions

Figure 2. Five chicken Eimeria species commonly associated with disease. Eimeria oocysts, location of infection along the intestine and lesions per species are shown (3, 5).

Turkey Eimeria species

Seven Eimeria species have been described for turkeys but only five species (E. adenoeides, E. meleagrimitis, E. meleagridis, E. gallopavonis and E. dispersa) are encountered commonly in commercial turkey production (6).  Eimeria adenoeides and E. meleagrimitis are considered the most economically important species contributing to coccidiosis in turkeys.

turkey coccidia and lesion pictures

Figure 3. Five turkey Eimeria species commonly associated with disease. Eimeria oocysts, location of infection along the intestine and lesions per species are shown (5, 7, 8).

Game Bird Eimeria Species

The Eimeria species of game birds (e.g. pheasant, chukars or bobwhite quail) have not been researched in detail like chicken or turkey Eimeria species.


1. Fayer, R. Epidemiology of protozoan infections: the coccidia. Veterinary Parasitology 6:75-103. 1980.

2. Williams, R.B. A compartmentalised model for the estimation of the cost of coccidiosis in the world's chicken production industry. International  Journal of Parasitology 29:1209-1229. 1999.

3. Reid, W.M., and P.L. Long. A diagnostic chart for nine species of fowl coccidia. College of Agriculture Experiment Stations, University of Geogia. 1979.


5. Thank you to Dr. Jean-Michel Reperant for chicken Eimeria oocyst photos and E. meleagrimitis lesion photo

6. Chapman, H.D. Coccidiosis in the turkey. Avian pathology 37:205-223. 2008.

7. Reid, M.W., P.L. Long, and L.R. McDougald. Coccidiosis. In: Diseases of Poultry, 8 ed. M.S. Hofstad, B.W. Calnek, M.W. Reid and H.W. Yoder Jr., eds. Iowa State University Press, Ames, Iowa, USA. pp 692-717. 1984.

8. Thank you to Ms. Shiem El-Sherry for the turkey Eimeria oocyst photos and E. adenoeides, E. gallopavonis and E. meleagridis photos