A number of species infect rodents, including E. couesii, E. kinsellai, E. palustris, E. ojastii and E. oryzomysi.

The most prevalent species of Eimeria that cause coccidiosis in cattle are E. bovis, E. zuernii, and E. auburnensis.

[4] Eimeria infections are particularly damaging to the poultry industry and costs the United States more than $1.5 billion in annual losses.

[6] The oocysts of what was later called Eimeria stiedai were first seen by the pioneering Dutch microscopist Antonie van Leeuwenhoek (1632–1723) in the bile of a rabbit in 1674.

During the endogenous phase, several rounds of schizogony (asexual reproduction) take place, after which the sexual differentiation of gametes and fertilisation occurs.

[3] Once ingested, the oocysts undergo a process called excystation, whereby thousands of sporozoites are released into lumen of the intestine.

In the case of E. tenella, this process is thought to occur due to the combination of enzymatic degradation and mechanical abrasion of the oocyst wall in the chicken's gizzard.

[11] The motile sporozoites invade the enterocytes of small intestine, and migrate to their respective sites of development.

[12] After invasion, the sporozoites develop into trophozoites, then into schizonts, where they undergo several rounds of asexual reproduction.

When schizonts rupture, merozoites are released, which either go on to re-infect more enterocytes or develop into either male or female gametes via the process of gametogenesis.

Merozoite invasion also requires the formation of a moving junction, however the proteins involved in this process differs from those on sporozoites.

It is hypothesised that this may be due to the fact that merozoites are short-lived and a greater antigen repertoire would permit faster binding and invasion.

[13] Goussia (Labbe 1896): These species are tetrasporocystic, dizoic, lack Stieda bodies, and have sporocyst walls consisting of two valves joined by a longitudinal suture.

[16] Crystallospora (Thelohan 1893): The species in this genus is tetrasporocystic and dizoic, and have dodecahedral sporocysts composed of two hexagonal, pyrimidal valves joined at their bases by a suture.

[26] Diarrhoea may be bloody due to intestinal epithelium dying off when a large number of oocysts and merozoites burst out of the cells.

[29] Good animal husbandry practices and prophylactic application of anticoccidial drugs that target different stages of the parasite lifecycle, such as sulfonamides, ionophores and toltrazuril, are the preferred methods of disease prevention, particularly in the poultry industry.

[32] Humoral immunity is thought to play little role in protection, and is most likely mediated through secretory IgA antibodies.