Synonym: Eimeria aemula.
Hosts: Sheep, goat, Rocky Mountain bighorn sheep, Ovis ammon polii, 0. musimon, O. orientalis, Capra ibex, Rupicapra rupicapra (chamois), Ammotragus lervia (Barbary sheep).
Location: Small intestine.
Geographic Distribution: Worldwide.
Prevalence: This species is fairly common. Christensen (1938a) found it in 11% of 100 sheep from Idaho, Maryland, New York and Wyoming. Balozet (1932) found it in 21% of 63 sheep and 2% of 41 goats in Tunisia. Jacob (1943) found it in 40% of 100 sheep and 18% of 11 goats in Germany. Svanbaev (1957) found it in 43% of 302 sheep and 40% of 48 goats in Kazakhstan.
Morphology: The following description is based primarily on those of Christensen (1938a) and Balozet (1932). The oocysts are ovoid, 25 to 35 by 18 to 24 u, with a mean of 28.9 by 21.0 u according to Christensen or 31.5 by 22.1 u according to Balozet. The oocyst wall is transparent, delicate salmon pink to pale yellowish brown, 1 u thick at the most according to Balozet; with a faint, yellowish-green "external coat ... about half as thick as wall" according to Christensen. The micropyle is conspicuous, 2 to 3 u in diameter, at the small end. A micropylar cap is absent. An oocyst polar granule was illustrated by Balozet (1932). Oocyst and sporocyst residua are absent. The sporulation time is 1 to 2 days according to Christensen, 3 to 4 days according to Balozet.
Life Cycle: The life cycle of E. faurei does not seem to have been worked out in detail. According to Lotze (1953), its schizonts are about 100 u in diameter and contain thousands of merozoites.
Pathogenesis: This species is only mildly pathogenic. Lotze (1954) found that single infections of 3-month-old lambs with 5 million oocysts produced only a temporary softening of the feces without significantly affecting the general health or physical condition of the animals, and infections with 50 million oocysts failed to cause death.
Epidemiology: This species has been reported not only from the domestic sheep and goat but also from the Rocky Mountain bighorn sheep (Ovis canadensis), moufflon (O. ammon), urial or shapo (O. orientalis), Barbary sheep (Ammotragus lervia), ibex (Capra ibex) and chamois (Rupicapra rupicapra) (see especially Yakimoff, 1933). Whether the forms from these species are all E. faurei remains to be proven by careful study of their oocysts and cross-transmission experiments. According to Lotze (1953), no cross-transmission studies, even between domestic sheep and goats, had been reported up until the time of his paper, and he attempted none.