Eimeria Media

Synonym: Eimeria flavescens.

Hosts: Domestic rabbit, California jack rabbit (Lepus californicus), cottontail (Sylvilagus floridanus), Wyoming cottontail (S. nuttallii grangeri).

Location: Thruout small and large intestines.

Geographic Distribution: Worldwide.

Prevalence: Quite common. Kessel and Jankiewicz (1931) found it in 12% of over 2000 rabbits in California.

Morphology: The oocysts are ovoid, smooth, 19 to 33 by 13 to 21 u. A micropyle is present. An oocyst polar granule is absent. An oocyst residuum is present. The sporocysts are elongate ovoid, with a Stieda body. A sporocyst residuum is present. The sporulation time is 2 days.

Life Cycle: Rutherford (1943) and Pellerdy and Babos (1953) described the life cycle of this species. The endogenous stages are found above or below the epithelial cell nuclei of the intestinal villi and also occur in the submucosa. There are 2 asexual generations of merozoites followed by microgamete and macrogamete production. Completion of the endogenous cycle takes 6 days, and the prepatent period is 5 to 6 days. According to Kheisin (1947), E. media produces 150,000 oocysts per oocyst fed.

Pathogenesis: This species is moderately pathogenic (Pellerdy and Babos, 1953). It may cause the usual signs of intestinal coccidiosis. The affected parts of the intestine may be edematous, with greyish foci.