Etiology:  Eimeria falciformis, Eimeria hansonorum, Eimeria ferrisi are coccidia of mice.

Incidence: Incidence of infection is rare.  Young animals are primarily affected.

Transmission: Fecal-oral transmission via ingestion of sporulated oocysts. Oocysts require 1-3 days in an oxygenated atmosphere to sporulate.

Distribution:

E. falciformis: small intestine

E. ferrisi: cecum

E. hansonorum: small intestine

Clinical signs: Clinical signs range from none to enteritis which results in anorexia, diarrhea and sometimes death.  Eimeria are often part of a multifactorial disease.

Relative pathogenicity:

E. falciformis > E. ferrisi, E. hansonorum

Diagnosis:  Fecal flotation. Oocysts must be sporulated to spectate. Induce sporulation with time in a moist, oxygenated atmosphere or with 2.5% potassium dichromate solution.

Diagnostic morphology:

E. falciformis: 14-26 x 11-24 µm +/- polar granule; small steida body. No residuum or micropyle.

E. hansonorum: 16-18 µm, with a broad steida body.

E. ferrisi: 16-18 µm, with a small steida body.