Sarcocystis wapiti sp. nov. from the North American wapiti (Cervus elaphus)

Abstract

Sarcocystis wapiti sp. nov. (Eimeriina: Sarcocystidae) is described as a heteroxenous coccidian with dogs (Canis familiaris) and coyotes (Canis latrans) as the final hosts and wapiti (Cervus elaphus) as the natural intermediate host. Sarcocysts in various muscle tissues of the wapiti were micro- to macroscopic, had a thin primary cyst wall and septa, and measured 652 × 322 μm. Sarcocysts contained numerous bradyzoites that were 16.1 × 2.4 μm and few metrocytes that were 11.2 × 4.6 μm. Ten days after ingesting Sarcocystis-infected wapiti meat, a dog and a coyote began passing oocysts and sporocysts in their feces; a domestic cat did not pass oocysts or sporocysts after ingesting infected meat from the same animal. Sporulated oocysts measured 20.3 × 15.6 μm; sporocysts were 15.9 × 10.6 μm. Twelve days after ingesting wapiti meat, oocysts of S. wapiti were found in the lamina propria of the distal one-third of the villi of the small intestine of the coyote. Bradyzoites were found in digests of muscle tissue of 58 of 65 wapiti.