Experimental study of Eimeria robertsoni (Protozoa, Eimeriidae) in the snowshoe hare, Lepus americanus.

A 6 1/2-day prepatent period and a patent period of at least 22 days followed single oocyst infection of a young coccidia-free hare with Eimeria robertsoni. Size of oocysts increased significantly during patency and was negatively correlated with oocyst output. Oryctolagus cuniculus remained negative after inoculation per os of E. robertsoni of snowshoe hare origin.