Isospora sp from ducks. Infectivity for the goose, four anatids and the domestic fowl.

A coccidium was isolated from mule duck farms, the sporulated oocysts of which most closely resemble that of Isospora anseris, a goose coccidium. By experimental infection, these oocysts were proved to be able to develop in the goose and in several duck species, but unable to develop in the chicken. No pathogenicity was noted in any species.