Coccidiosis in Wisconsin Cottontail Rabbits in Winter

Abstract

Since coccidiosis is generally considered a disease of the warm months of the year, little research has been conducted on its importance and incidence in over-wintering hosts. Boughton (1937), in a study of Isospora infection in the English sparrow in Wisconsin, noted 100 per cent incidence of the coccidia in winter, while Fitzgerald (1959) noted in Utah cattle a decline in incidence from 95 per cent in November to 30 per cent in March. Preliminary sampling of fresh feces of the cottontail rabbit (Sylvilagus floridanus) in Wisconsin indicated that occasional large showers of oocysts occurred in the middle of the winter. To clarify the winter status of this disease, a fecal survey was made during the winters of 1959 to 1960, and 1960 to 1961 near Green Bay, Wisconsin. Although comparative data from the summer months are lacking, this short paper will explore the potential importance of winter infection in the epizootiology of this disease in wild cottontails.