Epidemiology of Canine Blastomycosis in Wisconsin

Abstract

An epidemiologic study was designed to investigate the increasing number of canine blastomycosis cases being reported in Wisconsin. From January 1980 through July 1982, 200 cases of canine blastomycosis from 39 Wisconsin counties were examined to assess epidemiologic and environmental aspects of this disease. Based on a survey of 176 dog owners, principal disease characteristics for canine blastomycosis were anorexia, lethargy, shortness of breath, chronic cough, and weight loss. High incidence areas of canine blastomycosis occurred in the southeast, central, northwest, north central and northeast regions of Wisconsin. The central and northeast regions are new enzootic areas defined in this study. Sporting breeds accounted for the largest percentage of cases among the various breeds of dogs in Wisconsin. The majority of cases occurred among dogs three years of age and under. There did not appear to be a sexual predilection of dogs with blastomycosis in this study. Canine blastomycosis cases occurred from late spring through late fall. Enzootic areas, except for the southeast region of Wisconsin, occurred in sandy, acid soils. Results of this study suggest a possible association of enzootic areas with waterways, especially impoundments. Serum sampling resulted in the identification of a positive serologic reactor to blastomycosis in an adult timber wolf (Canis lupis).