Prevalence and geographic distribution of canine and feline blastomycosis in the Canadian prairies

This retrospective study reports patient signalment, method of diagnosis and geographic distribution, and examines trends in prevalence and seasonal distribution of blastomycosis cases submitted to a veterinary diagnostic laboratory in Saskatchewan over a 21-year period. Of the 143 cases that originated from Saskatchewan and Manitoba 137 were from canine and 6 from feline patients. Signalment was similar to that previously reported. All cases originated in southern Saskatchewan and Manitoba, primarily from Regina, Moose Jaw, Swift Current, and Winnipeg. Case numbers showed a significant increase in the period 2001 to 2010 compared to 1990 to 2000. Seasonally, there was an increasing trend in the number of diagnoses from February to November. There was no correlation between average seasonal temperature or average seasonal total precipitation and the number of cases of blastomycosis. The persistence of blastomycosis in southern Saskatchewan indicates that Blastomyces dermatitidis is now endemic in this region.