Distribution of Blastomyces dermatitidis in dogs with skin test and serologic results following airborne infection.

Reported is a short term (16 week) experiment to determine the distribution of B. dermatitidis in dogs when infected by the natural inhalation route by receiving about 250,000 viable particles during a 24h. exposure. Four dogs were positive to blastomycin and 1 to histoplasmin prior to exposure. Post exposure, all dogs developed positive skin tests to blastomycin by the 4th week with considerable cross reaction to histoplasmin. Serologic tests showed more poritive CF tests to Histoplasma than to Blastomyces so that the test appears of no practical value. Although 22 tissues were cultured on each dog, only 1 or 7 dogs was positive for B. dermatitidis by 2 weeks. At 4 weeks, 57% of the dogs were positive by culture and at 12, 15, and 16 weeks, all were positive. One dog developed eye lesions and became emaciated.