Supportive evidence by field testing and laboratory experiment for a new hypothesis of the ecology and pathogenicity of canine blastomycosis

This paper offers evidence showing that the pathogenicity of Blastomyces dermatitidis involves the following: 1. Infection with B. dermatitidis in dogs is very severe. Among 33 infected dogs almost 20% died, all but one with eye lesions. In addition, 70% developed skin lesions in the first 66 weeks of observation. 2. The skin test appears to be a useful tool in defining dogs probably infected with B. dermatitidis. 3. Serologic tests do not appear useful as indicators of infection because cross reactions with histoplasmin are frequent. 4. Field skin testing of dogs with blastomycin and histoplasmin indicates that it is extremely useful in detecting infected dog packs and premises. Almost half of more than 100 dogs in the area of the only known blastomycosis epidemic in North Carolina showed specific blastomycin tests as contrasted with an 11–18% rate in mongrel dogs in Kentucky. Skin testing of 20 fox hound packs in Kentucky has revealed 8 premises where 35% or more of the dogs show positive specific blast...