It can create a variety of respiratory, eye, and skin lesions but can usually be successfully treated if caught early enough. Blastomyces dermatididis is a fungal organism that lives in sandy, acidic soil in close proximity to water. Most competing soil organisms will kill off the blastomycosis spores unless the conditions are nearly perfect for the fungus to survive. This explains why blastomycosis is often found in small pockets instead of being widespread. The proximity to water appears to be very important.
Blastomycosis has a well-defined endemic area where it is found.
The area includes the Mississippi, Missouri, and Ohio River valleys, the Mid-Atlantic States and parts of Quebec, Manitoba, and Ontario. It is believed that the range of blastomycosis continues to grow. Blastomycosis is primarily a disease that infects people and dogs. While there have been reported cases in a wide variety of animals including cats, horses, and ferrets, they are relatively rare. While humans often become infected, dogs are still 10 times more likely to develop the disease than people are.