While humans often become infected, dogs are still 10 times more likely to develop the disease than people are. A big factor in determining which dogs or people get infected is directly related to their lifestyle and where they live. People that spend time in the woods, as well as their dogs are much more likely to become infected. If they travel in swamps or near water they are at an even greater risk. Hunting dogs and hounds are therefore infected much more frequently than house pets in a given geographic area.
Infection occurs from the dog inhaling the spores that are found in the soil.
The spores then travel down into the airways of the lungs and an infection develops. It has been suggested that some infections could occur through a wound in the skin, but this source of infection is thought to be very rare. Once Blastomycosis establishes itself in the lungs, it then spreads throughout the body to different locations. The most common sites for infections after the lungs include the skin, eyes, bones, lymph nodes , subcutaneous tissue, brain and testes. The symptoms of blastomycosis in dogs include lack of appetite, weight loss, coughing, eye problems, lameness or skin problems.