Blastomycosis in Dogs

Blastomycosis is a systemic disease caused by a fungus present in the soil of certain regions, such as Mississippi, Missouri and Ohio River Valley. The organism is present in the soil and infection occurs by inhalation of the fungus. Once infection is established in the lung, the fungus changes its characteristics by converting from the mycelial form into the yeast form and spreads to other organs causing a disseminated infection.

This fungus exists in two different forms:

Mycelial form. This form is present in the environment and is contagious. 

Yeast. This form is found in the tissues and is not contagious.

Hunting dogs that spend a lot of time outdoors and live in endemic areas are at risk for inhaling this organism and developing the disease.

Some animals may be infected but not show clinical signs for a long time. These animals are not a risk for contagion of other animals and people because the stage of the organism present in the animal's tissues is not that of an infectious stage.

If left untreated, these dogs can become seriously ill. Dogs may develop infection in the kidneys, eyes, brain and bones. According to the organ that is affected, the clinical signs may vary. They may have ocular problems or neurological signs like seizures and head tilt. In some dogs lameness may be the primary complaint due to infection in the bones.

What to Watch For

Coughing

Difficulty breathing

Fever

Loss of appetite

Weight loss