Pet Columns, Office of Public Engagement, College of Veterinary Medicine at the University of Illinois at Urbana-Champaign

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Fungal Infection Can Invade Dog's Body

Pet Column for the week of November 20, 1995

Office of Public Engagement
2001 S. Lincoln Ave.
Urbana, Illinois 61802
Phone: 217/333-2907
By Linda March
Information Specialist

Blastomycosis is a fungal infection that affects primarily young, male dogs that have access
to the outdoors.
According to Dr. Brendan McKiernan, a small animal veterinarian formerly at the University of
Illinois College of Veterinary Medicine at Urbana, "'Blasto' is a fungus that invades the
dog's body. If left untreated it can lead to the death of the dog."
Blasto is thought to be found in the soil, especially in the Great Lakes area, the Ohio,
Mississippi, and the Missouri River Valleys. The spore form of the fungus lives in the
environment. From there it is inhaled into the alveoli of the dog's lungs. Depending on the
animal's immune system and the amount of spores inhaled, the dog may either clear the
infection or it will spread throughout the body.
A dog infected with blastomycosis can show many signs. The dog may have a fever, lose
weight, and go off feed. Respiratory signs are most common, including coughing and
respiratory distress. The dog may also have skin lesions and draining open sores. These
skin lesions are often ulcerated and have a clear to bloody discharge. The eyes, male
genitals (prostate and testicles), and bones may also be affected.

"The dog's eyes should be watched carefully," Dr. McKiernan warns. "Blastomycosis can
cause rapid changes in the eyes. Pain, swelling, redness, excessive tearing, clouding of the
corneas, and even blindness may result from this fungal infection."
To detect blasto, your veterinarian may want to radiograph the lungs in addition to looking
at samples of skin lesion drainage under a microscope. By looking at exudate (discharge)
from a draining tract or an aspirate of a swollen lymph node under the microscope, your
veterinarian may see the actual yeast form of the fungus. If the dog is lame or sore in any
limb, radiographs may be helpful to show the bone changes that blasto can cause.
Blastomycosis demands aggressive treatment. Two drugs are currently used, one given
intravenously and the other orally. Potential side effects of treatment can include kidney and
liver toxicity. Methods exist to minimize these problems.
Dr. McKiernan notes, "It is very important to monitor the patient's kidney function. If the
kidney function becomes compromised, the treatment is stopped until the kidneys return to
If you have any questions about blastomycosis, call your veterinarian.