Fungal Infections in Dogs
Fungi are parasitic organisms that produce spores and get their nourishment by absorbing food from their hosts. Though many species of fungus exist in the environment, only a few cause infections.
Soil is the cause of most infections in dogs, which occur through ingestion or inhalation. Infections can also invade the body through an open wound or cut in the skin.
While some fungal infections cause disease in animals that are otherwise healthy, others require a host that is immunocompromised or incapacitated (for example, an animal with poor nutrition, or illnesses such as cancer or viral infections may be at higher risk for infection).
Animals who have been under sustained stress or in captivity may also be at increased risk, as are those that require long-term use of immunosuppressive or antimicrobial drugs that may increase risk. An infection may be localized (systemic) or affect the entire body (generalized).
Common Fungal Infections in Dogs
Here are some of the most common fungal infections seen in dogs:
Aspergillosis
Aspergillus is a species of mold that can cause a fungal infection known as aspergillosis. Dogs can acquire it through their nose and sinuses and most commonly become infected with the nasal form of the disease, which could develop in other bodily organs. Dogs with weakened immune systems are most at risk for this infection.
Blastomycosis
This regional systemic fungal disease is found in the Great Lakes Region, along the Eastern seaboard, and in the Mississippi River valleys. Moist, organic debris and bird droppings can rot and become fertile ground for the fungus that’s commonly found in the area. If your dog inhales infected spores, it may start to exhibit symptoms.
Cryptococcosis
The yeast-like fungus cryptococcosis can infect dogs that inhale the spores found in soil that’s been contaminated with bird droppings.
Symptoms of Fungal Infection in Dogs
Symptoms of fungal infections in dogs can include:
Aspergillosis
- Nasal discharge
- Sneezing
- Swollen nose
- Bleeding from nose
- Decreased appetite
Blastomycosis
- Lameness
- Coughing
- Weight loss
- Eye problems
- Skin lesions
- Poor appetite
- Coughing
- Difficulty breathing
- Enlarged lymph nodes
- Fever
Cryptococcosis
This fungal infection can impact your dog’s lymph nodes, skin, eyes, and even the brain. Symptoms include:
- Circling
- Seizures
- Swollen lymph nodes
- Eye inflammation
- Blindness
- Imbalanced gait
- Coughing
- Lethargy
- Nasal discharge
- Eye problems
- Skin lesions
Other Fungal Infections in Dogs
Ringworm and yeast infections are other common fungal infections. Because ringworm is contagious and can spread to humans and other pets, it’s critical to have it treated early. Treatments can include medicated baths, dips, or oral antifungal medications.
Yeast infections originate from an overgrowth of yeast on a dog’s body, leading to discomfort and itching. Antifungal drugs or antiseptics can be applied to the skin to treat this infection. In severe cases, oral medications may be required. Unlike ringworm, yeast infections aren’t contagious to other pets or people.
Diagnosis and Treatment of Fungal Infections in Dogs
If you suspect your dog may have a fungal infection or other illness, they should see a vet as soon as possible. It may take several appointments to identify the cause of your dog’s symptoms, so the earlier symptoms are detected and addressed, the better.
Your veterinarian will complete a physical exam, then conduct specific tests to find out whether a fungal infection is a culprit and diagnose the issue.
Left untreated, fungal infections can result in pneumonia (blastomycosis) and other serious illnesses. Cryptococcosis can be particularly concerning as it can cause seizures, issues with your dog’s brain, and lead to a lung infection.
Aspergillosis and blastomycosis can be treated with antifungal medications such as itraconazole, fluconazole or ketoconazole.
Cryptococcosis can be difficult to treat, but imidazole-based medicines such as clotrimazole or miconazole may help. Your dog might have to be given oral antifungal medications for a year or more, and some will sadly succumb to this disease.
Note: The advice provided in this post is intended for informational purposes and does not constitute medical advice regarding pets. For an accurate diagnosis of your pet's condition, please make an appointment with your vet.