Aspergillosis in Dogs and Cats
Aspergillosis is a fungus that is very common in the environment and grows on old food, organic matter, and in the soil. There are over 180 species of aspergillosis and they rarely cause disease unless the dog or cat has a compromised immune system or is exposed to a very large amount of fungus. In most cases, the fungal infection will be confined to the nose/sinus region in dogs or sinus/orbit region in cats, but it can spread to other parts of the body in severe cases. Continue reading to learn more about this type of fungal infection, symptoms, testing, and treatment.
How can my pet be infected with aspergillosis?
The aspergillosis fungus releases spores into the environment that are spread around by air currents. When the spores are inhaled, they can potentially start to grow inside the sinuses or move to other areas of the body.
Dogs that are sniffing around are at a higher risk of developing this type of infection. Long-nosed dogs, such as Dachshunds, Collies, and Greyhounds, may be more likely to become infected. Retrievers and Rottweilers are also over-represented.
Symptoms of Aspergillosis Infection in Dogs and Cats
In dogs, this fungal infection typically involves the nose and sinuses. Clinical symptoms include:
- Nasal discharge, often from just one nostril
- Intermittent nose bleeds
- Destruction of the tissue of the nose (sores, tissue loss)
- Pain around the nose region
In cats, this fungal infection tends to infect the sinuses and region around or behind the eye. Clinical symptoms include:
- Nasal discharge, often from one nostril
- Protruding or enlarged eye
- Redness to the tissue around the eye
- 3rd eyelid elevation
- Oral mass or ulcer on top of the mouth
- Enlarged lymph nodes on the face below the jaw
- Neurologic symptoms including seizures, nystagmus, facial twitching, blindness, circling
In the more severe, but very rare, form of disseminated aspergillosis, the fungal infection can spread to other areas of the body including the bones, muscles, prostate, kidneys, liver, spleen, pancreas, brain/central nervous system, joints, intervertebral discs, eyes, lymph nodes, and pericardium. Since so many parts of the body can be infected, symptoms in dogs can vary widely from lethargy, vomiting, progressive lameness, changes to the eyes, neurologic issues, etc.
In cats with disseminated aspergillosis, symptoms may include anorexia, coughing, abnormal breathing, abdominal pain, diarrhea, and neurologic deficits.
How can my vet test for aspergillosis?
Testing for aspergillosis is not always easy and your vet needs to get 2 tests with supportive results to confirm the infection.
- Radiographs (x-rays) of the skull and sinuses, MRI or CT scan, or nasal rhinoscopy are all good options. CT and MRI are more accurate at finding changes/damage caused by the fungus than radiographs but are not available at many private practices. Rhinoscopy involves directing a tiny camera into the sinus/nasal area and actually seeing the fungus or damage it’s created. In cats, an ultrasound of the area behind the eye may reveal a mass effect and a sample may be obtained to confirm fungus is present.
- Imaging of larger areas of the body will be recommended if disseminated aspergillosis is suspected.
- Cytology of the nasal discharge occasionally shows the infective fungus.
- Fungal cultures of samples obtained from the sinus, typically obtained during rhinoscopy or ultrasound-guided aspiration, can confirm the infection. A fungal PCR can be run on these samples also.
- A biopsy sample from the sinus can be submitted to the lab to look for fungal organisms. The biopsies are often obtained during rhinoscopy.
My pet has been diagnosed with aspergillosis. How can they be treated?
Treatment often involves topical and oral medications. Oral antifungal medications often need to be given for months.
Topical treatment options include surgical placement of tubes into the sinuses and nose so medications can be applied directly to the site of the infection.
Another form of topical treatment involves your vet putting your pet under anesthesia and irrigating the sinuses and nasal passages with topical antifungals. This treatment is less invasive than surgically implanting the tubes and typically only needs to be repeated 1-2 times.
Surgical debridement of the affected tissues in the nose and sinuses can help improve medical treatment. Some dogs that were not cured with the more traditional treatments responded well to having a medicated bandage packed into the sinuses for direct treatment.
Dogs can have relapses 3 months to 5 years after treatment for oronasal aspergillosis.
For cats, oral or injectable antifungal medications are often needed, and a topical nasal antifungal may also be recommended. Treatment may be needed for 6 months or longer.
With the rare, but severe, disseminated aspergillosis, treatment is often needed for well over 6 months and the disease is very hard to cure.