What Is Nasal Aspergillosis?
Nasal aspergillosis is an infection of the nasal passages and sinuses by molds in the genus Aspergillus (most often A. fumigatus). In dogs it usually stays localized in the nose rather than spreading through the body. The fungus thrives on damp organic material outdoors; dogs inhale spores, and in some individuals the mold colonizes the nasal mucosa and bone, causing destructive inflammation.
Long-nosed (dolichocephalic) breeds such as German Shepherds, Retrievers, Collies, and sighthounds are over-represented. Cats more often get a different pattern of aspergillosis (including sino-orbital disease), so this page focuses on the common canine nasal form. Chronic sneezing and nasal discharge that do not clear with ordinary antibiotics should raise suspicion.
Why it matters
Left untreated, nasal aspergillosis can destroy turbinate bone and, rarely, threaten structures near the brain. Targeted antifungal therapy — often applied into the nose — usually works better than oral drugs alone.
Signs Owners Notice
- Chronic sneezing, reverse sneezing, or nasal congestion lasting weeks to months
- Nasal discharge that is mucoid, bloody, or one-sided; epistaxis (nose bleeds)
- Pain or sensitivity around the nose and face; rubbing the muzzle on furniture
- Depigmentation or ulceration of the nostrils in some cases
- Reduced smell, noisy breathing, or facial deformity in advanced disease
Causes and Risk
Risk factors include outdoor exposure to moldy environments, prior nasal trauma or foreign bodies, and possibly local immune factors in the nose. Systemic immunosuppression is a bigger theme in disseminated aspergillosis (a separate, rarer syndrome) than in typical nasal disease. Young to middle-aged dogs of long-nosed breeds are classic patients.
Owners often cycle through allergy treatments, saline rinses, or short antibiotic courses before someone considers fungal disease. Red flags that push the workup forward include discharge that is always worse on one side, repeated nosebleeds without trauma, and pain when the muzzle is touched. Outdoor dogs that dig under decks, root in leaf piles, or hang around barns and hay storage get more spore exposure than couch-potato pets.
Systemic (disseminated) aspergillosis is a different, more serious illness that usually needs different drugs and staging. If your dog has nasal signs alone, your vet will still examine lymph nodes and overall health, but the treatment path for classic nasal disease centers on cleaning and treating the nose itself.
Diagnosis
Routine antibiotic courses often fail. Veterinary workup may include imaging (CT is preferred), rhinoscopy to see plaques and turbinate damage, fungal culture or PCR, and cytology/biopsy. Blood serology can support suspicion but is not definitive alone. Your vet will also rule out nasal tumors, foreign bodies, tooth root disease, and other fungal infections.
Treatment and Outlook
- Topical antifungal therapy: clotrimazole or similar agents infused into the nasal passages under anesthesia after debridement — often the most effective approach
- Oral antifungals: sometimes added for residual or invasive disease
- Supportive care: pain control, treating secondary bacterial infection, and rechecks with imaging or scoping
Many dogs improve substantially after one or two topical treatments; some need repeat therapy. Prognosis is generally good for localized nasal disease when treated promptly. Costs in the US often run into the low-to-mid thousands when CT, anesthesia, and topical therapy are required.
Practical Tips for US Pet Owners
- Do not ignore weeks of one-sided nasal discharge or repeated nosebleeds.
- Avoid letting dogs dig in moldy compost, hay, or damp wood piles when possible.
- Ask about referral to a practice that performs rhinoscopy and topical antifungal infusion.
- Find veterinary clinics through veterinary clinic listings.
When to see a vet
Schedule promptly for chronic sneezing with bloody or one-sided discharge. Seek urgent care for heavy nosebleeds, sudden facial swelling, or neurologic signs (rare but serious).
Key Takeaways
- Nasal aspergillosis is a fungal infection of the dog’s nose and sinuses.
- Chronic sneezing, discharge, and nosebleeds are typical; long-nosed breeds are at higher risk.
- Topical antifungal treatment under anesthesia is often more effective than pills alone.
FAQ
Is nasal aspergillosis contagious to people or other pets?
People and pets are usually exposed from the environment, not from living with an infected dog. Household transmission is not the main concern.
Will antibiotics cure it?
Antibiotics may temporarily help secondary bacteria but do not clear the fungus.
Can it come back?
Yes. Relapse can occur; follow-up exams matter if signs return.