Aspergillosis in Cats: Nasal Signs, Eye Swelling and Treatment

By Dr Duncan Houston

Persistent sneezing or nasal discharge is often attributed to cat flu. If it does not resolve, or the face or eye changes shape, a deeper investigation is needed.

Aspergillosis is one possible cause. It is uncommon, but disease around the eye can threaten vision and extend into surrounding tissues.

Quick Answer

Feline aspergillosis is an infection acquired from environmental Aspergillus fungi, usually through inhaled spores. It may remain in the nose and sinuses or become invasive around the eye. Persistent nasal signs need a vet assessment, while a bulging or painful eye, sudden blindness, neurological signs or breathing difficulty need urgent care.

How does the disease differ between cats?

Sino-nasal disease affects the nasal passages and sinuses, causing discharge, sneezing and sometimes bleeding. Sino-orbital disease extends into tissues around the eye and may cause protrusion, third-eyelid elevation or facial swelling. Disseminated infection affects distant organs and is less common.

The ABCD feline aspergillosis guideline distinguishes these forms and the importance of identifying the organism. Persians and related short-faced cats are overrepresented in reports, but any cat may be affected. An otherwise apparently healthy cat can develop the disease; immune suppression is not required.

How urgently should you act?

What else could cause these signs?

Chronic rhinitis, dental disease, a foreign body, a nasal tumour and other fungal infections can resemble aspergillosis. A mass behind the eye may also be an abscess or cancer. Appearance alone cannot distinguish them.

A superficial nasal swab may pick up an environmental fungus without proving invasive infection. The vet needs to interpret laboratory findings with examination, imaging and tissue samples.

How is it diagnosed and treated?

CT imaging helps map nasal and orbital disease. Rhinoscopy allows direct examination and sampling. Cytology or histopathology looks for fungal involvement in tissue, while culture or molecular testing helps identify the species and guide treatment.

Treatment may combine removal of fungal material, locally administered antifungal medication under anaesthesia and prolonged systemic antifungals. Invasive orbital disease can require specialist procedures. Cornell's feline aspergillosis information explains why treatment and prognosis depend on extent. A plan used for a dog's nasal disease should not simply be copied for a cat.

What to do at home

1. Record discharge, appetite and any change in facial symmetry or vision.
2. Keep the cat calm and indoors while arranging assessment.
3. Give prescribed treatment consistently and attend monitoring appointments.
4. Report vomiting, food refusal or other possible medication effects promptly.
5. Do not stop treatment simply because sneezing improves; confirm the endpoint with the treating team.

Common mistakes

Avoid treating every chronic sneeze as routine cat flu, using leftover antifungals, putting household disinfectants into the nose, or dismissing an enlarged eye as simple conjunctivitis. Do not delay emergency care while trying steam or other home remedies for respiratory distress.

Can it be prevented?

There is no guaranteed prevention because Aspergillus spores occur widely in the environment. Remove mouldy bedding and decaying material, maintain ordinary household hygiene and manage underlying disease with your vet. These sensible measures do not eliminate risk.

Frequently Asked Questions

Is it contagious between cats?

It is generally acquired from the environment rather than ordinary contact with another affected cat.

Can a cat recover?

Some do, particularly with less invasive disease. Orbital or disseminated involvement makes the outlook more guarded.

Does a positive fungal swab prove infection?

No. Sampling site and evidence of tissue disease matter.

How long does treatment take?

Often a prolonged course with repeated assessment. The specific organism, disease extent and response determine duration.

Persistent nasal disease deserves a diagnosis. Eye swelling changes the urgency, and early specialist assessment can clarify the best options.

For more practical animal health information, explore ASK A VET™. Your own veterinary team can help tailor the next steps to your cat or dog.