The term describes changes in the nasal lining and discharge rather than identifying one pathogen. Viral infection commonly causes acute rhinitis in cats. Allergic rhinitis is possible but considerably less common than the list might suggest; irritation from dust or fragrance does not automatically mean allergy either.
When to see a vet urgently
Contact an emergency vet immediately if your cat has any of the following:
- Open-mouth breathing at rest.
- Visible respiratory effort or neck stretching to obtain air.
- Bluish or greyish mucous membranes.
- Collapse or severe weakness with respiratory signs.
Keep your cat calm while arranging transport. Do not watch breathing difficulty at home as ordinary rhinitis. You can find a vet near you.
Overview
Rhinitis results from inflammation of the nasal passage lining. Normal mucus protects and moistens the airways, but inflammation increases mucus, swells the lining and makes nasal breathing harder. In cats, this leads to breathlessness, reduced smell and poor appetite.
Not every cat with rhinitis is breathless. Congestion can cause snuffling and difficult nasal breathing without lung disease. However, obvious respiratory effort always needs urgent assessment, because nasal discharge alone does not identify where the breathing problem originates.
Nasal and sinus inflammation may occur together. Prolonged inflammation can damage normal mucosal function, allowing symptoms to persist after the original infection subsides. Recurrence then does not necessarily mean a new infection each time.
Causes
Common causes of catarrhal rhinitis include:
- Viral infections, including FHV-1 and calicivirus.
- Bacterial complications, including Bordetella and Mycoplasma.
- Allergic reactions to dust, pollen or household chemicals.
- Irritation from smoke or aerosols.
- Nasal foreign bodies.
- Injuries.
- Tumours, less commonly and with chronic nasal signs.
Clear discharge alone does not distinguish a virus from irritation or allergy. Mucus or pus alone does not establish bacteria as the primary cause either. Bacterial multiplication can follow other mucosal damage.
Persistent or one-sided signs also prompt investigation for foreign bodies, tooth root disease, fungal infection and tumours. Calling the symptom ordinary rhinitis does not exclude these. Herpesvirus can remain latent and reactivate with stress, for example. This does not mean every later sneeze is caused by herpesvirus.
Risk factors
Rhinitis is more common in cats that:
- Are kittens or unvaccinated young cats.
- Live in shelters or densely populated spaces.
- Have immune deficiency.
- Live in dusty or smoky environments.
- Have allergies.
The importance of exposure depends on the cause. Dense cat groups facilitate respiratory infection spread, but a solitary indoor cat can also have symptoms following an earlier infection. Allergy is not inferred from sneezing or indoor living; record the suspected irritant and timing of symptoms for investigation.
Symptoms
Catarrhal rhinitis causes:
- Clear or mucoid nasal discharge.
- Sneezing.
- Nasal congestion and whistling breathing sounds.
- Reduced appetite because food cannot be smelled well.
- Watery eyes and conjunctivitis, usually with viral infections.
- Apathy and mild fever in infectious rhinitis.
Monitor whether discharge comes from one or both nostrils and changes in amount or appearance. Sudden one-sided sneezing with face rubbing may raise suspicion of a foreign body. Persistent bloody discharge or swelling around the nose needs more thorough investigation. These signs cannot provide a definite diagnosis at home.
Squinting, keeping an eye closed or obvious eye pain warrants prompt contact. A respiratory infection may involve corneal damage that wiping eye discharge alone cannot treat. Also report oral pain or a cat that seems interested in eating but backs away from the bowl.
Complications and consequences
Without treatment, rhinitis may progress to:
- A chronic form with persistent nasal discharge.
- Sinusitis, inflammation of the sinuses.
- Bacterial complications.
- General weakness and weight loss as appetite declines.
Weight loss depends on how illness affects eating and general condition, rather than simply the amount of nasal discharge.
Diagnosis at the vet
Investigations include:
- History and clinical examination.
- Viral samples and PCR testing for herpesvirus and calicivirus.
- Bacterial culture of discharge.
- X-rays or CT for suspected sinusitis or a tumour.
- Nasal endoscopy when needed.
Tests depend on symptom duration, severity and findings. Not every test is needed in a mild acute case. Persistent, recurrent, bloody or one-sided signs increase the need to look beyond an ordinary upper respiratory infection. The practice also assesses the mouth, teeth, eyes, eating and hydration.
PCR looks for a pathogen's genetic material. A positive herpesvirus result may reflect low-level shedding rather than establish that it explains every symptom. Results are interpreted alongside sampling site and clinical findings. One negative result does not resolve every cause of persistent nasal signs either.
Bacterial culture of superficial nasal discharge may contain normal local bacteria. It does not automatically identify the cause of deeper inflammation. Targeted tissue samples or endoscopic samples are taken when needed. CT shows nasal cavity and sinus structures, whereas biopsy helps distinguish inflammation, fungal changes and a tumour. Even extensive investigation does not always confirm a precise cause.
Treatment
Treatment depends on the cause and your cat's condition. Symptomatic care may be enough for mild viral rhinitis. Antibiotics do not work against viruses and are not automatic treatment for clear discharge. If bacterial complications are suspected, the vet assesses medication and sampling needs.
Fungal infection, a foreign body or dental disease requires different care from ordinary viral infection. Herpes-related eye disease may need topical or other antiviral medication. Temporary improvement with antibiotics does not establish bacteria as the only cause. Recurrent signs prompt investigation rather than repeated courses alone.
A seriously ill or dehydrated cat may need hospital care and fluids. If eating fails, safe nutritional support is planned, sometimes through a feeding tube. Poor intake must not be left untreated because nasal signs look mild externally.
Home care and monitoring
Gently wipe discharge around the nose and eyes with a damp, soft cloth. Do not insert instruments into a nostril or try to remove a deeply visible foreign body. Use medicines and nasal products only according to veterinary instructions given for your cat.
Offer favourite food in a quiet place. Gentle warming may strengthen its smell, and wet food may appeal more to a congested cat. Do not force food into the mouth with a syringe if your cat struggles to breathe or refuses food. Report reduced eating and drinking to the practice. Record the amount actually eaten as well as food offered. Visiting the bowl does not guarantee adequate nutrition if your cat only sniffs or takes a few mouthfuls.
Record ease of breathing, discharge changes, appetite and activity. Report deterioration despite treatment or a rapid return of symptoms. In multi-cat homes, arrange contacts according to veterinary advice. Transmission may occur through direct contact and bowls or hands contaminated with secretions.
Prognosis
Acute signs may improve, but longstanding mucosal damage can cause recurrent episodes. Chronic rhinitis management may aim to reduce symptoms and maintain eating rather than achieve a complete cure. A new change in symptom pattern needs investigation even in a cat with existing chronic rhinitis.
Prevention
To reduce the risk of rhinitis:
- Vaccinate against viral diseases according to your vet's plan.
- Keep animals clean and avoid dust and smoke.
- Remove exposure to confirmed allergens.
- Treat cat flu and viral infections promptly.
Vaccination reduces harm from certain viral diseases, but does not prevent every infection or eliminate latent herpesvirus. Vaccinated cats can also develop nasal symptoms. Wash hands between handling cats and keep feeding equipment clean. Reduce smoke, dust and clearly associated irritants, but do not replace investigation of persistent symptoms with environmental changes alone.
What it means for owners
Catarrhal rhinitis is a common symptom that is not always harmless. If discharge and sneezing persist beyond two to three days, or apathy and fever develop, seek veterinary care. Early recognition and treatment prevent complications and chronic disease.
The two- to three-day period is not a waiting time for an unwell cat. Breathing difficulty requires immediate help; refusal to eat, severe tiredness or eye pain warrants earlier contact too. Treatment can reduce complications, but chronic disease cannot always be prevented even when the early episode was managed appropriately.
Frequently asked questions
Is clear nasal discharge always an allergy?
No. It can occur with viral infection and mucosal irritation too. Allergic rhinitis is possible but unusual in cats, so the overall symptoms guide assessment.
Does a cat with rhinitis need antibiotics?
Not in every case. Antibiotics do not treat viruses, and bacteria in nasal discharge may reflect normal flora. The need is assessed from general condition and investigations.
Can herpesvirus cause rhinitis again?
Yes. The virus can remain latent and reactivate. Recurrent rhinitis is nevertheless not automatically considered herpes-related if symptoms change or findings suggest another cause.
When does congestion need urgent help?
Open-mouth breathing, obvious respiratory effort, blue mucous membranes and collapse require immediate contact. Seek prompt advice for refusal to eat, weakness or a painful eye too.
This article is for general information only and is not a guide to treatment. If you notice the first signs of illness, contact your vet.
Paw4care editorial team
Sources
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- Rhinitis and Sinusitis in Dogs and Cats, Merck Veterinary Manual, accessed 2026-11-05.
- Guideline for Feline Herpesvirus Infection, ABCD, accessed 2026-11-05.
- Respiratory: Companion Animal Medical Guidelines, University of Melbourne, accessed 2026-11-05.
- Dyspnea (Difficulty Breathing), Cornell University College of Veterinary Medicine, accessed 2026-11-05.
- 2022 ISFM Consensus Guidelines on Management of the Inappetent Hospitalised Cat, Journal of Feline Medicine and Surgery, accessed 2026-11-05.
- 2024 guidelines for the vaccination of dogs and cats, WSAVA, accessed 2026-11-05.
- Herpesvirus Infection in Cats (Feline Viral Rhinotracheitis), VCA Animal Hospitals, accessed 2026-11-05.