Cat Runny Nose — Cold, Allergies or Infection?

A discharge from your cat's nose might be minor or a sign of something that needs attention—here's how to tell the difference and when to reach out to a vet.

Chat With a Vet 24/7

Quick Assessment: Is It an Emergency?

Many cases of mild nasal discharge are associated with viral upper respiratory infections and may improve with supportive care, but veterinary evaluation is recommended—especially for kittens, senior cats, or cats with reduced appetite or lethargy.

🚨 Call a vet now if you see:

  • Nasal discharge with blood or pus mixed in
  • Difficulty breathing or wheezing alongside nasal discharge
  • Lethargy, fever, or refusal to eat for more than 24 hours
  • Discharge from one nostril only (suggests polyp, tumor, or foreign object)
  • Swelling around the nose, face, or eyes
  • Discharge that worsens rapidly or lasts longer than 2 weeks

👀 Monitor at home if:

  • Clear or slightly cloudy discharge without blood or pus
  • Runny nose started recently and cat is otherwise eating and playful
  • Mild sneezing or nasal congestion but no fever or lethargy
  • Discharge appears during seasonal changes and improves with humidity
  • Cat is grooming normally and breathing sounds clear
  • Single episode without spreading to other cats in the household

Common Causes

1. Upper Respiratory Infection (URI)

Viral or bacterial infections of the nose, sinuses, and throat are common in cats and often follow stress, overcrowding, or exposure to other sick cats. The discharge is typically clear to milky, and affected cats may sneeze, cough, or run a low fever. Most viral URIs resolve within 7–10 days with supportive care, though secondary bacterial infections can prolong symptoms.

2. Feline Herpesvirus (FHV-1)

This viral infection is extremely common in cats and causes sneezing, nasal discharge, eye discharge, and sometimes ulcers in the mouth. The discharge may be clear initially, then become thick and colored as the infection progresses. Cats may develop latent infections that reactivate during stress, causing recurring bouts of nasal congestion.

3. Allergic Rhinitis

Cats can develop allergies to environmental triggers such as dust, pollen, mold, or household sprays, resulting in sneezing and nasal discharge. Allergic discharge is typically clear and watery and is often accompanied by itching around the nose and face. Symptoms may follow a seasonal pattern or occur year-round if the allergen is constant.

4. Nasal Polyps or Masses

Benign polyps or, less commonly, tumors can develop in a cat's nasal passages and cause discharge from one nostril, snoring, or difficulty breathing. These growths are more common in older cats and may require imaging or endoscopy to diagnose. If suspected, a vet should evaluate to rule out malignancy.

5. Feline Calicivirus

Another common respiratory virus that causes sneezing, nasal discharge, and sometimes mouth ulcers. Calicivirus discharge may be accompanied by fever, lethargy, and lack of appetite. Like herpesvirus, it can become chronic or reactivate in carriers, especially during times of stress.

6. Fungal Infection (Cryptococcosis)

Cryptococcal infection is rare but serious and occurs when a cat inhales fungal spores from the environment. Nasal discharge may be bloody or purulent, and the cat may develop facial swelling, neurological signs, or systemic illness. Diagnosis requires culture or special staining, and treatment is prolonged.

7. Foreign Body or Trauma

Occasionally, a grass blade, seed, or small object becomes lodged in the nasal passage, causing discharge, sneezing, and sometimes bleeding. Trauma to the nose from a fall or fight can also trigger temporary discharge. Most foreign bodies require removal by a vet under anesthesia.

8. Dental Disease

Severe infections of the upper teeth can erode into the nasal sinuses, creating a pathway for bacteria and causing purulent discharge, especially from one side of the nose. The cat may show signs of mouth pain, bad breath, or difficulty eating. Treatment typically involves dental extraction and antibiotic therapy.

Home Care & Monitoring Tips

Never give human medications without veterinary guidance. Monitor hydration and seek care if your cat stops drinking.

  • Increase humidity by running a humidifier or placing a warm, damp cloth near (not in) your cat's breathing space to ease congestion.
  • Offer wet food or broth-based meals to encourage eating and fluid intake if her sense of smell is reduced.
  • Wipe away discharge gently with a soft, damp cloth to keep her nose clean and reduce irritation.
  • Ensure your cat has access to fresh water at multiple locations and consider a cat water fountain to encourage drinking.
  • Keep her environment calm and stress-free, as stress can worsen viral reactivation and slow recovery.
  • Isolate her from other cats if you suspect a contagious virus to prevent spread.
  • Monitor her appetite, energy level, and breathing daily, and keep notes on when discharge appears or worsens.

When to See a Vet

Any nasal discharge lasting longer than 7–10 days should be evaluated by a veterinarian, particularly in kittens or older cats.

  • Nasal discharge lasts longer than 7–10 days despite home care
  • Discharge is bloody, purulent, or foul-smelling, or appears from only one nostril
  • Your cat shows fever, lethargy, refusal to eat, or difficulty breathing
  • Nasal discharge is accompanied by eye discharge, facial swelling, or mouth ulcers
  • Your cat is very young, very old, or immunocompromised (FIV or FeLV positive)
  • Discharge worsens despite a week of supportive care at home

Frequently Asked Questions

Is a runny nose in cats contagious to other cats?

Many causes of nasal discharge—particularly viral infections like herpesvirus and calicivirus—are highly contagious between cats. If you have multiple cats, isolate the affected cat from others while symptoms persist, practice good hand hygiene between handling cats, and ensure all cats are up to date on vaccinations. Even vaccinated cats can catch respiratory viruses, though vaccination typically reduces severity.

What color of nasal discharge should worry me?

Clear or slightly cloudy discharge is usually less concerning and often viral or allergic in nature. Thick, yellow, green, or bloody discharge suggests bacterial infection, fungal disease, or other serious conditions and warrants a vet visit. Any discharge with an unusual odor also signals infection.

Can I use saline nasal drops to help my cat's congestion?

Gentle saline rinses or drops made for cats can be safe and soothing, but most cats resist nose drops because they find it uncomfortable. A humidifier and warm compress are usually more practical and just as helpful. Always ask your vet before using any preparation, especially medicated sprays or drops.

Should I give my cat antibiotics for a runny nose?

Antibiotics are only helpful if the discharge is caused by a bacterial infection, not a viral one. Using antibiotics unnecessarily can promote resistance and upset your cat's microbiome. Your vet will determine whether antibiotics are appropriate based on the suspected cause and severity.

How long do respiratory infections last in cats?

Many uncomplicated viral upper respiratory infections improve within 7–10 days, but some cats may have lingering symptoms or recurrent episodes, especially with herpesvirus infections.

Can stress cause my cat's nasal discharge to come back?

Yes, stress is a major trigger for reactivation of latent herpesvirus infections in carrier cats, often causing a flare-up of sneezing and discharge. Environmental stressors like moving, introducing new pets, boarding, or changes to routine can precipitate symptoms. Minimizing stress through routine, pheromone diffusers, and a calm environment can help prevent recurrence.

When should I contact a vet right away versus waiting to schedule an appointment?

Cats that stop eating for more than 24 hours should be evaluated by a veterinarian, as prolonged anorexia can lead to serious metabolic disease.

Is there a vaccine to prevent feline upper respiratory infections?

Vaccines for herpesvirus and calicivirus are available and recommended for all cats, especially those in multi-cat households or shelters. However, vaccination does not guarantee immunity, and vaccinated cats can still catch these viruses, though disease is usually milder. Keeping your cat up to date on boosters provides the best protection.

Related Cat Health

My Cat Has Fleas — How to Get Rid of Them Fast

Cat Over-Grooming & Pulling Out Fur — Causes & Solutions

Why Is My Cat Hiding? When It's Normal & When It's a Problem

Cat Suddenly Aggressive? Causes & How to Help

Cat Meowing at Night — Why & How to Stop It

Cat Drooling — Is It Normal? Causes & Warning Signs

Medical disclaimer: This content is for general informational purposes only and is not a substitute for professional veterinary advice, diagnosis, or treatment. Always consult a licensed veterinarian about your cat's health, especially for any urgent symptoms or before starting a new treatment. Meow Mobile members get 24/7 access to licensed vets via chat and video.

Unsure If Your Cat's Runny Nose Needs Urgent Attention?

Talk to a licensed vet anytime, day or night, without leaving home or waiting for an appointment—available 24/7 with Meow Mobile.

Get Started