Nasal Congestion in Cats: Causes, Safe Home Care, and When to See a Vet

Updated September 22, 2026. Fact-checked against veterinary sources; review by a licensed veterinarian is in progress. See our editorial policy.

Quick answer: Nasal congestion in cats is most often caused by an upper respiratory infection (a “cat cold”), usually from feline herpesvirus or calicivirus. Most mild cases improve within about 7–10 days with supportive care at home: a steamy bathroom several times a day, gently wiping the nose, and strong-smelling food to keep your cat eating. See a vet if your cat stops eating, breathes with an open mouth, has thick colored discharge, a nosebleed, discharge from only one nostril, or is a kitten, senior, or has other health problems. Never give a cat human cold or decongestant medicine; many are toxic to cats.

Common causes

Upper respiratory infections (URIs). Feline herpesvirus-1 and feline calicivirus cause roughly 90% of cat URIs. Bacteria such as Bordetella and Chlamydia felis can cause or complicate infections. Signs include sneezing, congestion, eye and nose discharge, and sometimes fever.
Recurring herpesvirus flare-ups. Cats that carry herpesvirus can have repeat episodes, often during stress.
Chronic rhinitis. Past infections can permanently damage the delicate structures inside the nose, leaving some cats with long-term congestion.
Nasal polyps, especially in young cats.
Something stuck in the nose, such as a blade of grass, often causing sudden sneezing and discharge from one side.
Dental disease, when an infected upper tooth root affects the nasal passage.
Fungal infection, most notably Cryptococcus, which can cause swelling over the bridge of the nose.
Tumors, more common in older cats, often with one-sided or bloody discharge.

Home care that actually helps

For a cat with a mild cold who is otherwise eating, drinking, and acting fairly normal, these vet-recommended steps can help:

Humidity. Bring your cat into a steamy bathroom for 10–15 minutes, several times a day, or run a cool-mist humidifier nearby. Never put a cat in the shower or near a steam source directly.
Keep the face clean. Gently wipe discharge from the nose and eyes with a soft cloth or tissue moistened with warm water.
Encourage eating. Congested cats can’t smell well, so they often lose their appetite. Offer strong-smelling canned food, warmed slightly to body temperature (stir and check it isn’t hot).
Keep them drinking. Fresh water, a pet fountain, or adding water to canned food helps.
Rest and low stress. A warm, quiet spot helps recovery, and stress can trigger herpesvirus flare-ups.
Separate sick cats from other cats and wash your hands after handling them, since URIs spread easily between cats. They’re not typically contagious to people or dogs.

Home remedies to avoid

Human decongestants and cold medicines. Products containing pseudoephedrine, phenylephrine, or acetaminophen (Tylenol) can be deadly to cats.
Essential oils and diffusers, including eucalyptus, tea tree, and peppermint. Cats are especially sensitive to essential oils, and inhaling or licking them can cause poisoning.
Vapor rubs like Vicks, which contain camphor and menthol.
Human nasal sprays, unless your vet specifically prescribes one. Your vet may recommend plain saline drops in some cases.
L-lysine as a cure-all. It’s widely sold for cats with herpesvirus, but current research does not show that it prevents or treats infection, so don’t rely on it in place of veterinary care.

When to see a vet

Go the same day, or to an emergency clinic, if your cat:

Breathes with its mouth open or seems to struggle to breathe
Hasn’t eaten in more than 24 hours. Cats that stop eating can develop a serious liver condition called hepatic lipidosis
Is very lethargic, hiding, or has a fever
Is a kitten, a senior, or has other conditions such as FIV, FeLV, diabetes, or kidney disease

Book an appointment soon if your cat has thick yellow or green discharge, eye ulcers or squinting, mouth ulcers, a nosebleed, discharge from only one nostril, facial swelling, or congestion lasting more than about 10 days or coming back often.

How vets treat it

Treatment depends on the cause. For URIs, care is mostly supportive. Antibiotics don’t kill viruses, but your vet may prescribe them if a bacterial infection is suspected, particularly in kittens. Antiviral medication such as famciclovir, eye medication, appetite stimulants, fluids, or nebulization may also be used. Chronic or one-sided congestion may need X-rays or CT, rhinoscopy (looking inside the nose with a camera), cultures, or a biopsy to find the cause.

Prevention

Keep your cat up to date on core vaccines, which cover herpesvirus and calicivirus. Vaccination doesn’t always prevent infection, but it makes illness less severe.
Reduce stress, especially for cats known to carry herpesvirus.
Quarantine new cats for a couple of weeks before introducing them.
Keep up with dental care.

Frequently asked questions

How long does a cat cold last?

Most uncomplicated cases improve within 7–10 days. If signs last longer, worsen, or keep coming back, see your vet.

Can I give my cat Benadryl for congestion?

Don’t give any human medication without your vet’s direction. Antihistamines generally don’t help cat colds much, and combination products may contain decongestants or acetaminophen that are toxic to cats.

Can my cat give its cold to me or my dog?

The common cat cold viruses are specific to cats. Bordetella can occasionally pass between cats and dogs, so good hygiene is still wise.

Sources

This article is for general education and is not a substitute for care from your own veterinarian. Learn about The Pet Vet and our editorial policy.