Why Your Cat Keeps Sneezing
Why cats keep sneezing: the cat flu viruses behind most cases and why they flare under stress, allergies, polyps, fungal infection, nasal vaccines, and when to see a vet, from the Merck Veterinary Manual. A reading guide, not veterinary advice.
AI illustration This is a reading guide to what veterinary references say about sneezing in cats. A cat that stops eating, breathes with effort, or has thick or bloody discharge needs a vet, and kittens and older cats should be seen early.
The short answer: in cats, the usual cause is a virus. The Merck Veterinary Manual calls viral infection the most common cause of sudden inflammation of the nose and sinuses in cats. Two viruses cause most of it: feline herpesvirus type 1 (feline viral rhinotracheitis) and feline calicivirus. Allergies, irritants, polyps and fungal infection are the other causes vets look for.
Cat Flu: The Two Viruses
Merck groups these infections as feline respiratory disease complex. Most upper respiratory infections in cats are caused by feline herpesvirus. Both viruses can infect a cat at once and are hard to tell apart.
| Feline herpesvirus (FHV-1) | Feline calicivirus (FCV) | |
|---|---|---|
| Mainly affects | Eyes and nose | Mouth and lungs |
| Typical signs | Fever, frequent sneezing, conjunctivitis, runny nose, drooling; discharge that starts clear and turns to mucus and pus | Mouth sores in some strains, pneumonia in others; some strains cause few or no signs |
| After recovery | The virus usually stays dormant in the body for life and can flare up again, especially under stress | Two strains can cause a brief “limping syndrome” in 8- to 12-week-old kittens |
The viruses spread in droplets from sneezes and on objects, including the hands of people who handle cats. Merck notes that recovering cats can shed the virus for many months. Signs last 5 to 10 days in milder cases and up to 6 weeks in severe ones. The outlook is generally good, except for young kittens and older cats (Merck).
Crowding and stress. Merck names exposure to sick cats, overcrowding and stress as the conditions to control, which is worth remembering before boarding or bringing a new cat home. For a cat that carries herpesvirus, stress can also set off a flare.
Other Causes
- Allergy: seasonal with pollen, or all year with house dust and molds.
- Long-term rhinitis after a bad viral infection. In cats, Merck says, chronic inflammation of the nose and sinuses often follows a severe viral infection. It is hard to manage, and cures are rare.
- Fungal infection, most often Cryptococcus. A lump on the bridge of the nose can be a sign.
- Nasopharyngeal polyps: benign growths, usually from the middle ear, that cause noisy breathing, sneezing and nasal discharge. They are removed surgically if they block the airway (Merck).
- A recent nasal vaccine. Cats given the vaccine as nose drops may sneeze often for a few days afterwards.
Care and Prevention
Treatment mostly eases the signs. Vets add antibiotics only for a bacterial infection on top of the virus. Wiping away nose and eye discharge often keeps the cat comfortable. Your vet may also suggest saline drops or a mist to loosen dried secretions. Loss of appetite is common as the illness goes on, and Merck notes that cats unwilling to eat may need extra medicine or a feeding tube. Vaccines against both viruses exist. Merck adds that vaccination, plus limiting crowding, stress and contact with sick cats, gives good protection. Our cat vaccines guide covers the schedule.
When to See the Vet
- Sneezing with fever, thick discharge with mucus or pus, a bloody discharge, or sore eyes.
- A cat that stops eating or drinking, or breathes with an open mouth or with effort.
- Any sneezing kitten or elderly cat.
- Sneezing that keeps coming back.
For dogs, see why your dog keeps sneezing.
