An occasional sneeze in a cat means as little as it does in a person. Sneezing that goes on for days, especially with discharge from the eyes or nose, usually means an upper respiratory infection.

Cat flu

Most persistent sneezing in cats is caused by feline herpesvirus or calicivirus, together known as cat flu. Both spread easily between cats and are very common in kittens, in rescue cats and in multi cat households.

Typical signs are sneezing, watery or thick discharge from the nose and eyes, red sore eyes, reduced appetite, mild fever and lethargy.

The important point about herpesvirus is that the cat does not clear it. The virus stays dormant for life and re-emerges at times of stress: a house move, a new animal, boarding, illness. Owners often describe a cat that “gets a cold every time something changes”. That is what is happening.

Why appetite matters here

A blocked nose stops a cat smelling its food, and a cat that cannot smell will not eat. This is why cat flu so often turns into a cat that has stopped eating, which is a problem of its own.

Warming wet food to release its smell helps. So does gently wiping the nose clear with cotton wool moistened with warm water.

Other causes

Sneezing that is not flu: a grass seed or other foreign body up the nose, which usually causes sudden violent sneezing on one side only; dental disease where a tooth root communicates with the nasal cavity; fungal infection; nasal polyps; allergy; and in older cats, tumours.

One sided discharge, especially if it is bloody, points away from simple flu and needs examining.

What to do at home

Keep the eyes and nose clean. Offer warmed, strongly scented food. Run a humidifier, or sit with the cat in a bathroom after a hot shower. Keep the cat warm and away from cigarette smoke and aerosols. Isolate it from other cats where you can.

When to come in

If the discharge turns thick, yellow or green. If your cat stops eating. If the eyes are held shut or the cornea looks cloudy, which suggests a corneal ulcer and needs treating quickly. If breathing becomes laboured. If sneezing is one sided or bloody. Or if the cat is a kitten, elderly or already unwell.

Vaccination does not prevent cat flu entirely, but it reduces how severe it is. It is part of the core vaccine and is worth keeping current.