Cat Flu: Symptoms, Care and When to See a Vet

If your cat has started sneezing, with streaming eyes and a general air of feeling sorry for itself, this is the most likely explanation. Cat flu is the common name for upper respiratory infection in cats, caused mainly by feline herpesvirus and calicivirus, often with bacteria arriving on top.

It looks like a cold. It is usually rather more consequential than one, for a reason that is worth understanding properly.

Symptoms

• Sneezing, often in fits
• Discharge from the nose and eyes, clear at first, later thick and yellow or green
• Conjunctivitis: red, swollen, weeping eyes, sometimes gummed shut
• Mouth and tongue ulcers, which are painful and typical of calicivirus
• Drooling
• Fever, lethargy, hiding
• Loss of appetite
• Occasionally limping, particularly in kittens with calicivirus

Why appetite is the thing to watch

Cats decide whether to eat largely by smell. A cat with a blocked nose frequently stops eating altogether, not because it feels unwell enough to refuse food but because the food no longer registers.

That matters because a cat which stops eating for a few days starts mobilising fat to the liver faster than the liver can process it, which causes hepatic lipidosis. So a straightforward respiratory infection acquires a second, more serious problem, and overweight cats are at the greatest risk.

This is why "it is only a cold" is the wrong frame for cats.

How it spreads

Through sneezing, direct contact, and shared bowls and bedding. It moves rapidly through households, shelters and any group of cats.

Herpesvirus also has a particular characteristic: cats that recover carry it for life and shed it again when stressed. A house move, a new animal, boarding or an illness can trigger a flare in a cat that has been well for years, and that cat can then infect others.

Home care

For a cat that is still eating and reasonably bright:

• Warm the food and offer something strongly scented, such as tinned fish in water, to get past a blocked nose
• Wipe discharge gently from the eyes and nose with clean damp cotton, a fresh piece per eye, several times a day
• Steam. Sitting with the cat in a bathroom after running a hot shower loosens congestion. Do not put a cat near boiling water or use vapour rubs
• Keep it warm and quiet, and separated from other cats
• Encourage fluids. Wet food adds moisture; fresh water in more than one place helps

See a vet if

• The cat stops eating for 24 hours. This is the threshold that matters most
• It is a kitten, an elderly cat, or one with an existing condition
• Breathing is laboured, fast, or open-mouthed, which is an emergency in cats
• Discharge is thick, coloured or blood-tinged
• The eyes are gummed shut, cloudy, or the cat is squinting in obvious pain
• There are mouth ulcers, or drooling that stops it eating
• It is lethargic, hiding, or dehydrated
• It is not improving after a few days, or is getting worse

Eye involvement deserves particular attention. Herpesvirus can cause corneal ulcers, which progress quickly and can threaten the eye itself.

Treatment

Antibiotics do nothing against the viruses themselves and are used where secondary bacterial infection is present, which is common. Beyond that: pain relief for mouth ulcers, eye treatment where the cornea is involved, fluids for dehydration, appetite stimulants, and in serious cases hospitalisation and assisted feeding.

Never give human decongestants or cold remedies to a cat. Several are severely toxic, and cats are far less able than dogs to process common human drugs.

Protecting other cats

• Isolate the affected cat
• Separate bowls, bedding and ideally litter trays
• Wash hands between cats and change clothing if you have been handling a sick one
• Wash bedding hot and disinfect bowls

Calicivirus in particular survives well in the environment, so cleaning matters more than people expect.

Vaccination

The core FVRCP vaccine covers both herpesvirus and calicivirus. It does not guarantee a cat never gets flu, partly because multiple calicivirus strains circulate, but it substantially reduces severity, and severity is what determines whether a cat keeps eating.

For a carrier cat that flares under stress, reducing stress matters as much as medication: predictable routine, safe spaces, and preparation before known disruptions.

Cat flu is where a small delay compounds unusually fast. An owner reasonably decides that sneezing does not warrant a trip across town, the cat stops eating on day two because it cannot smell anything, and by day four there are two problems instead of one.

Every Skeepy Pet HMO plan includes unlimited vet consultations and covers illness treatment within the plan's limits, at any vet clinic in Nigeria, which makes going while it is still only sneezing the straightforward choice.