Cat Flu

picture of ginger cat lying in bed

Cat flu occurs in cats of all ages, but it's usually more severe (and more likely to be fatal) in cats with weak immune systems - e.g. kittens, old cats and cats with feline immunodeficiency virus and cat leukemia virus.

Cause, Signs And Treatment

1) Cause

The disease got its name because the outward signs are similar to those of human flu. However, it's not caused by the influenza virus; most cases are caused either by feline herpes virus type 1 (FHV-1) and feline calcivirus (FCV).

These viruses are transmitted through the air and through direct contact, so there are many ways a cat can pick them up. They're spread through sneezing, contact with discharge from the infected cat's nose and eyes, and via food, bowls and bedding. A human can also spread them via their clothing and skin.

Because the disease is so infectious, as soon as you suspect your cat has flu, you should separate him from any other cats in your house, and keep him indoors. Be very meticulous about washing your hands after before and after touching him.

2) Signs

The signs of FHV-1 and FCV are different:


  • Swollen, red eyes that may develop a pus-filled discharge. Ulcers may develop on the eyes
  • Excessive feline sneezing
  • Nasal discharge which starts off clear and runny, but then becomes thick and yellowy-green
  • Fever and loss of appetite
  • Cat dehydration
These signs usually last 1 - 2 weeks.


  • Ulceration of the mouth, tongue and lips
  • Drooling (due to the mouth ulcers)
  • Runny nose and eyes, but no eye ulcers
  • Fever and loss of appetite
  • Joint pain
  • Sometimes ulcers on the paws
  • Cat dehydration
These signs usually last for 7 - 10 days.

3) Treatment

A cat with flu or suspected flu should always be taken to the vet - the sooner, the better.

As cat flu is a viral disease, there's no treatment as such; it can't be treated with antibiotics. Your kitty needs to be kept hydrated and as comfortable as possible whilst his immune system deals with the disease. He should be kept in a warm, well-ventilated room, and have plenty of fresh water near him to drink.

The discharge needs to be cleaned from your cat's nose and eyes; your vet will show you how to do this.

It can be very hard to get a cat with flu to eat, because his blocked nose severely reduces his sense of smell. Stronger smelling foods such as sardines and pilchards can be tried. Heating the food slightly will help it to release more of a smell.

Some cats with flu won't drink for a few days. If your cat becomes dehydrated and refuses to drink, the vet may prescribe intravenous fluids.

The vet may also prescribe antibiotics to deal with secondary bacterial infections. For advice on health insurance for your cat, click here.

Persistent cat flu that won't clear up can sometimes be one of the feline leukemia symptoms. If your vet suspects this, they'll recommend your cat has a blood test for cat leukemia.

4) Prevention

You can get your cat vaccinated against FHV-1 and FCV. I'd strongly recommend this. Vaccination doesn't always prevent cat flu completely, but an immunized cat will develop a much less severe form of the disease, if he develops it at all.

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