Cat ‘flu’ is caused by a combination of viruses affecting the eyes, mouth, nasal passages, and throat in cats. None of the the viruses are actually influenza, so it is a badly named condition.

The main viruses involved are Feline Herpes Virus, and Feline Calici Virus.

Many kittens become infected with herpes in the first few days after they are born, picking up the infection from their mother. Once they become infected they will always harbour the infection (just a like a person harbours a cold sore virus).

Because of the wide prevalence of these viruses among the feline population, it is extremely important to vaccinate young kittens against them.

Once infected, cats and kittens display many of the classic symptoms of the flu, namely fever, sneezing, and loss of appetite. In addition, severe blisters of the mouth and painful inflamed eyes are common. There is then also a risk of secondary bacterial infection which could lead to pneumonia.

In summary, whilst most infected cats will recover within 7 days or so, severe cases can take much longer. Unlucky individuals could be left with permanent respiratory complications and damaged eyes.