Winter is nearly here and many of us will spend the next few months sniffling and snuffling our way through a variety of colds and flu. But what about our pets? There are a variety of reasons why dogs and cats can start to cough and sneeze. But one of the most common reasons why cats may present with cold-like symptoms, and not just in winter, is a condition known as ‘cat flu’. 

Is cat flu like human flu?

No. Flu in people is caused by a group of influenza viruses that are constantly changing and mutating. This is why many vulnerable people are advised to get a flu vaccination every year. 

Cat flu is also not the same as a cold. In humans, colds are caused by a number of different respiratory viruses, mainly rhinoviruses. These are not transmissible to cats. 

So, what does cause cat flu?

There are two main viruses implicated in cases of cat flu; feline herpesvirus, otherwise known as feline viral rhinotracheitis, and feline calicivirus. These account for around 80% of infections, with the other 20% caused by bacteria such as Chlamydophila felis and Bordetella bronchiseptica. Very often however, we see mixed infections.

As with herpes virus in humans, once a cat is infected with feline herpesvirus, it will lay dormant in the body and during times of stress, will reactivate and cause symptoms. More than 90% of the UK cat population are thought to have been exposed to feline herpesvirus and would test positive. 

What are the symptoms of cat flu?

The classic signs of cat flu are 

  • runny nose
  • sneezing
  • weepy eyes
  • conjunctivitis
  • lethargy
  • fever

Cats will usually be fairly subdued and may not be keen to eat or drink. In severe cases, they may develop nasty ulcers in their mouth, on their tongue and around their tonsils. They can also get eye ulcers, especially if they have feline herpesvirus. Because the viruses can impair the function of the protective lining of the airways, infected cats can also be prone to getting secondary bacterial infections such as pneumonia which can severely damage the lungs. 

How is cat flu spread?

As with most respiratory diseases, the cat flu viruses are spread through droplets of respiratory secretions such as saliva, nasal discharge or eye discharge. These can either be transmitted via aerosol spread such as coughing or sneezing, direct contact with an infected cat, or indirectly by being in contact with an object such as a bed or food bowl which has recently been used by an infected cat. Cat flu is highly contagious so it’s important to keep an infected cat inside and away from other cats. 

How is cat flu treated?

There is no specific treatment for cat flu. Like with other viral infections, it must be left to run its course, whilst providing any supportive and symptomatic care that may be needed. Because of the risk of secondary bacterial infections, antibiotics may be given by a vet. But it is important to understand that they will not be effective against the causative viruses themselves. 

Cats are what we call obligate nasal breathers, meaning they will only breathe through their mouth if they are desperate. When their nose is blocked by discharge, they can therefore find breathing difficult. It can also put them off their food as they rely heavily on their sense of smell. Because of all this, decongestant medications may be helpful, as well as warming their food and providing tempting treats such as chicken or fish. Keeping their environment quite humid too can help, such as having them in a steamy room like a bathroom. 

Like in people, fluids are vital. Mildly flavoured water such as the water used to boil a chicken breast (ensure no added salt) or the spring water from a can of tuna can encourage them to drink if they’re reluctant. There are also rehydration fluids that can be supplied by your vet and are even flavoured to taste like chicken soup! 

It’s important to remember never to give human medications to your cat, as some, especially those containing paracetamol and other painkillers, can be highly toxic. 

Can cat flu be prevented?

We cannot definitively prevent cat flu. But we can greatly lessen its severity by vaccinating kittens as soon as they are eligible, around 8 weeks of age. In the UK, there are currently vaccinations available against feline herpesvirus and feline calicivirus which aim to reduce clinical signs associated with the viruses and in the case of feline herpesvirus, reduce shedding. Initially, cats will receive two vaccinations, given 3-4 weeks apart, then will require an annual booster vaccination. The vaccinations are commonly given in combination with those for feline enteritis and leukaemia. 

So although cats with cat flu can look like they have a cold, they have neither true ‘influenza’, nor a cold like we think of it in ourselves. Cat flu is an entity in itself. But it can still make the sufferer feel miserable and require a bit of extra TLC. The majority of cats will recover without any lasting effects but it’s still worth getting them checked by a vet if you notice any symptoms.

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