What is it and how do cats catch it?

Cat ‘flu is an infection of the upper respiratory tract that is like human colds and flu and is particularly dangerous for kittens, elderly cats or cats with a compromised immune system. 

Although most dangerous for the young and old, it is an unpleasant illness for any cat to suffer and can lead to dangerous secondary infections which can be life threatening. It makes the cat feel weak and ill with a sore throat, breathing difficulties and in some cases, mouth ulcers. The symptoms can put them off eating and drinking leading to a lack of strength to fight the infection, and dehydration. Any cat suffering will need to be carefully monitored and attentively nursed back to health as it is a dangerous illness that can cause serious secondary illnesses. 

Any cat or kitten suspected of having cat flu should be seen by a vet as soon as possible so their condition can be monitored and they can be treated and nursed carefully. The infection is easily spread when an infected cat sneezes, spreading nasal discharges, or through contact with their tears or saliva so quarantining any ill cat if you have several cats, is important. 

What causes cat ‘flu?

Most cat ‘flu is caused by one of two viruses. The feline herpes virus causes a more serious version of ‘flu resulting in clear nasal discharge that turns thick and pus-like as the infection progresses, coughing and sneezing, sore throat, runny eyes and conjunctivitis. The cat will be dull, depressed and lethargic, may go off their food and not drink enough, and develop a fever. This illness can clear up within 2-3 weeks with careful nursing and if they eat and drink enough. Some cats can be left with a permanent or intermittent runny nose due to damage of their nasal passages, or eye damage.

Very young kittens, older cats or those with a compromised immune system can sometimes develop secondary infections such as pneumonia or become dangerously ill through dehydration or lack of food. Good hydration and nutrition are crucial for recovery. 

The other virus that causes cat ‘flu is called the feline calicivirus and in most cases causes a less serious version of the illness. This ‘flu causes runny eyes and nose and tends to cause ulcers on the hard palate, tongue and nose, too. In kittens this virus can also create a temporary arthritis causing lameness. This version of cat ‘flu is often seen in cats with chronic gum disease, but it’s not really known why.

In recent years a more virulent version of feline calicivirus ‘flu has emerged which is much more serious and causes the cat to have a puffy face, paws, develop jaundice and haemorrhage as well as the usual respiratory symptoms, but thankfully it is relatively rare. 

There are 2 other organisms that cause much less serious versions of cat ‘flu: Bordetella bronchiseptica and Chlamydophila felis. The Bordetella bacteria also causes kennel cough in dogs.

How do you prevent it and what should you do if you think your cat has it?

The best form of prevention is vaccination. The cat ‘flu vaccine protects your cat from getting the illness or if they do get it their symptoms will be significantly reduced and they will recover more quickly. The vaccine consists of 2 doses initially and then an annual booster injection so it’s simple to protect your cats and stop them from experiencing this awful illness. The illness is easily spread and so if you have several cats you must vaccinate all of them. 

If you suspect one of your cats has cat ‘flu take them to the vets for a diagnosis and to discuss their care and treatment. The illness will be diagnosed through examination of your cat and their symptoms. Your vet may take a mouth swab to send off for examination at a lab to pinpoint the organism responsible for the illness.

If you have several cats make sure you isolate the ill cat from the others, wash and disinfect all feeding and water bowls, litter trays and common areas to minimise the risk of the illness spreading. 

How do you treat cat ‘flu? 

If you think you cat might have cat ‘flu take them to the vet to get a diagnosis and treatment plan. Having pet insurance can help you to cope financially with the treatment and nursing care your cat might need if it is unlucky enough to get cat ‘flu so it’s always a good idea to take out a policy when your kitten is young to ensure you are covered. You can look at cat insurance policy options on our compare cat insurance page and get quotes direct from our insurance partners. 

Following a visit to the vet any cat with ‘flu will need careful nursing and you will need to monitor their condition closely as the illness can be serious. Make sure you keep them warm and comfortable with easy access to water, food and the litter tray. Keep checking on them regularly, and you can help to keep their eyes and nose clear of discharges using some damp, warm cotton wool to gently bathe their nose and eyes. 

Breathing steam can help them to clear their nose and airways so put them in a cage or carry box and taking them into the steamy bathroom with you when you shower or have a hot bath. Put a bowl of steaming water next to their cage and drape a towel over their cage and the bowl so they breathe the steamy air.    

They may be reluctant to eat as they lose their sense of smell and have a sore throat, but it is important they have food to enable them to fight the infection. You can encourage them to eat by feeding them smelly food such as sardines or other fish and you may have to feed them by hand for a while. They also need to drink so if you are at all worried take them to the vet as they may need to be tube-fed or put on a drip until they improve.  

There are no drugs to kill the viruses (although there have been recent advances made using human herpes treatments but it is early days on this). However, your cat may need antibiotics to prevent secondary bacterial infections such as pneumonia or intensive nursing care in a vet hospital until they are over the worse of the illness.

Are there any long-term health implications, and should a cat that has already had ‘flu be vaccinated?

Some cats who suffer cat ‘flu can be left with damage in their nasal passages that can give them an intermittently runny nose, and some suffer eye damage. Some cats who have had the illness become carrier cats who show no symptoms but can spread the illness. 

It is important to vaccinate your cat against cat ’flu whether they have had the illness or not as it will protect them from the virus they didn’t get the first time!