What is Cat Flu

‘Cat flu’ is a common disease in unvaccinated cats of all ages, but tends to be particularly severe in young and especially purebred cats. A number of infectious agents have been found to cause ‘cat flu’ but the vast majority of cases will be caused by one of two viruses, feline herpes virus type 1 (FHV-1) and feline calicivirus (FCV). FHV-1 is also known as feline rhinotracheitis virus.

What are the clinical signs of ‘cat flu’ ?

Signs of ‘cat flu’ are similar to colds and flu in people. The major signs are inflammation of the lining around the eye (conjunctivitis) and nose (rhinitis). Mouth ulceration can be a prominent feature of the disease causing severe lack of appetite. Ulcers may also sometimes occur on the tongue, nose and hard palate This causes a clear discharge from the nose and eyes which becomes thickened and purulent as the disease progresses due to secondary bacterial infection. Cats tend to be dull and depressed with a raised temperature, sneezing and are reluctant to eat. Coughing is also a feature in some cases. Rarely the virus will cause skin lesions and invade the lungs causing pneumonia. It is important to seek Veterinary treatment as soon as possible to avoid serious disease

How is ‘cat flu’ diagnosed ?

In most cases the diagnosis is made on clinical signs but in cases where there is recurrent disease or in vaccinated cats a specific diagnosis may be required. This can be achieved by swabbing the cat’s mouth and sending the swab to a laborator.

What treatments are available ?

As for colds and flu, specific anti-viral treatments are not generally available. Treatment is aimed at controlling secondary bacterial infection (with antibiotics) and stimulating eating and drinking as, particularly dehydration, is a major cause of worsening disease. Anti-viral ointment used to treat herpes virus infections in people (cold sores) has been used in cats.

What can be done to help treatment?

Your cat can be encouraged to eat and drink using drugs such as multivitamins and mucolytics (which help dissolve secretions) but good nursing plays a crucial role. The eyes and nose can be kept clear of secretions by gently bathing the area with cotton wool and by steaming. Steaming needs to be undertaken carefully, the cat is placed in a wire basket and a bowl of steaming water is placed outside the basket, the two are then covered by a towel and the cat left for up to 5 minutes. The steam acts to loosen secretions making the cat feel better, oils such as eucalyptus should be avoided as they can cause ulceration of the nose in cats. Your cat can be encouraged to eating by providing highly flavoured foods e.g. sardines warmed to body temperature. Hand feeding can also help.
Severely ill cats may need nursing in hospital, this allows rehydration with intravenous fluids and sometimes feeding by naso-oesophageal tube.

How can ‘cat flu’ be prevented and controlled?

For most households, with a few cats, vaccination is sufficient. Vaccination may not prevent your cat becoming infected but will drastically reduce the severity of the disease, often to the point that all that is noticed is mild transient lethargy and inappetance for a few days. A variety of vaccines are available depending on the circumstances.
In multi-cat households, particularly where new cats are continually arriving (rescue, boarding or breeding), vaccination alone may not be sufficient to control the problem. In these households isolation and quarantine is also required. Disinfection, whilst an important part of disease control generally, is of limited value in respiratory virus control as most cats become infected by aerosol droplets sneezed or coughed out by infected cats. Clinically ill cats or those suspected of being carriers should be isolated and handled last, their food bowls and litter trays disinfected and your hands, face and boots washed before handling other cats. Where possible separate clothing or overalls should be worn. New arrivals to the group should be quarantined for 7-10 days in case they are incubating ‘cat flu’. Unfortunately, quarantine will not identify carrier cats. In households where ‘cat flu’ is endemic, queens should be kittened in isolation from other cats and, where possible, the kittens remain in isolation until vaccinated.

​What are carrier cats?

Carriers are animals that are infected with ‘cat flu’ but are not showing any clinical signs. Carriers are only infectious to other animals when shedding the virus. Viral shedding can be continual or intermittent. Carriers are animals that are infected with ‘cat flu’ but are not showing any clinical signs. Carriers are only infectious to other animals when shedding the virus. Viral shedding can be continual or intermittent. 

What should I do if my cat is a carrier ?

Nothing can be done to change the carrier status of your cat. Therefore it is important that your cat does not come into contact with unvaccinated cats or kittens. 

My cat has had ‘cat flu’ should I bother to vaccinate it ?

​YES! Your cat is likely to have been infected with only one of the viruses so will still be susceptible to infection with the other, or with other strains of calicivirus.