Cat Flu - Symptoms, treatment and causes

What is Cat Flu?

Cat flu is the general name given to a viral infection of the upper respiratory tract in cats. It is a common disease in cats and although not usually fatal in previously healthy adult cats it can be fatal in kittens and immuno-suppressed older cats.

Cat flu is most commonly caused by the Feline Herpes Virus-1 (FHV-1), or Feline Calicivirus (FCV)

Feline Herpes Virus is the more serious of the two. It is also known as Feline Virus Rhinotracheitis which is an older term for the virus.

Feline Herpes virus infects the membranes of the eyes, the lining of the nose, pharynx, sinuses, and throat.

Cat Flu: The most common symptoms of a Feline Herpes Virus (FHV-1) infection are:

The Eyes: The virus affects the membranes of the eyes. (Conjunctivitis) The eyes are swollen and red with a discharge that turns purulent (Purulent means 'filled with pus') as secondary bacterial infection invades. Sometimes the cat develop corneal ulcers.

The Nose: The nasal linings are inflamed (Rhinitis) and sneezing is usual. There is a discharge from the nose which begins as a clear fluid which can turn thick and green as the disease progresses. Cats often lose their sense of smell.

Fever and Depression & Loss of Appetite: Often the cat runs a fever and generally feels unwell. Cats will often lose their appetite and sometimes become dehydrated. Although they are dehydrated they may refuse to drink water.

Pregnancy: Often a pregnant cat will abort the kittens if infected with Feline Herpes Virus. If the kittens are born it is almost certain that they will catch the infection from the mother.

Cat Flu: What are the signs? The most common symptoms of Feline Calicivirus (FCV)

The Mouth and Tongue: The most common symptom of Feline Calicivirus is ulceration of the mouth and tongue, palate, lips and sometimes the tip of the nose. The gums can also be affected by gingivitis. Drooling can occur depending on the severity of the mouth ulcers.

The Nose and Eyes: The calicivirus causes cold like symptoms which result in runny nose and eyes. The infection can affect the membranes of the eye but does not cause eye ulcers.

Fever and Depression: The cat may or may not have a fever. Loss of appetite may occur but it is more common that the cat finds it too painful to eat because of the mouth ulcers. The infection becomes more serious when secondary bacterial infections like pneumonia invade.

The Joints: Joint pain can occur and you may notice your cat limping. FCV has been reported to cause a limping syndrome. The limping can affect first one leg and then another.

The Paws: There are several strains of the calicivirus and one of those strains causes ulcers in the paws.

Treatment of Cat Flu

Owners of cats with flu should always seek veterinary advice. There is no cure for a viral infection however the cat can be kept as comfortable as possible by keeping it warm and treating the symptoms. Your vet may prescribe eye drops or ointment for the conjunctivitis,
Corneal ulcers must be examined by your vet who will recommend appropriate treatment.
Discharging eyes and nose should be bathed frequently with warm salty water.
Secondary bacterial infection can be treated by your vet with antibiotics.
Mouth ulcers can be severe and cause your cat to stop eating. Your vet needs to be consulted if your cat has stopped eating and drinking. Sometimes the cat has to be hospitalized and force fed because the mouth ulcers are so painful it refuses to eat.
Dehydrated cats may need to be put on intravenous fluids (a drip) and this will require spending a day or two in hospital.
If the cat has lost it's sense of smell it will lose interest in it's food. Encourage your cat to eat by offering it strongly smelling food such as sardines.

How is Feline Herpes Virus and Feline Calicivirus spread?

Infected cats should be kept isolated from other cats
The virus spreads from cat to cat contact and with contact from the discharge from the nose and eyes. It can also spread from the cat sneezing much the same way a cold is spread in humans.
The virus can live outside the cat's body for a period of time and so infection can be transmitted via bowls, bedding, cages or in fact anything your cat comes into contact with. You can also spread the virus yourself from one cat to another on your hands or on your clothing.
The Herpes Virus can live outside the cat's body for approximately 24 hours but the Calicivirus can survive much longer sometimes for up to 7 - 10 days
Household bleach mixed at a ratio of 1:32 is a inexpensive and effective way of destroying the virus on washable items.