Feline Calicivirus (FCV) causes respiratory infections in cats. It is closely related to feline rhinotracheitis. Infection by both viruses is quite common. Feline calicivirus is responsible for 80 to 90% of all feline respiratory infections.
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A more virulent form known as 'virulent systemic feline calicivirus' has a mortality rate of around 67%. Those most likely to succumb to the disease are unvaccinated cats, old cats, kittens and those whose immune system is already weakened by illness. The disease is highly contagious.

The nose, mouth, throat and eyes are affected. Sometimes the lungs and intestines are also affected. The cat may become lame.


The incubation period for this disease varies from a couple of days to several weeks after exposure to the virus. Cold-like symptoms appear including fever, frequent sneezing, nasal discharge, watery eyes, heavy drooling and ulceration of the tongue. There may be conjunctivitis, fever and lethargy. The appetite will be suppressed. The watery secretions from the eyes and nose may become more mucous-like and sticky.

Lameness may also be present. Severe cases may contract pneumonia and exhibit anorexia and dehydration. Because of the weakened state of an animal with this condition, secondary infections may occur.


Transmission can be by direct or indirect contact. Direct contact occurs when the infection is passed on by cats coming into contact with saliva or with the discharge from the nose and eyes. Indirect contact occurs through contaminated surfaces such as food bowls or bedding. A cat can recover from this disease but then become a carrier, shedding the virus in excretions and more than likely infecting others.


Diagnosis is usually based on clinical signs. The presence of mouth ulcers will suggest calicivirus whereas coughing and corneal ulcers are symptoms of rhinotracheitis.

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Treatment is supportive. Antibiotics will not affect the virus but may be prescribed for secondary infections. If the cat is dehydrated, fluids may be prescribed. In extreme cases, force feeding may be necessary. It may be many weeks before infected cats regain their vitality and their condition.


The virus is tough and hardy, not easily killed. A solution of 1:32 dilution of household bleach is necessary for disinfecting purposes. Vaccinations may be given nasally or by injection. A 3-in-1 vaccination is available with panleukopenia and FVR vaccines. Three shots are given at three weekly intervals with booster shots administered annually. Your vet will advise on the best type of vaccine. Some cats develop the 'limping syndrome' after vaccination.

This disease is more common in areas of communal housing such as catteries and shelters. Overcrowding and stress-induced situations should be avoided.

Calicivirus affects all breeds of cat and occur globally. The incidence of the disease has been reduced by vaccination but the disease is spreading. Cats should be vaccinated against the disease. Feline calicivirus cannot be transmitted to humans.

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