Feline Leukemia Virus

Feline Leukemia Virus (FeLV) is a very important contagious disease of cats. It is responsible for causing more illness and death in cats than any other single disease.

Cats or kittens that are most susceptible to FeLV are those less than 4 months of age or who are suffering from immune suppression. Cats that spend time outdoors are at greater risk due to the prevalence of the virus in the “stray” cat population. Heredity, amount of exposure to the virus, and the particular strain of the virus also play a role in how the cat will be affected.

The virus is present in the saliva, tears and urine of infected cats. This allows transmission of the virus from cat to cat by grooming, fighting or shared food/water bowls and litter boxes. Female cats can also transmit the disease to their kittens while still in the uterus or the virus can be passed in the milk.

Not all cats that are exposed to the virus will get the disease. In general, 30% of the cats with prolonged exposure to the virus will actually get the disease and subsequently die. Survival time once a cat is diagnosed is quite variable. Survival depends on the cat’s age, condition and any other medical problems.

The signs of a cat with FeLV can be very vague. They may suffer an unexplained weight loss, inappetence, seem depressed or have other recurrent illnesses. The virus can cause cats to become anemic, suffer immune suppression, develop cancer or many other abnormalities.

Cat owners should be aware that there is a vaccine to protect against the virus. While no vaccine is 100%, this vaccine has been shown to be effective in the prevention of feline leukemia. We strongly recommend vaccinating cats that spend time outdoors or have a housemate that spends time outdoors. Any new cat brought into the household should be tested for FeLV prior to being taken home. Keeping your cats indoors, away from other cats, is the best defense against this fatal disease.

If you have any further questions or concerns about Feline Leukemia Virus please do not hesitate to call our office.