Animal Medical Care Feline Leukemia Virus

Feline Leukemia virus is a highly contagious and devastating retrovirus that is one of the largest causes of morbidity and mortality in the general cat population. The most common route of transmission is through saliva, which contains the highest concentration of the virus. Biting, grooming and licking can result in infection, but the disease can also be transmitted to kittens during nursing.

Clinical signs

Because of the nature of the disease, clinical signs vary widely depending on the type of infection and organ systems that are involved. Signs can include but are not limited to difficulty breathing, lethargy, anorexia, fever, oral ulcers and non-healing abscesses. Physical exam findings may include pale mucous membranes due to anemia, palpable intra-abdominal masses and enlarged organs. The disease can spread to the bone marrow and even potentially cause a type of cancer called lymphoma.

Testing for the virus

Whenever a new cat or kitten is introduced into a home, it is recommended to test them for the virus. This is commonly done during the first visit to the veterinarian, around 6-8 weeks of age. Even if the new cat will reside primarily indoors and exposure to infected cats will be minimal, initial testing is recommended because of the severity of the disease and high rate of contagion. The in-house test is a rapid screening diagnostic tool which only requires a few drops of the patient's blood.

Elimination and treatment

The virus itself is extremely unstable outside of the body and will die within a few hours of being on a dry surface. Household disinfection can be easily accomplished in a contaminated home. New cats that are introduced to a household should be tested to prevent exposure and spread of the disease. Vaccination against the virus is recommended in all cats who are outside and exposed to potentially infected free-roaming feral cats.

Unfortunately in an infected cat where the virus has spread to the bone marrow and lymphoid tissue, prognosis is poor. Treatment largely consists of supportive measures. Approximately 85% of infected cats will die within three years of diagnosis.

Vaccine protocol

Vaccinating cats that roam outdoors and have the potential for exposure and infection is highly recommended. The vaccine that we use is a non-adjuvanted recombinant vaccine that is given intradermally instead of subcutaneously. This allows a smaller volume to be given, and has immunologic benefits for better protection of your cat against the disease. Booster vaccinations are recommended annually.

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