Feline Leukemia Virus is considered to be the most prevalent cause of illness and death in domesticated animals. Feline Leukemia Virus, also known as Feleuk, is a common infection in cats that can have devastating effects to the wellbeing of any feline pet. This virus can create malignancy and is thought to cause one third of all cancer deaths in cats. Feline Leukemia infection can be catastrophic due to its ability to wreak havoc with the cat’s immune system and produce a very wide variety of disease presentations.
The Feline Leukemia Virus can affect any age of cat. Young, non castrated male cats are the most commonly affected. It is estimated that up to 25% of all sick cats are infected with the virus. It is also thought that approximately 2% of all cats are infected with the virus in urban regions. The infection is much less common in rural settings.
Cats become infected with Feline Leukemia from having a deep bite from an already infected cat. Once a cat has been bitten, there are three possible outcomes. The first is in a healthy body, the immune system can clear the infection. The second possible result is the virus gains access to the bone marrow and begins to replicate. At this stage, the cat is still healthy but the virus is beginning to destroy the immune system along with other problems. Also, during this time, the cat may be spreading the virus by biting other cats. These cats will die within 3 years due to Feline Leukemia related diseases. The final potential outcome is that the infection will become latent, causing problems to the cat when he or she is stressed or sick for other reasons.
The Feline Leukemia Virus rapidly divides in the bone marrow. By doing so, it is spread throughout the body. The bone marrow is taken over by the virus, and therefore, does not allow normal white blood cells to be produced. This can result in a compromised immune system and Leukemia. In the early stages of the disease, there are no clinical signs. These infected cats appear perfectly normal at first. Eventually, the infection will begin to cause general malaise, anemia, weight loss, enlarged lymph nodes, diarrhea, and tumor development. Because the infection attacks the bone marrow and the immune system, many cats suffer from secondary infections.
Your veterinarian may begin to consider Feline Leukemia after the cat has been seen more than usual for a variety of reasons. The diagnosis of Feline Leukemia is done in our hospital by a blood test. The blood is tested in the clinic and takes only a short time. If a test is positive, we know the cat is infected. However, due to the complex nature of the infection, not all cats that are infected will have a positive result. Therefore, if suspicion for Feleuk is high and the test is negative, your veterinarian may request a second test at a later date.
There is no treatment available at this time for Feline Leukemia Virus. If your cat is tested positive, your veterinarian can treat the secondary infections but is unable to cure the viral infection from your cat’s bone marrow. Treatment of the secondary infections will depend on what the specific problems are. Approximately 85% of cats diagnosed with Feline Leukemia will die within 3 years.
Feline Leukemia Virus can have devastating effects on a cat’s life and our relationship with our cats. The good news is that there is an effective vaccine available. At Twin Valley VHS, we recommend that all cats over the age of six months that have not been previously vaccinated for the infection should be tested. If your cat is found to be negative at that time, vaccinating should be started on all cats that have access to the outdoors or live with cats that go outside. Initial vaccine can start as early as 12 weeks of age. The vaccine requires a booster in 3 to 4 weeks and then is an annual vaccine. All strays or cats adopted from a shelter should be tested before introducing them to the household.
If you have any questions regarding the above information or any questions/concerns in general, please contact Twin Valley VHS at 745-6642.
Dr. Justin Noble DVM