Feline Immunodeficiency Virus &
Feline Leukemia Virus:
Welcome to The Animal Hospital of Lynchburg's Feline AIDS and Feline Leukemia web page !!! Here you will find information about the viruses and clinical signs of two of the most common diseases of our feline patients.
FELINE LEUKEMIA VIRUS (FeLV)
Feline Leukemia virus infection was at one time the most common fatal disease of cats. Because we can now protect cats with the Feline Leukemia Vaccine, we are seeing fewer cases of the disease. However, it still remains a major cause of death in cats. Once your cat contracts the Feline Leukemia virus, it is very unlikely that it will ever be eliminated from their body, and will inevitably be fatal.
"Leukemia" means a cancer of the white blood cells. This was the first disease associated with the Feline Leukemia Virus (FeLV) and thus, the source of its name. We often use the term "leukemia" rather loosely to include all of the diseases associated with the virus, even though most are not cancers of the blood. This virus causes many other fatal diseases in addition to leukemia.
Another clinical sign can be "Lymphosarcoma" or "Lymphoma", which is a cancer of many different organs, but it begins in lymphoid tissue such as a lymph node. Almost any tissue may then be affected; organs commonly involved include lymph nodes, intestinal tract, kidneys, liver, spinal cord, brain, bone marrow and blood. Clinical signs are related to the organ affected. In younger cats, the lymphoma commonly manifests itself as a mass within the thoracic cavity, called "mediastinal lymphoma", which leads to fluid surrounding the lungs and an inability to breathe.
The noncancerous diseases caused by Feline Leukemia can include a variety of somewhat unrelated diseases. Anemia from bone marrow suppression is common. Infection of the bone marrow can also suppress the cats immune system and make them susceptible to many diseases they would ordinarily be able to resist such as respiratory infections.
Transmission of the virus is primarily through cat fights. Large quantities of the FeLV virus are shed in the cats saliva, and puncture wounds associated with fighting result in injection of the virus in to other cats. Some virus is also shed through respiratory secretions, but to a lesser extent, so spread through sharing food and water bowls and grooming is possible. Transmission from mother to kittens before birth is also possible.
FELINE IMMUNODEFICIENCY VIRUS (FIV)
Feline AIDS is caused by the Feline Immunodeficiency Virus. In years past, FeLV was the dominant immunosuppressant virus in cats, but with the earlier advent of the Feline Leukemia Vaccine, many areas are seeing less FeLV, but more FIV. FIV is likened to the human AIDS virus which affects people because of the similarities in the two diseases. Fortunately, most viruses are species specific. This is the case with the human AIDS virus and the feline FIV virus...AIDS only affects humans and FIV only affects cats. Once your cat contracts the Feline AIDS virus, it is very unlikely that it will ever be eliminated from their body, and will inevitably be fatal. This time frame can be from months to several years.
Transmission of the virus is primarily through cat fights. As with FeLV, FIV virus is shed in salivary and other bodily secretions and puncture wounds such as bite wounds, introduce the virus in to the body of other cats. Spread through sharing food and water bowls and grooming has not been shown to be a significant route of transmission at this time. As with FeLV, transmission from mother to kittens before birth is also possible.
TESTING AND PREVENTION
Our hospital uses an ELISA test performed on a blood sample that detects the FeLV virus (antigen test) or antibodies to FIV virus (antibody test) within your cat. These tests can be done in our hospital, and are very sensitive and specific tests. Because of the nature of the testing, occasional false positives for FIV are possible, but are distinguishable through further testing.
Feline Leukemia and Feine AIDS can be prevented !!! Prevention of the viral infections is through 3 main objectives. First, cats that are indoors are much less likely to come in contact with other cats outdoors, especially ones that might be harboring the FeLV or FIV viruses. Keeping your cats indoors is by all accounts the safest way to go. Second, if your cats cannot be indoors (and even if they can) spaying and neutering will decrease their tendency to roam and will greatly reduce the likelihood of confrontation and "cat fights" which is the typical way the viruses are spread from cat to cat. Lastly, vaccinations are available against Feline Leukemia (no vaccine currently available for FIV) that are extremely effective as well as safe. The Feline Leukemia (FeLV) vaccine is a series of 2 inoculations about 3-4 weeks apart. The vaccination is "boostered" on an annual basis.
Our recommendation is that all cats, regardless of age or previous history, be tested before beginning the vaccination series. Vaccinating your cats against FeLV if they have already contracted the virus will not eliminate the infection, and will do nothing to further their immunity. There are, at this time, no commercially available vaccines or any tests that can distinguish between a positive FIV test from exposure to the virus versus a positive FIV test from vaccination if one was done while they were on the market, but there additional tests run at research facilities that can help to differentiate.