Feline leukemia virus is a contagious retrovirus that causes immunodeficiency, anemia and cancerous diseases in domestic cats. Unfortunately, infection by FeLV cannot be cured under current medical protocols. The goals of therapy are to manage the symptoms caused by secondary opportunistic infections and to control hematologic (blood), neoplastic (cancerous) and other conditions associated with the immunosuppressive effects of this disease.
Many FeLV-positive cats can live long, full lives if they are otherwise healthy. Once an infected cat becomes ill, however, the treatment options are rather limited. Secondary opportunistic bacterial infections are common and should be treated aggressively with appropriate antibiotics, to allow the cats’ immune systems to mount as strong a response to the associated FeLV infection as possible. Vitamin and mineral supplements may be recommended. Anemia (low levels of circulating red blood cells) may be managed with blood transfusions and close monitoring of red blood cell levels. Chemotherapeutic drugs may be helpful to treat FeLV-associated lymphoma, leukemia or other cancers, with varying degrees of success. However, FeLV-associated cancers are not curable, and most cats diagnosed with these cancers have an average survival time of less than 12 months.
Some anti-viral medications have been used to address FeLV infection in cats and appear to be most effective when given within a very short time (3 to 4 days) of exposure to the virus. While these drugs may reduce the symptoms of the disease for some period of time, they will not clear the virus from the cat’s body and can have significant adverse side effects. Sometimes, immunosuppressive doses of steroids, such as prednisone, can be helpful in increasing the levels of circulating white blood cells to boost the cat’s immune response to infection.
Cats that are FeLV-positive but otherwise healthy may live for years after diagnosis, with an excellent quality of life. They will need attentive supportive care, including high-quality nutrition, effective parasite control, a strictly indoor living environment and minimal stress. Unfortunately, cats that develop cancer, blood abnormalities, secondary infections or other diseases associated with FeLV have a guarded to poor prognosis, and they most often do not respond well to chemotherapy or other forms of medical management.