Feline leukemia, a life-threatening disease, is caused by a virus known as FeLV. Approximately 85 percent of infected cats die of the illness within 3 years of diagnosis, making it the second most common cause of feline death, superseded only by traumatic injury. Because feline leukemia suppresses the immune system, serious secondary infections may develop in cats infected with the virus. Fortunately, exposure to FeLV does not mean a cat will die or even get sick. A good percentage of cats have strong enough immune systems to enable them to resist the virus on their own. Over the last few decades, cases of feline leukemia have declined considerably due to the develop of a vaccine for the disease, even though the vaccine is not 100 percent effective.
Risk Factors for Feline Leukemia
Kittens are more at risk of contracting leukemia because resistance to the disease increases with age. Kittens can become infected in utero by their mothers or by nursing from an infected mother when newborn. Cats who live indoors and have no contact with other cats are at extremely low risk. Dwellings or shelters in which many cats reside put cats at higher risk of developing the illness, particularly if water bowls, food dishes and litter boxes are shared.
Transmission of Feline Leukemia
Feline leukemia is transmitted through the saliva, blood, or, less frequently, urine or feces of an infected cat. The virus cannot survive for long outside the cat's body, so contact with infected material must happen within a few hours. The most common ways for the illness to spread are through fighting or grooming. It is important to note that any cat, even a cat that is apparently healthy, can spread the virus. Feline leukemia only infects cats; humans and other species are at no risk of developing the disease.
Symptoms of Feline Leukemia
While some cats may never become symptomatic, feline leukemia may cause a wide variety of symptoms, including:
- Jaundice (pale gums and whites of eyes)
- Swollen lymph nodes
- Loss of appetite, weight loss, lusterless coat
- Progressive weakness
- Bladder or skin infections
- Upper respiratory infections, trouble breathing
Cats that contract feline leukemia may also develop reproductive problems, such as sterility.
Diagnosis of Feline Leukemia
A simple blood test, known as EliSA, is used to detect feline leukemia proteins. Highly sensitive, this blood test can identify cats in the early stages of infection. Cats that manage to successfully fight the virus on their own will later test negative for leukemia proteins. Another blood test, called the IFA, is administered later to detect the progress of the disease. Cats testing positive to the IFA are less likely to recover from the illness.
Treatment for Feline Leukemia
While there is no known cure for feline leukemia, there are measures that can be taken to prolong life and make cats with the disease more comfortable. More frequent veterinary visits are necessary for cats who are infected so that any secondary conditions can be diagnosed and treated promptly. All cats with feline leukemia should be kept indoors, neutered, and kept away from other cats to avoid spreading the disease.