Feline leukemia virus (FeLV), like feline immunodeficiency virus (FIV), is a
slow-developing virus that weakens a cat’s immune system, much as AIDS affects
humans. It is a common cause of illness and death in pet cats, which can be
infected with both FeLV and FIV, the symptoms of which are usually less severe.
FeLV transmission among cats is spread through their saliva; cats usually
become infected through the nose and mouth. The virus can be spread in litter
boxes, and food and water bowls.
It is highly infectious, and readily spread by prolonged close contact,
biting, and grooming. Incidence is about 3% in single-cat households and up to
11% among stray cats. Incidence is much higher in urban versus rural
populations. A cat becomes permanently infected if the virus spreads to the
bone marrow, and its health will deteriorate over time. 80-90% of all infected
cats die within 3 ½ years of diagnosis. FeLV does not infect humans or other
animal species.
The Most Common Symptoms
Fever
Lethargy
Poor appetite
Weight loss
Anemia
Cancer
Secondary infections due to immunosuppression
A blood test can show if your cat has FeLV, but there are occasional false
positives and negatives, so a confirmatory test may be needed. There is no
known cure for infection. There are several vaccines available; cats that roam
or live with other cats should also be vaccinated against other infections.
However, you should be aware than no vaccine is 100% effective. Also cats that
roam outdoors and those in multi-cat households are more at risk.
Treatment is supportive, not curative. Prompt treatment of
other infections with antibiotics and the use of vitamins, and steroids may be
included.