TALK TO THE VET
by
FELINE LEUKEMIA VIRUS - The Other Virus Every Cat
Owner Should Know About
WHAT: Feline Leukemia Virus (FeLV) affects 2-3% of cats
nationwide. It is a disease that reduces the immune sys-
tem’s ability to protect itself against common bacterial,
fungal, viral or protozoal infections. FeLV occurs worldwide
and while all cats can get FeLV, outdoor and intact male
cats have a higher risk of infection since these cats have
an increased chance of contact with other cats and fluid
exchange through biting. FeLV only infects cats and cannot
be transmitted from your pet to you or your family.
HOW: Cats become infected with FeLV after bite wounds
from an infected cat or from prolonged contact with infect-
ed cat saliva, nasal or tear secretions. Grooming or shared
water/food bowls may also result in infection. The FeLV or-
ganism does not survive in the environment therefore feces,
urine, aerosol transmission is unlikely. Rarely the disease
can be passed across the placenta, via lactation or through
sexual contact. Although a cat can be exposed to the FeLV
organism, whether or not it actually becomes infected is
largely dependent on how much virus was introduced, the
age of the cat when exposed and, most importantly, the
strength of the cat’s immune response. Cats can clear the
virus after a self-limiting infection or they can sequester the
virus for years until it is activated later in life.
SIGNS: Ever the master at hiding disease, cats may hide
any sign that they are infected until the disease is well un-
der way. “My cat is just not feeling well,” may be the first
observation that prompts an owner to bring their cat to
the veterinarian. Signs of advanced infection may include:
Loss of appetite and weight loss, Weight loss, Weakness,
Pale gums, Mouth sores, Diarrhea, Enlarged lymph nodes,
Squinting, tearing or redness of the eyes
TESTS: A simple ELISA blood test that detects FeLV parti-
cles in the bloodstream is the standard initial screening test.
It usually takes about 1-2 weeks after becoming infected to
test positive on the
ELISA test. As infection progresses, the bone marrow can
become involved. Remember that although a cat may have
the virus in the bloodstream, there is a chance that he/
she can clear the disease from the body before it reach-
es the bone marrow. Therefore any cat who tests positive
on the ELISA blood test should be confirmed with an IFA
blood test, which checks for viral particles in white blood
cells. Cats with a positive ELISA result but a negative IFA
By Dr. Eve Flores DVM, CVA
result are probably not contagious at that time, but should
be isolated until they are re-tested in 4-6 weeks, because
they may be progressing to persistent infection. A definitive
diagnosis is made whe