The Feline Leukemia Virus exists in all felines,
wild and domestic, in all parts of the world. It is spread from
parents to kittens and from cat to cat via biting, scratching, breeding,
sharing litter boxes and perhaps is vectored by biting insects like
fleas and mosquitoes.
There is a vaccine for Feline Leukemia, which is appropriate for
cats that go out or are exposed to outside cats. The vaccine is
given twice initially at a two to four weeks interval and then yearly.
The shots are optional for indoor, isolated cats. Even cats vaccinated
against the Feline Leukemia virus should not cohabitate with Feline
Leukemia positive cats as eventually the vaccine becomes overwhelmed
by the constant exposure to viral particles in the environment.
All cats should be tested for Feline Leukemia and the F.I.V. virus,
which is Feline Aids before they commingle to avoid contagion.
Research indicates that 60 to 80% of the cats that become infected
by the Feline Leukemia virus will develop a Feline Leukemia related
disease within two years. Twenty to forty percent of the cats can
live with the virus for prolonged periods without sickening. These
cats serve as a reservoir of the virus and can infect negative cats.
The Feline Leukemia Virus commonly causes the following diseases:
1. Bone Marrow Suppression Anemia
Symptoms: Malaise, paleness, weakness and inappetance.
2. Lymphosarcoma (Lymphatic Cancer)
Symptoms: Those above plus enlarged Lymph nodes, skin masses, vomiting
and/or diarrhea and increased respirations.
3. Feline Infections Peritonitis
Symptoms: Swollen abdomen, fever, inappetance, progressive lethargy
and increased respirations.
Symptoms: Same as number one.
5. Assorted Immune Suppression Related Diseases
Like Toxoplasmosis, Hemobartinella, persistent infections, and
Because of the multiplicity of symptoms of these diseases, Feline
Leukemia positive cats should be rechecked every three to six months.
Many of the signs are subtle and can only be picked up in a physical
examine or via blood tests.
A very small percentage of cats can test positive and later negative
for Feline Leukemia. We don’t understand how these cats throw
off the virus. There are various tests we use. The most common test
is very sensitive and can give false positive results. So we sometimes
use a different test to confirm or rule out the virus. There is
also a one to three month latent period after exposure when a cat
can test negative, especially if there was a chance of exposure,
so sometimes it is prudent to retest a Negative cat three months
So that you are not frightened we should point out that the cats
we test are approximately 97% Negative, but remember any new cat
coming into your home should be tested at least once for FELK and
the Feline Aids Virus. Contrary to popular belief there is no human
health risk from the Feline Leukemia Virus.