Introduction
The Feline Immunodeficiency Virus, also known as
FIV, was discovered in California in 1986. It is transmitted from cat
to cat primarily by bites, as the virus is shed in the saliva.
Intimate contact through grooming, sharing food etc. does not spread
the virus.This disease is found worldwide. FIV is closely associated
with FeLV-
you should learn about both diseases if you have a cat.
FIV preferentially infects white blood cells which
are an essential part of a cat's immune system. The virus disables or
destroys the white blood cells, and leaves its host susceptible to
infections. Once a cat is infected with FIV it is infected for life
and can transmit the virus if it bites another cat.
Even though this virus acts similar to the AIDS virus
in people, humans are not infected with FIV.
Cause
FIV is caused by a retrovirus called the lentivirus. It is
similar to the retrovirus that causes FeLV in cats, and causes similar symptoms,
particularly supression of the immune system. It is also similar to the human
AIDS virus, and is sometimes referred to as cat AIDS. There is no evidence that
people can get AIDS from a cat that has FIV.
Only a small percent of cats in the U.S. are
infected with this virus. One of the most prevalent methods of
transmission is bite wounds in fighting cats, especially roaming
males. Kittens can possibly pick up the virus in the uterus and while
nursing.
This virus is easily killed by routine detergents
and disinfectants.
Stages
FIV has three clinical stages. The initial acute
stage occurs approximately four to six weeks after infection. It may
manifest as, but is not limited to, a fever, swollen lymph nodes, a
low white cell count or any combination of the above. Most cats
survive this phase without treatment. The second phase is a period of
relative normalcy lasting months to years. The third stage of the
infection results from a progressive destruction of the white blood
cells and dysfunction of the immune system.
Symptoms
A variety of clinical syndromes may develop, waxing and waning
for years or months until the cat succumbs. The most frequent finding is a chronic
oral infection of the gums, cheeks or tongue.
When a cat is
presented with gums that look like this it might have this
virus and should be tested to know for certain.
Cats may also acquire upper respiratory, eye,
ear,
or skin infections. Some cats may also show vague signs such as
lethargy, fever, diarrhea, poor haircoat,weight loss or inappetance
and a small percentage may develop cancer.
Diseases of internal organs
like the liver,
kidneys,
brain, lung, , and eyes are also
associated with FIV due to its immunosuppressive nature.
Diagnosis
We diagnose FIV the same way we diagnose every
disease, using a thorough
approach.
The approach to testing for FIV is similar to that of FeLV,
and follows the recommendations of the American Association of Feline Practitioners
and Academy of Feline Medicine advisory Panel. Their testing recommendations
are as follows:
The FIV status of every cat should be
known
Yearly testing should be performed on every
cat that goes outdoors or has exposure to an FIV positive
cat
Every sick cat should be tested, regardles
of previous test results
Every cat should be tested prior to entering
a new household, whether or not they have other
cats
When test results are negative but a recent
exposure is possible (ex.-a cat that fights and has wounds). These
cats should be tested at least 60 days after the last potential
exposure to allow time for the cat's immune system to develop
antibodies and show up as a positive test.
Our in-house test kit that checks for the
FeLV
also checks for the FIV virus. It is a screening test for antibodies
to the virus. If it comes back positive then a confirmation test
called the Western Blot test is needed to verify the diagnosis. On
occasion false positives can occur, so this verification test is
important. Kittens that have circulating FIV antibodies from nursing
their mothers might also test positive. They will return to a
negative state several months later, so they should be retested at 60
day intervals to make sure.
If the test comes back negative there is minimal chance a cat
has FIV. Since it takes 2-3 months (at least) for antibodies to show up in the
bloodstream once a cat gets infected by a bite wound, theoretically it is possible
that this is going on when a cat is tested negative. Also, in the later stages
of the disease when cats are actually showing severe symptoms the test can be
negative. This is because the immune system is so depleted at this point that
it can not make adequate antibodies to fight the disease, hence there are no
antibodies circulating in the bloodstream for the test to detect.
The 2 blue dots indicate a positive FIV test
on our in house test.
This same cat was
postive on its Western Blot test to confirm that is has FIV.
Notice the age of this cat on the top line of the
form.
Treatment
There is no medication that will
kill this virus. Treatment is aimed at keeping the immune system as
strong as possible and utilizing medication as needed. Fortunately,
the disease progresses slowly, and cats can remain healthy for
several years after being positively diagnoses. FIV positive cats
that are not showing any of the associated signs of illness should be
examined every 6 months at least. Routine blood panels, worm checks,
and urine samples should also be performed every 6 months.
Treatment of FIV revolves around the organ
or organs that are most affected. This means we routinely will use antibiotics
and immune stimulators. Your doctor will let you know if this applies to your
cat. Gum and mouth infections are treated by keeping the teeth
clean and the use of oral antibiotics.
As with any disease, good nutrition, routine preventive medical care, along
with plenty of TLC, are mandatory for a good quality of life. There is no evidence
that shows treating cats that are positive for the FIV test, but are not yet
showing symptoms, is of any benefit on the health or longevity of these cats.
Since this disease suppresses the
immune sytem in a manner similar to FeLV, therapy is similar. You can
find this therapy
in the FeLV page. The same caveats apply to both diseases in the use
of these medications. Treatment times for both FIV and FeLV cats
tends to be longer than cats that don't have these viruses. In
addition, the use of human aIDS medications have potential to help,
but they have greater side effects and are considered experimental.
also, their cost precludes their use in most budgets.
These cats are also susceptible to
food borne bacterial and parasitic diseases due to their
immunosuppression, so do not feed them raw or unpasteurized
foods.
All FIV positive cats should be kept indoors
to prevent transmission to other cats.
Prevention
This virus will not survive long in the
environment. Still, keeping your cats environment clean, and
routinely using bleach to disinfect feeding bowls etc., makes
sense.
Only introduce new kittens into your household if they are
healthy, free of internal or external
parasites, and are current on their vaccines. The best method of preventing
FIV (this also applies to the FeLV) is to prevent exposure in the first place.
FIV control is aimed at preventing exposure. It is best to keep cats indoors,
neuter male cats to reduce fighting and avoid introducing stray cats into a
household without prior FIV testing. Also, one should segregate FIV positive
cats from uninfected cats.
A vaccine has recently been developed, and it is too soon to
determine how well it works. A major disadvantage to the vaccine is the fact
that a cat that gets the vaccine will test positive on the FIV test.
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