What is Feline
Immunodeficiency Virus?
Known as FIV or
cat AIDS, FIV is an infectious disease caused by a
retrovirus belonging to the lentivirus family. It is in
the same family as the FeLV virus, and is similar to the HIV
virus in humans. FIV infects both domesticated cats, lions,
tigers, pumas & cheetahs.
FIV attacks the
cells of the immune system, leading to FAIDS (feline
acquired immune deficiency syndrome). This compromises the cat's
ability to fight off infections.
It was first
discovered in 1986 in a colony of cats in California, and is
found worldwide.
What is a
virus?
A virus is a
ultramicroscopic infectious agent which consists of either DNA
or RNA wrapped in a protein coat. It is only able to replicate
inside living cells. The phrase "a piece of bad news wrapped in
protein" is a very well known saying regarding viruses.
Viruses are not
living organisms, they don't respirate, process nutrients or
generate waste products.
What does FIV
do & what are the symptoms?
FIV attacks the
cat's immune system which makes it vulnerable to secondary
bacterial, viral, fungal & protazoal infections.
Stage 1:
Once inside the
body, FIV is carried to the regional lymph nodes where it
replicates in the white blood cells known as T lymphocytes (CD4+
lymphocyte). It then spreads to other lymph nodes throughout the
body. At this time there may be an acute illness which is
characterised by fever,
leukopenia, anaemia,
malaise & swollen
lymph nodes, lasting a few weeks. During this initial stage it
may go unnoticed that the cat is unwell.
Stage 2: This is the asymptomatic phase which can
last for many years. During this stage cat appears healthy & is able to lead a
normal life.
Stage 3: As we've already discussed, FIV destroys the T
lymphocytes, these cells are required for the proper functioning
of the immune system. Eventually
when enough T lymphocytes have been destroyed, the immune system
loses it's ability to fight off opportunistic infections &
signs of immunodeficiency develop. Cats
show a range of symptoms in this stage, these symptoms may vary
from cat to cat. Some of which may include:
How is FIV
transmitted?
The virus is
present in large quantities in the cat's saliva, and the most
common mode of transmission is via bite wounds. Free roaming,
entire male cats are at greater risk as they are more likely to
become involved in territorial fighting. Occasionally
FIV is passed onto kittens who's mother is FIV positive. This
may happen either in utero or via infected milk.
Cats don't become
infected via mutual grooming, nor will the act of mating,
although the biting that goes along with mating may pass on the
virus.
How is FIV
diagnosed? FIV
is diagnosed based on history, clinical signs & a blood test
known as ELISA (enzyme-linked immunosorbent assay), which
detects antibodies to FIV. It is possible to get false positive
or false negatives from these results for the following
reasons: False
positive: If
a cat has received the FIV vaccine it will have a positive test
result. Kittens
born to FIV infected mothers may have received antibodies from
their mothers milk. This doesn't mean that the kitten has FIV,
just that it's received antibodies to FIV. Kittens who test
positive should be re-tested at a later date. False
negative: It
usually takes several weeks for antibodies to FIV to appear in
the blood, if the cat is tested prior to this it will show a
negative result. If
the cat is in the later stages of infection it may not be
producing antibodies. A
FIV PCR (polymerase chain reaction) test is available in some
commercial laboratories. PCR detects the presence of the FIV
virus in the blood. Western
blot test or IFA (Immuno-Fluorescent Antibody Test): If a cat
has tested positive to FIV it is sometimes recommended to follow
up with either a Western Blot Test or an IFA test.
If your cat has
tested positive to FIV but you are not sure if it has had the
vaccine, or want to be sure it does/doesn't have the virus then
you may be able to request a PCR (polymerase chain reaction)
test, which will be able to detect the presence of FIV DNA in
the blood.
How is FIV
treated?
There is no cure
for FIV, once a cat has it, it's for life. The goal is to
provide supportive care to the infected cat. This may
include;
-
Regular
veterinary check ups.
-
Maintaining
proper parasite control.
-
Ensuring
that prompt veterinary attention is sought at the first sign
of illness.
-
Feed
a high quality diet.
-
Limiting
their exposure to disease by keeping them indoors & away
from neighbourhood or stray cats.
-
The
use of anti bacterial & anti fungal drugs
-
Maintain
a proper vaccination regime to protect your cat from other
infectious diseases.
-
Blood
transfusions may be necessary in stage 3.
-
High
calorie supplements may be necessary in stage 3.
-
There
are other drugs available such as interferon & AZT which
have been used in some cats, but it is best to speak to your
veterinarian about these.
Should
I have my FIV positive cat euthanised?
No,
this isn't necessary. FIV positive cats can live for many years,
especially if they are given prompt medical attention when
necessary & supportive care.
Prevention of
FIV:
Desexing of all
pets, not allowing them to free roam & testing all cats used for
breeding.
There is now an
FIV vaccine which is available, it isn't 100% effective. Cats
given the vaccine will test positive to FIV which may result in
confusion, especially in the case of a cat being picked up by a
shelter or council. For further information on the vaccine,
read here...
Which cats are
most at risk of FIV?
Un-neutered, free
roaming males are at the greatest risk of FIV. Any cat allowed
to free roam is at risk of catching FIV.
Can FIV
positive & FIV negative cats live in the same household? The
general opinion is yes, this is okay as long as there isn't any
fighting between the cats. As FIV positive cats are more
susceptible to opportunistic infections it is important to
ensure the health & vaccination status of ALL cats in the
household. Others
suggest either keeping FIV positive cats isolated from FIV
negative cats or rehoming the FIV positive cat in a single cat household.
Your veterinarian is the best person to speak to in this
regard.
Can I catch FIV
from my cat?
No it is not
possible to catch FIV from your cat, nor is it possible for your
cat to catch HIV from a human. While both viruses come from the
same family, they are species specific.
Please note:
The medical
articles on this site have not been written by a veterinarian &
should not be considered a replacement for a veterinarian visit.
The articles are provided for informative purposes only.
Always seek
immediate veterinary advice for any problems (health or
behavioral) in your pets.
While great care
has been made in the creation of these articles, we cannot
guarantee the accuracy or omissions on these pages. If in any
doubt whatsoever, seek professional medical advice.
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