Download Feline Infectious Peritonitis

Feline Infectious Peritonitis:
Interpretation of a Positive Laboratory Test for Virus Antibody in a Healthy Cat
My cat has tested “positive” for FIP on a blood test, but seems healthy. Is he/she actually sick?
The early signs of FIP disease can be quite vague and may not be obvious. If your cat appears to be in good health and
has been examined by a veterinarian, then the “positive test” means only that your cat has been exposed to a virus in the
Coronavirus family (there are three in cats, grouped into a name abbreviated as FeCoV) that can cause FIP. The
laboratory test has detected antibodies that your cat has produced to one of these three viruses in the FeCoV family and
does not mean that your cat has FIP unless there are other abnormal laboratory tests or clinical signs present. Further
testing can be done with fluid from the chest or abdominal cavities (called a Western Blot Test confirmation) to further
rule in or rule out the suspected diagnosis of FIP. This test cannot be performed unless the fluid is accessible (this special
test cannot be run with a blood sample).
Is the virus still present, and will my cat actually become ill?
Normally, the presence of antibodies means that the virus infection has been cleared, but with the Feline Corona viruses
the virus may persist even in the presence of antibodies. The test does not tell us if the virus is still present in your cat,
only that it was exposed. Retesting the blood after a month can determine if the viral antibody response is active or is
now dormant (another blood titer level to check of the antibody levels are rising or not). Even though a cat tests positive
for antibodies, it is impossible to predict which cats will develop FIP disease. There is a risk, but many cats that test
“positive” for the FIP titer level are otherwise healthy, and live out normal lives. Even if FIP were to develop in your cat, it
could be months or even years before clinical signs and symptoms occurred.
What can be done to prevent FIP?
There is a vaccine for FIP but there is no evidence that this would help alter outcome in a cat that is already “positive” for
antibody. It is probably best not to vaccinate a “positive” cat. Unfortunately, there is nothing that can be done to affect
the outcome. It depends on complex factors including genetics, the strain of Feline Coronavirus (most strains are
relatively harmless), and so on.
What are the first signs of FIP that I should look for?
The first signs of FIP may be very vague – listlessness, lethargy, respiratory signs, decrease or absent appetite, and/or
variable fever. After a period of several days or a few weeks other signs will develop such as weight loss or vision
changes. The most typical sign is an accumulation of fluid in the abdomen giving a bloated appearance (“wet” form of
FIP). Similar fluid accumulation in the chest cavity may result in difficulty breathing. But in some cats there is little or no
fluid accumulation in body cavities, but there is inflammation within a variety of organs such as liver, intestine wall, eyes,
and brain. This is the “dry” form of FIP. Usually symptomatic cats succumb to the disease over time; it is considered an
incurable disease although some cats have responded positively with supportive, chemo, and immune therapies.
What should I do?
Make sure that your cat is receiving regular veterinary check-ups. Remember that infections with Feline Coronaviruses are
common (up to 30% of all cats) but FIP disease is uncommon (less than 1% of cats admitted to veterinary hospitals) and
if your cat appears healthy at this time, it is less likely that your cat will not develop FIP disease. It is not certain that your
cat is still carrying or shedding virus and therefore it may not be infectious to other cats. Even if your cat is infectious, the
strain of virus it is shedding may be a Coronavirus strain that is not normally associated with causing FIP. Also, a high
portion of cats that your cat will come into contact with have already been exposed to some strain of Feline Coronavirus
and are healthy/not shedding virus to other cats. Therefore you should not be unduly concerned about occasional contact
with other cats. Because kittens and young cats up to about 6 months may be more susceptible, it would be advisable to
prevent contact with that age group. At CMCEH we do use an intranasal FIP vaccine available on the market for cats in
higher risk lifestyles; we will assist you in determining your cats Lifestyle Risk Category and his/her vaccine requirements
to stay healthy for a lifetime. ☺