FIP—THE PURRING DISEASE
© Amy D. Shojai, www.shojai.com
One of the most confusing and
frightening health issues facing pet cats today baffles pet owners, cat
breeders, and researchers alike. Feline Infectious Peritonitis (FIP) kills cats
of all species, from house pets to lions.
It affects very young or very old cats.
Although a vaccine is available, experts disagree on its effectiveness and
benefits. Routine use remains very controversial.
Sadly, perfectly healthy cats are
euthanized when so-called “FIP tests” are misinterpreted. There is no
test available to prove your cat has FIP. The only definitive test for FIP
must be performed on tissue samples taken after the cat has died.
The confusion arises because common
tests measure the “titer” (levels of immune components) in the cat’s
bloodstream. Cats are susceptible to Feline Enteric Coronavirus (FECV), Canine
Coronavirus (CCV), and a virus that normally affects swine called Transmissible
Gastroenteritis Virus (TGEV).
Different labs offer variable
interpretations of what constitutes a “negative” or “positive” Corona
titer level. Your kitty may test positive from one lab, and negative from
another using the same sample. A positive titer simply means exposure took place
and one of these viruses left a fingerprint (antibody) behind. It does not mean
Kitty has FIP, nor does it predict a cat will get sick.
In fact, experts estimate that up to 90
percent of pet cats are exposed to a Corona virus during their lives. Immunity
doesn’t last very long, though, and cats continuously infect and re-infect
each other particularly in multiple cat environments. For that reason, cats from
shelters, catteries, feral colonies and the like are at highest risk.
Another test, RT-PCR (Reverse
Transcriptase-Polymerase Chain Reaction) offered by some commercial laboratories
measures the amount of virus shed in the feces. Cats do transmit Corona virus to
each other through infected feces or saliva, but shedding cats aren’t
necessarily sick with FIP.
Correlation between fecal shedding and
FIP hasn’t been proven. Only one out of ten Corona infections results in FIP.
On top of that, the RT-PCR tests often are wrong because a single molecule can
corrupt the test and cause false positives and false negatives.
The next part of the puzzle sounds like
science fiction. FIP develops when the harmless form of Corona virus
infects a cat, and later mutates into a monster—and then the cat’s
over-enthusiastic immune response ultimately kills. In a very real sense, each
FIP virus is unique to that individual cat. Direct cat-to-cat transmission of
FIP is rare.
Once FIP virus passes through the
intestinal wall into the bloodstream, infected white blood cells turn into virus
factories and carry their lethal cargo everywhere. A variety of symptoms
develop, depending on which organ(s) become infected. Finally, the cat’s
immune response speeds up destruction of the tissue.
The “effusive” form causes leakage
of fluid into the abdomen, which swells with a straw-colored liquid. However,
symptoms can be vague to severe, and mimic many other diseases. Without specific
tests, veterinarians must be pet detectives and rule out other causes before
suggesting a diagnosis of FIP.
There is no cure for FIP. Treatment focuses on making the cat comfortable
for as long as possible. Often the disease has been called the “purring
disease” because cats purr up to the moment of death—in an effort to comfort
themselves and ease the pain.
If you lose a cat to FIP that does not mean other cats in your
care will become ill. The FIP virus arises as the result of a mutation, and
can’t be predicted or prevented. Even the most fastidious and caring cat
owners, shelters, and breeders lose cherished cats to this disease. An “FIP
Guarantee” from a reputable cat breeder simply means the kitten/cat will be
replaced should he become ill—not that he won’t get the disease.
Researchers and caring cat owners today
work very hard to better understand (and someday prevent) FIP. Protect your cat
by educating yourself. Partner with your veterinarian for the best care
possible. Read more about FIP at http://www.orionfoundation.com/
A technical article is available at http://www.vetscite.org/issue1/reviews/txt_index_0800.htm
I encourage you to print out/copy this column and other information about
FIP, and talk further with your own veterinarian about any concerns.
Amy D. Shojai, www.shojai.com
D. Shojai is a nationally known pet care specialist, and author of more
than a dozen pet books, including “Complete Care for Your Aging Cat.”
She can be reached through her website www.shojai.com