Feline Hyperesthesia Syndrome
Feline Hyperesthesia Syndrome (FHS), or cat schizophrenia,
is a behavioral disorder characterized by extreme levels of
bizarre behavior. While all cats will act strangely from time
to time—staring at thing that aren't there or running around
quickly for no obvious reason, for instance—in extreme
cases this behavior becomes dysfunctional and is
categorized as the syndrome feline hyperesthesia.
Symptoms:
FHS causes extreme character changes. Cats with this
disorder may act manic or schizophrenic; they may seem to
hallucinate. Symptoms include:
Frantic grooming of the flank and tail, often leading to hair
loss
Dilated pupils
Fixation with the tail, often manifested as swishing of the tail,
chasing of the tail or attacking the tail
Bouts of hyperactive or aggressive behavior
Rippling of the skin
Apparent hallucinations
Loud vocalizations
Sensitivity to touch along the spine; often, stroking of the
spine leads to bouts of strange behavior
Mood swings
Seizures
Bouts of FHS behaviors occur frequently in cats that suffer
from this disorder. They may experience bouts of strange
behavior once every few days, or constantly.
Causes:
Vets don't really know what causes FHS, but they have
some ideas.
Some cats have seizures during or following an attack of
FHS. This leads some vets to believe that FHS may be
caused by abnormal electrical activity in the part of the brain
that controls emotions, grooming, and predatory aggression.
Some cats with FHS respond to anti-convulsant therapy, a
fact that lends weight to this theory.
Some vets believe that FHS may be a type of feline
obsessive-compulsive disorder, causing cats to worry
obsessively about grooming, predatory behaviors, and
personal safety. Because FHS grooming behaviors emulate
obsessive-compulsive disorder and because some cats with
FHS respond well to anti-anxiety medications, there may be
some truth to this theory. Some vets believe that FHS is a
combination of both of the above. They point out that
abnormal electrical activity in the brain leads to seizures,
which then in turn lead to obsessive-compulsive thoughts
and behaviors. This explains why both theories appear to be
true to some extent.
Vets have found that FHS appears to be linked to stress.
They also believe there may be a hereditary component to
the disease. Some breeds, especially Oriental ones, seem
predisposed to developing FHS.
Some cats with FHS have been found to have lesions in
their spinal muscles. While vets believe that these lesions
may contribute some how to FHS, they aren't sure exactly
what role they might play.
Diagnosis and Treatment:
There's no definitive test for the diagnosis of FHS, but if your
vet is able to rule out medical causes of the above behaviors
and if your cat responds to FHS treatment, a diagnosis of
FHS is made.
Treatment involves anti-anxiety and anti-depressant
medication, as well as anti-convulsant medications. You
should also do everything possible to give your FHS cat a
stress free environment. You should make sure your cat
gets plenty of exercise; feed him on a regular schedule;
teach him tricks, and spend more time with him. If there is
tension between your FHS cat and other cats or pets in the
home, do your best to minimize it.
Outcomes:
Because some vets believe FHS is hereditary, cats
diagnosed with FHS should not be bred. If your cat
progresses to the point of aggressive behavior towards
humans and/or seizures not controlled by medications, most
vets will recommend euthanasia.