The United Kingdom-based charity International Cat Care
reached out to veterinary specialists after receiving surprising complaints
from cat owners: Their feline companions were apparently having seizures in
response to high-pitched sounds.
A study of these cats revealed that the sound-induced
seizures were more common in older cats, and the most common triggers were
crinkling tinfoil, hitting a ceramic bowl with a metal spoon and tapping glass.
Mark Lowrie and Laurent Garosi, veterinary neurologists at
Davies Veterinary Specialists in England, and Robert Harvey, a molecular
neuroscientist and geneticist at the University College London School of
Pharmacy, decided to survey cat owners about the phenomenon, which has been
dubbed "Tom and Jerry syndrome," after the cartoon character Tom, who
often responds to startling sounds with involuntary jerks. [Feline Fun: 10
Surprising Facts About Cats]
Hundreds of cat owners from around the world replied that
they had noticed their cats were having seizures in response to certain types
of sounds. Most owners' vets didn't know what was causing the seizures and
didn't believe a sound had been the trigger.
In a study published in the Journal of
Feline Medicine and Surgery, the researchers looked at data from 96 cats,
including the type of seizure, how long it lasted and what sound appeared to
trigger it. They found that some cats — like some humans — suffer from seizures
caused by sound, known as "audiogenic reflex seizures." In the cats,
certain sounds triggered absence (or nonconvulsive) seizures; myoclonic
seizures, characterized by brief muscle jerks; or generalized tonic-clonic
seizures, in which the animal loses consciousness and its body stiffens and
jerks for several minutes.
Both pedigree and nonpedigree cats can have these seizures,
but they were most common in Birman-breed cats. Seizures were also more common
in cats ages 10 to 19, and the average age of onset was 15 years, the researchers
said.
The sounds that triggered the seizures ran the gamut,
including crinkling tinfoil (82 cats), a metal spoon clanking on a ceramic food
bowl (79 cats), chinking or tapping glass (72 cats), crinkling paper or plastic
bags (71 cats), computer keyboard or mouse sounds (61 cats), jingling coins or
keys (59 cats), hammering a nail (38 cats) and the clicking of an owner's
tongue (24 cats). Less commonly, cellphone ringing, Velcro peeling or a walk
across a wooden floor with bare feet could trigger the kitty seizures.
Owners could sometimes prevent the seizures by avoiding
these sounds, but that wasn't always possible. Louder sounds also seemed to
make the seizures more intense.
The researchers have identified this cat version of
sound-triggered seizures as feline audiogenic reflex seizures, or FARS for
short. Future work will focus on the genetic basis of the disorder and how to
treat it.
The epilepsy medication levetiracetam can be an effective
treatment for managing FARS, and could "completely rid" a cat of
sound-induced seizures, the researchers said.
"How wonderful to be able to go back to those worried
owners who came to us for help with a problem previously unrecognized by the
veterinary profession with not only an explanation for their cats' behaviors,
but a way to help them as well," Claire Bessant, chief executive of
International Cat Care, said in a statement.
