Next time you jangle your keys within earshot of your cat, you might think twice, as scientists have found that high-pitched sounds could be hazardous to felines.
Researchers made the interesting discovery after investigating reports of cats suffering mysterious seizures.
Owners had told of their pets behaving strangely, apparently in response to random sounds such as the chinking of glass or jangling of coins or keys.
Some animals displayed involuntary jerking movements, while others lost consciousness or experienced episodes of "absence" during which they seemed unaware of their surroundings.
Experts identified a new syndrome, termed "feline audiogenic reflex seizures" (Fars).
A rare similar condition, audiogenic epilepsy, occurs in humans when seizures are triggered by sudden noises.
Writing in the Journal of Feline Medicine and Surgery, the researchers led by Mark Lowrie, from UK vet chain Davies Veterinary Specialists, concluded: "In gathering these data, the consistency of agreement between owners' responses has identified a degenerative syndrome of Fars in older cats.
"There appears to be no sex bias, although cats exclusively suffer from Fars later in life within their second decade.
"The sounds responsible are high-pitched sounds, often relatively quiet sounds, with increasing loudness and persistence of a sound only serving to enhance the severity of epileptic seizures."
"Work is ongoing to identify the genetic basis of this disorder," he added.
On average, cats were 15 years old when the seizures started. A third of those affected were from the Birman breed.
The scientists investigated cases involving 96 cats, some of which lost consciousness and experienced stiffening and jerking - often lasting several minutes.
Others suffered non-convulsive "absences" or "myoclonic seizures" - brief, shock-like jerks of a muscle or groups of muscles.
Common triggers for Fars included the sound of crinkling tin foil (82 cats), a metal spoon clanging against a ceramic feeding bowl (79 cats), chinking or tapping of glass (72 cats), the rustling of paper or plastic bags (71 cats), tapping on a computer keyboard or clicking a mouse (61 cats), jangling of coins or keys (59 cats), the hammering of a nail (38 cats) and even the clicking of an owner's tongue (24 cats).
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Less frequently reported were the sounds of mobile phone texting and ringing, digital alarms, the tearing of Velcro, running water, firewood splitting, and walking across a wooden floor with bare feet or squeaky shoes.
One owner reported a cat having a seizure after hearing the short, sharp scream of a young child.
Lowrie added that a second study, which is soon to be published, has identified the drug levetiracetam as an effective treatment for the condition.
"Our experience is that it can completely rid a cat of these sound-induced seizures, including the myoclonic twitches," he added.
Claire Bessant, chief executive of the cat charity International Cat Care, said: "How wonderful to be able to go back to those worried owners, who came to us for help with a problem previously unrecognised by the veterinary profession, with not only an explanation for their cats' behaviours but a way to help them as well."