London - They are the ultimate in designer pets – cute, cuddly cats with legs so short that they have been dubbed the dachshunds of the feline world.
Known as Munchkin cats, they have become a sought-after pet, with demand fuelled by online videos of their antics, and by high-profile owners such as Paris Hilton, who named hers Shorty.
But their distinctive appearance is down to a defective gene which means they cannot run or jump properly, and which can lead to other serious health problems.
Vets say that to breed cats with such a physical deformity is cruel and have urged animal-lovers not to add to the growing trade.
Andrew Prentis, of Hyde Park Veterinary Centre in Central London, said: "Why would you want to breed a cat that effectively doesn’t have any legs? If you want to see a short-legged cat go and watch a cartoon. Leave the cat alone."
The Governing Council Of The Cat Fancy, the leading body for registering cats in Britain, has refused to recognise the breed.
Director Rosemary Fisher said: "It is distressing to see kittens and puppies bred simply for the cuteness factor, or following the trend for designer breeds kept as a fashion statement."
She added: "We are against the breeding of any breed or variety of cats whose physical structure could affect its welfare."
Nevertheless, The Mail on Sunday found Munchkin kittens for sale on the internet, priced between £650 and £900, from breeders in London and Nottingham.
"People want something different, but Munchkins have a range of potential physical problems," Fisher added.
"Some Munchkins, for example, suffer from lordosis, a condition in which spinal muscles grow too short, causing the spine to arch inwards. This may cause early death in kittens, or shortness of breath during physical exertion in an adult."
Other experts insist that the deformity does not create worrying health risks, although they acknowledge that the breed has an odd way of walking and also struggles to jump on to high surfaces because of its stunted limbs.
The Munchkins’ legs may be very short but they are usually well muscled and straight, although the paws are slightly turned out. The tail is set high to balance out the short legs. They are sometimes said to resemble a squirrel as they love to sit on their haunches with their front paws held up, all contributing to the cuteness of their image.
Named after the characters in The Wizard Of Oz, the Munchkins originated as a mutation in a litter born in Louisiana in 1983. The mutant gene is sometimes known as the ‘lethal’ gene because if two Munchkins breed, their kittens are unlikely to survive. Mr Prentis said breeding Munchkins to encourage that mutation was wrong: ‘It’s deliberately breeding an animal against natural evolution – and that is never a good idea.
"The cat in its natural form has evolved over thousands of years to be pretty well designed and to be very efficient, healthy and athletic.
"The idea that someone wants to breed them to have effectively no legs, and for entirely cosmetic reasons, is very disappointing."
He added: "We also deal with many dog breeds that have inherited deformities, such as dachshunds and bulldogs, and many of them have significant problems."
Munchkins have divided the cat world. The International Cat Association, which sanctions cat shows, granted the Munchkin "new breed" status in 1995 and championship status in 2003. But the Cat Fanciers’ Association, the world’s largest registry of pedigreed cats, does not recognise them, which means that pet shops are unlikely to sell them.
The charity International Cat Care says that as well as affecting mobility, "in some cases leg deformities may be painful and debilitating through the development of abnormal joints". It adds: "Munchkins may not have the flexibility to groom themselves as well as other cats do."
The lifespan of Munchkins ranges from 12 to 15 years, in line with most domestic cats. Lilliput, a tortoiseshell Munchkin cat living in California, holds the record for the shortest living cat, at just over 5 in from its paws to shoulder.
Extremes of dog-breeding have long proved controversial, with fears of disease and deformities allegedly caused by inbreeding.