Binge eating and a couch-potato lifestyle is fuelling a four-legged obesity crisis, say vets amid the launch of a slimming competition for pets.

The competition includes a 22 pound cat named Elvis Presley - who's twice the size of a normal feline - and Alfie the Jack Russell who enjoys steak sandwiches.

There's also a 28 pound Maltese Shih Tzu who loves cheese on toast.

Chosen pets are placed on a strict six-month diet and rigorous exercise programme overseen by vets by charity PDSA.

Elvis, from Scotland, bulked up by snacking on an ‘all day buffet’ courtesy of his devoted owner and super-sized Alfie, who is more than double his ideal weight, devours nuts and pork scratchings.

The national competition, in its 13th year, has helped 124 overweight and obese pets lose 994 pounds.

That's equivalent to a grand piano or 160,000 doughnuts and last year's winner, Alfie the Beagle, shed an 34% of his bodyweight.

Up to 15 overweight dogs, cats and rabbits from across the UK will be chosen to participate in Pet Fit Club this year.

Elvis' owner Carole Sweeney, 55, says she didn’t realize how big her boy had become until comments from family and friends left her ‘all shook up.’

Sweeney, a huge Elvis fan who has a collection of his posters and LP’s from her teenage years, said the concerns about her beloved Burmese prompted her to take him to the vets for a check-up.

She’d been caught in a trap of feeding Elvis too much out of love.

Sweeneysaid: “I never gave Elvis treats or human food, but I’ve since learned that his portion sizes were way out of control.

“He basically had his own all-day buffet, whenever he emptied his bowl I would fill it back up again. The fact that he’s an indoor cat meant he soon piled on the weight.

“Thanks to the expert advice from the vets and nurses at PDSA, he’s now being fed a special diet food and I weigh out his portions so I know exactly how much he’s eating.”

PDSA vet Rebecca Ashman said: “Sadly the UK’s pet population is suffering from an obesity epidemic.

"Latest scientific literature shows that at least a third of dogs and a quarter of cats are clinically overweight or obese, but the true figures could be as high as 40%, making obesity one of the most common medical diseases seen by vets.

“Prevention is definitely better than cure, but if owners are worried about their pet’s weight it is never too late to do something about it.

"With the right advice, a good diet, suitable exercise and a bit of willpower owners have the ability to make a real difference to their pet’s health, happiness and life expectancy."

The charity’s PAW Report revealed that 5.7million UK pets (3.4 million dogs, 2 million cats and 260,000 rabbits) are fed treats every day.

Owners confessed that these ‘treats’ often include crisps, cake, cheese, chips, takeaways – even chocolate, which is highly toxic to dogs and can be fatal.

They also admitted that their pets regularly dined on table scraps or leftovers – some 4 million (2.4 million dogs, 1.5 million cats and 30,000 rabbits) receive these as their main meals instead of suitable pet food.