A BEAGLE who used to stop halfway up the stairs because he was too fat has been named as Britain's biggest loser in a pet slimming competition.

Alfie lost more than a third of his weight in just six months, going from a whopping 4st 10lb (30kg) down to just over 3st (20kg).

His new slim figure means Alfie has much more energy and is constantly wagging his tail, owner Emily Simcox, 25, from Middlesbrough, said.

Alfie won the Pet Fit Club competition run by the PDSA vets charity, beating Lola the rabbit, from Derby, who lost almost a quarter of her body weight.

Ms Simcox took Alfie to her local PDSA for help because he looked sad at being overweight.

He was fat when she adopted him five years ago and she admitted giving him treats to show she loved him, adding: "Those eyes are hard to resist."

She said: "Before, he was sluggish, tired and looked sad a lot of the time.

"He couldn't even walk up the stairs; he'd struggle halfway up and then had to stop for a rest before getting to the top.

"On walks, he would sluggishly walk towards a ball we'd thrown and often wouldn't bother even trying to bring it back.

"But since being on the diet his tail hasn't stopped wagging.

"He leaps and bounds, and is so full of energy."

Alfie's transformation came by sticking to a strict diet and his owner showing tough love by learning to say no when he demanded food.

Not that it all went smoothly, Ms Simcox said.

"I was making a cheese sandwich and left it on the kitchen counter," she said.

"I walked back in the room to find Alfie licking his lips, and the cheese sandwich gone."

She urged other pet owners to seek help if their animal is overweight.

She said: "Alfie is proof that change is possible - we'll never look back."

Alfie's weight loss was supervised by PDSA vet nurse Steph Williams, from Middlesbrough PDSA Pet Hospital.

She said: "He is unrecognisable from the dog that waddled into our hospital for his first weigh-in six months ago.

"He's much healthier and will be able to enjoy a much happier life."

PDSA vet nurse Katy Orton, who helped to judge the competition, said up to 40% of cats and dogs in the UK are fat, but help is available.