Video report by ITV News reporter Ivor Bennett

A dog that used to eat whole Sunday roasts has become pet slimmer of the year after losing over a third of its body weight.

Oscar the Cavalier King Charles Spaniel was morbidly obese just six months ago after weeks of comfort eating following the death of his owner.

The 10-year-old hit a whopping 3st 6lb - 80% over his ideal weight - and as a consequence faced serious health problems and a shortened life span.

His owner's daughter then enrolled Oscar on a pet slimming course where the pooch returned to a healthier 2st 1lb following weeks of training.

And now he has won PDSA's pet slimmer of the year, beating off stiff competition from other dogs and a rabbit named Pebbles.

Karren Allen told Good Morning Britain that her mother, Oscar's owner, started "comfort feeding" when she became a widower.

But Ms Allen said the over-indulgence was a much longer-term problem, as one of Oscar's favourite meals was a traditional Sunday dinner - with all the trimmings.

"Dad used to do all the cooking, and dad used to do Sunday roasts just for Oscar", Ms Allen explained.

"He would have everything".

She added: "You look at your pets. You love them to bits and they've only got to look at you with those little eyes and it's like 'there you go'".

Oscar used to be fed whole Sunday roasts by his owner Credit: GMB

When Oscar enrolled in PDSA's annual Pet Fit Club he was morbidly obese and could only manage 15 seconds a time in the swimming pool.

After every paddle the trainer would have to grab on to Oscar to prevent him from going under.

But having lost enormous amounts of weight, Oscar now "loves" jumping into the pool and can even manage a 10-minute swim without a break.

PDSA vet Paul Manktelow warned that over-eating and leftovers were one of the biggest downfalls for dogs - leaving many dangerously overweight.

He explained that a packet of crisps is equivalent to two big steak pies for a dog.

A slice of toast is the same of a bag of chips; three pieces of cheese equivalent to two cheese burgers; and a tin of tuna the same as 35 chicken nuggets.

Credit: GMB

Credit: GMB

Credit: GMB