After reaching nine and a half stone because of a rich diet of chicken dinners, what Mike the labrador needed was exercise.
But as he was too heavy for healthy runs in the park the only option left was plenty of walkies – in water.
The pet is now a slimmer six stone after a strict diet combined with seven months of training in a hydrotherapy tank – even though he was too large to fit in at first.
When he was taken in by a rescue pound after his owner died, three-year-old Mike was struggling to walk 100 metres - and damaged a ligament in his leg trying.
But after seven months on a strict calorie-controlled regime Mike has slimmed down to a svelte 38kg – just in time for the tail-end of summer.
Adoptive owners Hannah Holland and Paolo Terzaga swapped Mike's three daily human meals for two tins of bespoke dog food, and raw carrots for treats.
Ella Tonge, of Dogs Trust Loughborough, said: 'Mike was the largest dog we’ve had.
'He would eat pretty much anything.
'All the staff were so excited when we heard he was coming back into the centre.
'We’d heard that he had lost loads of weight but to see it in the flesh is amazing, he has a waist.'
Ella added: 'His plight highlighted the danger of over-feeding your pet and even worse feeding them a human diet.
'What is fine for us to eat is not for them, especially when combined with very little exercise.'
In February, partners Miss Holland and Mr Terzaga, both 29, took Mike for surgery to fix his leg. He now spends two hours a day walking, running and chasing after balls at his new home in Nottingham. The trimmer pup can finally fit into the hydrotherapy tank at the Dogs Trust Loughborough to treat his worn limbs.
Miss Holland, a veterinary student, said: 'Mike has always been such a bright and happy boy, even when he was nearly twice the size he should be.
'He just wanted to say hello to everyone and bounced around like a puppy.
'He’s still recovering from his ligament operation and has just started hydrotherapy at the Dogs Trust, something he seems to really enjoy.
'When he first arrived at Dogs Trust in early 2013 he was so large he couldn’t fit into the hydrotherapy tank
'But now with his new figure he is able to take full advantage of the tank and help rebuild his strength and ensure he is distributing his weight evenly.”
Mr Terzaga, a chartered accountant, added: 'He’s always had a great personality and hasn’t really changed much.
'He just seems happier that he can get around easier.'
By Daily Mail Reporter
PUBLISHED: 16:38, 5 September 2013