At the rate he was eating, he was on the way to being the size of a hundred and one Dalmatians.
On a diet of chocolate and crisps, Barney's distinctive spots had swollen into great blotches, and he was carrying so much flab he could barely move.
When RSPCA inspectors raided owner John Green's home, the overfed dog tipped the scales at a mammoth 11st, double what he should have weighed.
Moving about left him out of breath almost immediately, and jumping in the air was an impossibility.
Yesterday, after 50-year-old Green was banned from keeping dogs for ten years, Barney displayed his new slimline figure, thanks to a healthy new diet and regular exercise.
Since he was taken into care in June, he has slimmed down to just over 6st, and he is now ready to go to a new home.
Inspectors seized eight-year-old Barney after Green, of Macclesfield, Cheshire, ignored warnings to stop overfeeding him.
Magistrates in the town heard that Green treated Barney more like a friend than a pet, regularly sharing fatty treats with him.
'When he had a packet of crisps, Barney had a packet of crisps,' said Andrew Meachin, prosecuting.
Along with regular bars of chocolate, Barney's food intake left him 'morbidly obese', and the dog was immediately seized by the RSPCA.
The court was told that unemployed Green 'thought the dog was a little overweight but did not know what weight he should be'.
His solicitor John Temperley said: 'The phrase "killing with kindness" comes to mind. He just overfed and overindulged his dog.'
Green admitted cruelty and was also ordered to complete 200 hours of unpaid work.
Afterwards, RSPCA inspector Rachel Andrews said: 'Hopefully this case will show pet owners just how vital it is to provide their animals with a carefully controlled diet and regular exercise.
'With Christmas just round the corner it might be tempting to overfeed them, but it's important to remember that those extra pounds can have a huge impact on their comfort, health and well-being.'
Earlier this year animal charity PDSA claimed 35 per cent of Britain's dogs were overweight, increasing the risk of arthritis, diabetes and an early death.
Pet owners now have a legal duty to provide proper care under the Animal Welfare Act. Breaches including feeding a cat or dog too much carry the threat of a fine of up to £20,000 or even 12 months' jail.
Anyone who wants to offer Barney a home should call the RSPCA's Warrington centre on 01925 632 944.
