TJ, a Staffordshire bull terrier from Edinburgh, and Nyah, a cocker spaniel from Glasgow, finished second and third respectively in the competition run by veterinary charity PDSA.
The pair each lost almost a quarter of their body weight after a six-month diet and fitness regime.
Fifteen-year-old TJ’s weight problem began with a leg injury sustained while chasing a cat in the garden several years ago. She struggled to walk and ended up tipping the scales at 5st 5lb, around 70% over her ideal weight.
TJ has since shed more than a stone and lost nearly six inches of flab from her waist.
Owner Katy Visentin, 64, said: “I can’t believe the difference in her, she’s like a different dog. Her coat is all glossy and shiny, she’s got a wet nose and she seems to have more energy than she’s ever had. It’s just a joy for me to see her like this.”
Nyah weighed 4st 8lb when she began the programme in May and is now 3st 9lb, shedding just under a stone and also losing six inches from her waist.
Owner Catherine Jeng, 69, said: “It’s been a truly amazing journey and I can’t believe the change in Nyah. She’s almost unrecognisable. She’s a lot livelier and she’s walking with a spring in her step. She’s a completely different dog.”
A total of 16 obese cats, dogs and rabbits were chosen for the charity’s Pet Fit Club with Ruby, a Jack Russell terrier from Sunderland, named as the national winner for losing a third of her bodyweight.
Elaine Pendlebury, PDSA senior veterinary surgeon, said: “Many people fall into the trap of overindulging their pet with food as a way of expressing their love.
“Katy and Catherine have worked really hard with their pets and have shown that it’s never too late to make a positive change. With help from PDSA and lots of determination they have completely changed TJ and Nyah’s lives.”