Jack the dog

The 2012 "Pet Fit Club" was a six-month weight loss program and competition for pets overseen by the U.K. veterinary charity PDSA. PDSA provides free veterinary care to sick and injured pets of people in need, and promotes responsible pet ownership. Their network includes 50 PetAid-associated hospitals and nearly 380 PetAid associated vet practices.

This year's Pet Fit Club winner was Jack, a Cavalier King Charles Spaniel who found a new home this year.

Starting weight: 45.2 lbs

Percent overweight: 105 percent

Ideal weight: 22 lbs

Credit: PDSA