"He will walk when he has to. But when the owner is standing and talking, he sits down whenever he can, and he gets out of breath quite easily."
Carrying too much weight gives dogs, especially big dogs, problems with their joints and the ligaments in their back legs. Obese cats and dogs also get early arthritis, diabetes and heart conditions and they are not as easy to treat as people.
Owners think feeding their pet will make it happy, Miss Ratcliffe said, but overfeeding could spoil its quality of life.
Some breeds were prone to plumping up such as pugs, labradors and rottweilers.
Busy people and elderly people were also less likely to take their dogs for walks.
Automatic feeders were especially bad for cats, Miss Ratcliffe said. As predators they would normally eat after a kill, and not hunt again until they were hungry.
In Vets on Carlton's weight loss competition, pets will be weighed and photographed regularly. They will spend six months eating a new dog or cat food that's high in protein and fibre.