London - About half the dogs and a third of all cats in Britain are too fat, a veterinary charity warned Thursday.

Worse: most pet owners don't notice that their four-legged friends are packing too many pounds.

According to the People's Dispensary for Sick Animals, only a fifth of cat owners are aware that their pet has a weight problem. That applied to only a third of dog owners.

Since so many dogs and cats are overweight, pet owners have unrealistic perceptions of the ideal weight and shape for their pet, said veterinarian Sean Wensley.

He advises pet owners to check their pet's weight by hand.

If you can no longer feel your pet's ribs or spine, the animal is overweight. (dpa)