Almost 80 per cent of vets believe that the number of fat pets is on the increase according to an RSPCA survey.
The society is warning that many animals are suffering from being overfed and says 76 per cent of vets practices now have special fat clinics.
Last year the RSPCA saw many overweight animals ranging from dogs and cats to horses, donkeys and even a parrot!
Their survey also revealed that vets think many owners are surprised when they're informed their pets are obese.
RSPCA vet David Grant said: "Feeding your pet full English breakfasts, chocolate, chips, burgers and too much pet food may make you feel like a kind and loving owner.
"But it may give your pet fatty tumours, diabetes, arthritis, high blood pressure, liver failure, skin problems and even an early death."