Dogs may become overweight for many reasons. Regardless of the cause of obesity, the owner is ultimately responsible for regulating the dog's caloric intake and use, and in seeking veterinary assistance in maintaining the dog at the optimal weight.
Humans are the main cause of obesity in dogs.
Some of the more common diseases and conditions which can contribute to obesity in the dog are discussed below. Others will eat as much as is available and then look for more. Some dogs are finicky and others will eat just about anything. So the amount and type of food that is fed and the eating tendencies of the dog can determine how likely it is a dog will become overweight. The type of food fed has a direct bearing on the tendency of a dog to become overweight.