Bulldog,  also known as the British Bulldog or English Bulldog, is a medium-sized dog breed. It is a muscular, hefty dog with a wrinkled face and a distinctive pushed-in nose. The Kennel Club (UK), the American Kennel Club (US), and the United Kennel Club (US) oversee breeding records. Bulldogs are popular pets; they were the fifth most popular purebreed in the US in 2017 according to the American Kennel Club. Like all dogs, Bulldogs require daily exercise. If not properly exercised it is possible for a Bulldog to become overweight, which could lead to heart and lung problems, as well as stress on the joints.