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. Bulldogs are one of the few breeds whose tail is naturally short and either straight, screwed or thin and thus is not cut or docked as with some other breeds. A straight tail is a more desirable tail according to the breed standard set forth by the BCA if it is facing downward, not upwards. Generally, Bulldogs are known for getting along well with children, other dogs, and other pets.