Also called the Boston Bull, the breed was developed in Boston, Massachusetts from a cross between the English Bulldog and the now extinct English White Terrier. This small but well-muscled dog has a short body with a square appearance. Its head is flat on the top and the muzzle is free of wrinkles and has a square appearance because the bite is either even or slightly undershot. It has small, erect ears which are either cropped or left natural, short but straight and muscular limbs, a broad chest and a slightly arched neck. It has a short, fine coat that is distinctive in colour: it has white markings that are in proportion to either black, seal, brindle or the combination of the three. Seal is a kind of colour specifically used for the Boston Terrier and it is black with red highlights when viewed in bright light.
This non-sporting breed was originally bred for fighting, but has been bred down for human companionship. Gentle, friendly and alert, the Boston Terrier has a well-balanced temperament and they are easy to train. However, because they do have a strong personality, Boston Terriers can be high-strung and rambunctious when not provided with proper training and physical and mental activities. Sociable dogs that they are, they are especially good with the elderly and the children. Very affectionate and playful even with other non-canine pets. Because they are short-haired they are prone to extreme weather conditions and may have breathing difficulties in hot or cold temperatures. They have a life expectancy of 15 or more years.