Weight is divided by classes as follows:
The length of leg must balance with the length of body to give the Boston Terrier its striking square appearance. The Boston Terrier is a sturdy dog and must not appear to be either spindly or coarse. The bone and muscle must be in proportion as well as an enhancement to the dog's weight and structure. Fault: Blocky or chunky in appearance. Influence of Sex. In a comparison of specimens of each sex, the only evident difference is a slight refinement in the bitch's conformation.