<P> In the early years, the color and markings were not very important . By the 20th century the breed's distinctive markings and color were written into the standard, becoming an essential feature . The Boston Terrier has lost most of its aggressive nature, preferring the company of humans, although some males will still challenge other dogs if they feel their territory is being invaded . Boston University's mascot is Rhett the Boston Terrier . The Boston Terrier is also the mascot of Wofford College in Spartanburg, S.C. </P> <P> The Boston Terrier is a compactly built, well - proportioned dog . It has a square - looking head with erect ears and a slightly arched neck . The muzzle is short and generally wrinkle - free, with an even or a slightly undershot bite . The chest is broad and the tail is short . According to international breed standards, the dog should weigh no more than 25 pounds (11 kg). Boston Terriers usually stand up to 15 - 17 inches at the withers . </P> <P> The American Kennel Club divides the breed into three classes: under 15 pounds, 15 pounds and under 20 pounds, 20 pounds and not exceeding 25 pounds . </P> <P> The Boston Terrier is characteristically marked with white in proportion to either black, brindle, seal (color of a wet seal, a very dark brown that looks black except in the bright sun), or a combination of the three . Any other color is not accepted as a Boston Terrier by the American Kennel Club, as they are usually obtained by crossbreeding with other breeds and the dog loses its characteristic "tuxedo" appearance . </P>

What type of dog is a boston terrier