Do Shih Tzus Have Underbites?

The Shih Tzu weighs between 9 and 16 pounds with a height between 9 and 10 inches at the shoulder. Shih Tzus are of Chinese origin and are considered to be one of the 14 oldest dog breeds. There is evidence that dogs existed in China going back to 8,000 B.C. Shi Tzus were initially bred for the purpose of being companions. Shih Tzus are difficult to housetrain and are prone to eating their own feces. Families with small children are cautioned against having a Shih Tzu as a pet due to the increased likelihood of unintentional injury occurring to the dog.