Shih Tzu (shē dzōō), breed of active, alert toy dog originating in Tibet centuries ago. It stands from 8 to 11 in. (20.3–27.9 cm) high at the shoulder and weighs from 9 to 18 lb (4.1–8.2 kg). Its double coat consists of a soft, woolly underlayer and a long, dense, luxurious topcoat that may be any color. A probable descendant of the Lhasa apso, the Shih Tzu was sent as a gift by the Tibetan Dali Lamas to the Chinese emperors as early as the 16th cent. In China it was crossed with the Pekingese, both breeds being referred to there as "lion dogs." In its relatively short history in the United States, the Shih Tzu is gaining in popularity as a house pet and watchdog. See dog.