What Is the Difference Between Lhasa Apso & Shih Tzu Dog Breeds?

Both the Lhasa apso and the Shih Tzu are believed to have originated centuries ago in Tibet, though whether they descended from a single Tibetan breed or two separate ones is not clear. In this remote region, the large Tibetan mastiffs stood guard outside Buddhist monasteries and wealthy homes while, inside, smaller sentinel dogs sounded the alarm of any approaching threat. Cherished by Dalai Lamas, these small, shaggy dogs are thought to have made their way to China as tribute gifts to royalty. But it was only under the Dowager Empress Cixi (Tzu Hsi) and her eunuchs that purposeful Shih Tzu breeding began. Meanwhile, Marjorie Wild started a dedicated breeding program for the Lhasa apso in England in 1901 with a number of them brought from India.

The Lhasa apso and the Shih Tzu's size and proportion are quite similar. The Lhasa apso should be about 10 or 11 inches, with most weighing 12 to 18 pounds, while the Shih Tzu's ideal height is from 9 to 10.5 inches at the shoulder and its weight is 9 to 16 pounds. Each breed's length, from its shoulder to the base of its tail, should be slightly longer than its height at the shoulders.

The head and face are where the differences between the two breeds start to become more evident. The muzzle of the Lhasa apso is set lower on its face than the Tzu's and is longer, referenced as "medium length" in the American Kennel Club's standard. The muzzle of the Shih Tzu, on the other hand, is set high on its face, no lower than the bottom eye rim, and is quite short -- no longer than 1 inch from its tip to base. The Lhasa's bite is level or only slightly undershot, but the Shih Tzu's bite is fully undershot. The heads of the two breeds differ as well. The Lhasa's skull is narrow and not domed, while the skull of the Shih Tzu is round, broad and domed.

Both the Lhasa apso and the Shih Tzu have long, dense coats, but while the Lhasa's coat must be straight, the Shih Tzu is allowed to have a slight wave. All colors are acceptable in both breeds. It's very easy to tell the two breeds apart when you spot them at a dog show, however. The hair on a Lhasa's head is simply parted down the middle and left to fall loosely, whereas the Shih Tzu's head hair must be tied up -- often styled in a lavishly full topknot at U.S. dog shows.

This is another area in which the Shih Tzu and the Lhasa apso differ, and many of these variations can be traced back to each breed's roots and purpose. The Shih Tzu's origins as a palace pet and companion instill the breed with an outgoing and friendly demeanor, happy and trusting of everyone it meets. The Lhasa apso is a confident and happy breed, too, but its long history as an indoor watchdog persists in its nature far more than in the Tzu's, making the breed more guarded and wary of strangers. But the Lhasa also has exceptional judgment and restraint. Once it sees its owner is welcoming the newcomer as a friend, the Lhasa will happily do the same.