The Tibetan Mastiff is a large Tibetan dog breed (Canis lupus familiaris) (Tibetan: དོ་ཁྱི, Chinese: 藏獒; Pinyin: Zàng áo). Originating with the nomadic cultures of Tibet, China, India, Mongolia and Nepal, it is used by local tribes of Tibetans to protect sheep from wolves, leopards, bears, large mustelids, and tigers.
The Tibetan Mastiff known as Drog-Khyi (འབྲོག་ཁྱི) in Tibetan, which means “nomad dog”, (“dog which may be tied”, “dog which may be kept”), reflects its use as a guardian of herds, flocks, tents, villages, monasteries, and palaces, much as the old English ban-dog (also meaning tied dog) was a dog tied outside the home as a guardian. However, in nomad camps and in villages, the Drog-Khyi is traditionally allowed to run loose at night. This dog is known for its loyalty, it has been used as nomad dog by for thousands of years.
The guardian type from which the modern Tibetan Mastiff breed has been derived was known across the ancient world by many names. Bhote Kukur in Nepali as bhote means someone from Tibet and kukur means dog. The Chinese name for the breed is 藏獒 (Chinese: Zàng áo; Cantonese: Tzong ngou), meaning “Tibetan Mastiff-dog”. In Mongolia, it is called банхар (bankhar).
The name Tibetan Mastiff is a misnomer; the Tibetan Mastiff itself is not a true Mastiff. The term “mastiff” was used by the Europeans who first came to Tibet because it was used to refer to nearly all large dog breeds in the West. Early Western visitors to Tibet misnamed several of its breeds: The “Tibetan Terrier” is not a terrier and the “Tibetan Spaniel” is not a spaniel. A better name for the dog might be Tibetan mountain dog or, to encompass the landrace breed throughout its range, Himalayan mountain dog. [Source: Wikipedia]
Here are some videos from Dogumentary TV about the Tibetan Mastiff. (4 Feb 2017)