There Tibetan mastiff flock guard and the English bred Tibetan mastiff differ enormously in their temperament. The Tibetan guard dog is more aggressive and much more assertive making them hard to train. The English bred Tibetan mastiff is well known for its quiet and relaxed personality, while being a good guard dog and loyal to its family.
Animals & Wildlife Magazine
The Tibetan mastiff was originally bred in the Himalayan mountains to be used to a guard dog for flocks of goat, sheep and cows against hunters and natural hunters such as the Asian black bear and even tigers.