Also called Tibetan mastiff, this big dog is a native of the Himalayas. It weighs between 50 and 80 kilos, it has a massive and imposing figure. Its hair is long and very thick, especially on the neck: they form a real dense mane. The name "Do-Khyi" in Tibetan means " door dog ": indeed, it is the ancestral guardian of Tibetan monasteries! This is a very old breed of dog: Aristotle would have described it about 350 years B.C! It is also a very popular breed: the world's most expensive dog was a Do-Khyi, which reached the sum of nearly one and a half million dollars!