We hoped to see some real Tibetan mastiffs while on our trip, but all the "serious" ones were in the mountains with the herds. Only the older and smaller ones were left behind in town (even they are scary - believe me). They are an amazing breed, domesticated for about 6000 years and used to protect shepherds and their yaks. The dogs are extremely fearless, and will attack bears, wolf packs etc. with no hesitation. They are also fiercely loyal, and will only accept food from their owner. For that reason many people guard their building lots in town, by keeping them chained on the property, and feeding them once a day. Recently they have been bought by wealthy Chinese as status symbols and the prices for the "top dogs" are apparently in the $500,000.00 (USD) range! They are also vegetarian... (or so I've been told).

Check out this article:

http://www.timesonline.co.uk/tol/news/world/asia/article2182858.ece