The Tibetan Mastiff is an ancient breed and type of large Tibetan dog breeds originating with nomadic cultures of Tibet, China, Nepal, and India. The breed is widely used by local tribes of Himachal Pradesh, China, Nepal and Tibet to protect their sheep from leopards. ~wikipedia
And it seems is now the most expensive dog breed in the world!
The Catahoula Cur is an American dog breed named after Catahoula Parish, in the state of Louisiana, in the United States. After becoming the state dog of Louisiana in 1979, its name was officially changed to Louisiana Catahoula Leopard Dog. The breed is sometimes referred to as the “Catahoula Hound” or “Catahoula Leopard Hound”, although it is not a true hound, but a cur. It is also called the “Catahoula Hog Dog”, reflecting its traditional use in hunting wild boar. ~wikipedia
#3 – Thai Ridgeback
The Thai Ridgeback is an ancient landrace of dog, recently established also as a standardized breed. The breed was formerly unknown outside of Thailand, but is gaining notice in the Western world. They are also known as a Mah Thai Lang Ahn. The Thai Ridgeback is one of only three breeds that has a ridge of hair that runs along its back in the opposite direction to the rest of the coat. ~wikipedia