Dogo Argentino

Dog

The Argentine Mastiff (also known as the Dogo Argentino) is a large, white, muscular dog that was developed in Argentina primarily for the purpose of big-game hunting, including wild boar and puma; the breeder, Antonio Nores Martinez, also wanted a dog that would exhibit steadfast bravery and willingly protect its human companion to the death.

http://en.wikipedia.org/wiki/Argentine_Dogo