It is a breed of Spain , belongs to the Aragonese Pyrenees . It is recognized by the FCI and ROCE .

They are dogs that have always been used to guard herds and farms , especially cattle , due to their large size and strength since I defend their masters from attack either bears, wolves and thieves. Although used to that, they are very caroñosos , gentle and noble dogs, also show high intelligence and easy training. With other dogs behave well unless you bother them, as with strangers is very brave and fierce .

They are of great size of the largest in the world ranging from its minimum measures 77 cm . for males and 72 cm . for females. Their coat is abundant , thick , dense and rather long . They are usually white with prominent mask, although there are specimens with spots of the same color as the mask , it is desirable that the spots are well defined .

It is an almost extinct race because to find a popular standard have made many mixtures.