Description of a Pyrenean Mountain Dog.

The Pyrenean Mountain Dog, known as the Great Pyrenees in the United States, is a large breed of dog that was used traditionally for protecting livestock (especially sheep) in pasture.

The Great Pyrenees is readily identifiable by a double dewclaw on each of its hind legs.

It is a very old breed, and has been used for millennia by the Basque people, who inhabit parts of the region in and around the Pyrenees Mountains of southern France. More recently, it served as the official dog of the royal French court (whose prominence began circa the Middle Ages, and lasted until the middle of the nineteenth century). During World War II the dogs were used to haul artillery over the Pyreneean Mountain range to and from Spain and France. They are related to several other large white European Livestock guardian dogs (LGD), including the Italian Maremma Sheepdog, Kuvasz (Hungary), Anatolian Shepherd (Turkey) and Polish Tatra or Polski Owczarek Podhalañski.

Males weigh in at about 100-160 pounds (45-73 kilograms), while females are approximately 85-115 pounds (39-52 kilograms). Their fur is often white with shades of grey or tan around the face, ears and sometimes on the body; these dogs are called "blaireau". Only one in four will have a pure white coat. However, most dogs of this breed, when young, are colored gray with tan spots. They are well known for their back double dewclaws.