The Patou is widely used throughout France as a livestock guardian, particularly in the French Alps and the Pyrenees, protecting flocks from predation by wolves and bears.

[note 1] It is sometimes claimed that its forebears – and those of the Pyrenean Mastiff – were white livestock guardian dogs brought to the area from Asia in Roman times, and thus that it is related to Maremmano-Abruzzese Sheepdog of Italy and the Kuvasz of Hungary.

[2][3] Local shepherds sold pups to eager tourists and some of these found their way to Britain, where several were registered with The Kennel Club at the beginning of the century; British interest in such a large breed declined during the First World War.

[2][5][7] In 1946 the Real Sociedad Canina de España recognised the large white livestock guardian dogs on the western or Spanish side of the Pyrenees as the Mastín del Pirineo or Pyrenean Mastiff, with a slightly different breed standard.

[9] In the early 1930s the Pyrenean Mountain Dog was exported to North America, where it is known as the Great Pyrenees and became a favourite in the show ring in both Canada and the United States.

[2] In 2011, to combat the perceived deterioration of show lines of the dog, the British Pyrenean Mountain Dog breed club released a brochure with instructions to show judges not to reward glamorous, heavy-bodied, short-muzzled examples of the breed over lean and muscular examples with weatherproof coats, capable of performing their original role in high mountainous regions.

[3] They were also used to smuggle contraband between France and Spain, carrying packs over the Pyrenees on routes impassable to humans to avoid detection by customs officials.

[12] In the early 1990s Italian wolves began to cross from Italy into France, where they have become established in approximately one third of its continental territories, particularly in the French Alps and Provence, but also throughout the Massif Central.

[16] To assist the shepherds, government funding was provided to implement the same protection measures as those employed for wolves, and Pyrenean Mountain Dogs were given to farmers in the Pyrenees to guard flocks from predators.

[13][19] Several factors influenced the move to integrate livestock guardian dogs into farming operations, including federal restrictions on the use of poisons to control predator numbers.