The Pyrenean Mastiff is a large breed of Livestock Guardian Dog (LGD) native to the Pyrenees Mountains of Spain. Its origins can be traced back to around 3,000 years ago. It was primarily used for guarding flocks and protecting them from wolves, bears, and thieves. The breed nearly went extinct in the mid-20th century due to a decrease in predators and changes in livestock management practices, but a concerted effort in the 1970s by a group of enthusiasts revived the breed. The breed is relatively rare outside of its native Spain.
Currently, there are no known genetic conditions tightly associated with the very rare Pyrenean Mastiff breed. These deep-chested dogs are susceptible to bloat, also known as gastric dilation volvulus (GDV). This is a life-threatening condition that can come on suddenly, so it’s important to know the warning signs and get an affected dog immediate veterinary care. Genetic testing is recommended, including for the following conditions that affect many other breeds: hyperuricosoria, degenerative myelopathy, and progressive rod-cone degeneration.
Pyrenean Mastiffs are known for their gentle and calm demeanor. Despite their large size, they are often described as 'gentle giants.' They are typically good-natured, quiet, and docile. They are loyal and protective of their family, and tend to be reserved with strangers but are not typically aggressive. As a flock guardian breed, they can be independent and somewhat aloof. Early socialization is essential to ensure they grow up to be well-rounded dogs. These dogs also drool a lot, so be prepared whenever they're eating, drinking, or exposed to the heat!
Pyrenean Mastiffs can weigh anywhere from 120 to over 200 pounds, making them one of the largest dog breeds in the world.
Despite their size and protective nature, they're known for being exceptionally gentle with children and smaller animals.
In their native region, they participate in a traditional festival known as "El Día del Mastín," or "Day of the Mastiff," where they're celebrated and paraded through the streets.
https://vgl.ucdavis.edu/breed/pyrenean-mastiff
https://www.fci.be/en/nomenclature/PYRENEAN-MASTIFF-92.html
https://www.ukcdogs.com/pyrenean-mastiff
https://www.akc.org/dog-breeds/pyrenean-mastiff/