It originates in the historical province of Trás-os-Montes e Alto Douro in north-eastern Portugal, and is a rare breed confined mostly to this area.

[1][2][4] In ancient times, this molossus dog was found in the high regions of Portugal, in particular in Trás-os-Montes e Alto Douro Province.

The breed is used to improve pastoralism by developing it as a livestock guardian dog, particularly against Iberian wolf attacks, that are always prolific in the area.

[1][2] In the mountains of Portugal, which are characterized by steep fields of pastures and difficult road access, this breed has adapted to the conditions of the region[2] (i.e., may be classified as a landrace), and to the types of cattle, sheep, and goats that have traditionally grazed in these areas.

Since their return in 2008 through 2014, Oregon Department of Fish and Wildlife documented "86 fatal wolf attacks on livestock.

[7] The breed has a short to medium coat with a dense undercoat, well adapted to the warm dry climate of the region.

[2] Generally the coat is white, with large patches of black, yellow, fawn, brindle or 'wolf grey'.

[2] They are first and foremost working livestock guardian dogs, and their development and temperament should be understood and appreciated in that context.

[2][9] They are high energy — fit, active, vigorous defenders of the flock, and well adapted to fending off wild boar, foxes, and wolves, which are the prevalent predators in the area.

"[1][9] "This dog is an athlete of all terrain able to make many miles along rugged landscapes, protecting both day and night his herd of possible threats.

[2] Like most livestock guardian dogs, they bond with the flock; they are independent thinkers; and they must be trained to respond to their master's voice.