Most of the mastiffs come from cattle farms in the north of the province of León, mainly from Babia and Riaño, where livestock and wolf have always been living together. A good mastín never leaves his flock and always defends him as the best, sometimes he cannot prevent a wolf or a wild dog attacking the cattle, but with his presence he makes the consequences of that attack much smaller. The herdsmen who introduced one or more of these herds in their herds visibly noticed the benefits and went from losing an average of 23 head of cattle a year to only 7. Never attack people only warn of their presence with their barking , is faithful and a great companion.
Although it is almost always related to the mastín with the care of the sheep, we have to know that the mastín takes care of and protects any type of cattle; Cows, horses, goats, etc.

In the region of Babia the mastin is a reference animal, some chosen champions of Spain and runners-up of the World were raised in this region, where also created the Association of Breeders and Friends of the Babia Mastín, in order to continue creating and educating the mastí leones. It is an animal that has protected its flocks for seven centuries, especially the merino sheep, its bark and powerful bark and its size make him a unique dog. It was used a lot during the transhumance, but since the late nineteenth century the transport by rail and road of the herds made this animal only have room where the cattle still continues to have great importance, as are the hills and meadows of Babia. Still there you can see the mastin strolling through the streets of the villages of Babia accompanying and protecting his flock and not showing aggression with the people who cross his path.

In order to have a good watchdog you have to educate him correctly, the choice of the breed is based on a very special characteristics, which the mastín leones meets. In order not to be wrong in the choice, the first thing to do is to observe the parents and of that litter to choose a puppy, without diseases and with an intermediate behavior that shows a certain submission and is not aggressive. In the first months of life the puppy has to live with the herd that will protect in the future, is the fundamental basis of the correct breeding of a guard dog for our herd. One mastín is needed for every 150-200 sheep, with a minimum of two dogs, male and female recommended. This mastín will eventually be a dog with great corpulence and territorial behavior, with a character independent of man and never abandon cattle.

It is a dog with a unique characteristics, one raised in the cross superior to 80 cm in the males and 75 cm in the females, with a weight of approximately 70 Kg, very well proportioned, large and strong head with broad base, wide neck , Strong and muscled with double chin, black palate and powerful chest. The upper lip will cover broadly the lower, small eyes where the lower eyelid leaves part of the conjunctiva, medium ears and falls triangular and flat that should not be amputated. Mastiffs with uniform colors are most appreciated; Yellowish, reddish, reddish and black. Also the layers are evaluated with combined colors, like brindle. All the mucous membranes of the skin must be black. The hind limbs also powerful and muscled, may or may not have spurs and can be simple or double and their amputation is allowed. The anterior limbs are straight and parallel seen from the front.