Molosser dog of medium size, well balanced, of straight profile, with a black mask.
Rustic and well proportioned. It is mesomorphic; the body is longer than the height to the withers.
Females accentuate this characteristic being slightly longer.

Temperament/behaviour:

Their appearance is calm. Attentive gaze. Especially equipped for the function of guarding and traditionally used for the handling and driving of cattle.
Their temperament is balanced and of great self-security.
Serious and profound bark. He is gentle and noble with his family, with great affection to his owner, and suspicious with strangers.
Expression is confident, noble and a little distant. When alert his attitude is very firm and the gaze is watchful.

Head:

Is massive, brachycephalic, of solid appearance, and covered with loose hanging skin.
Its shape is a somewhat lengthened cube.
The proportions of cranium-muzzle are 60%-40%. The width of the cranium is 3/5 of the total longitude of the head.

Cranium:

Lightly convex in anteroposterior and transversal directions, although the frontal bone is flatten to the plane. Zygomatic arch very pronounced, with well developed temporal and mastoid muscles, but without being pronounced. The occipital crest is unappreciable.

Nasofrontal depression (stop):

Defined, but not abrupt. The middle furrow between the frontal sinuses is marked and occupies approx imately two thirds of the cranium. The craniofacial lines are parallel or lightly convergent.

Facial region:
-Muzzle:

Shorter than the cranium. Normally 40% of the total head. The width is 2/3 of the cranium. It is of very wide base and diminishes slightly toward the nose. The nasal line is flat, of straight profile and without ridges.

-Nose:

Wide, strongly pigmented in black. It is inserted on the same line as the nasal cana. The front is set slightly behind the front of the lips. The nostrils are large, appropriate for easy breeding.

-Lips:

The upper lips hang, but without excess and when viewed from the front form an inverted "V" where they join.
The interior lips are dark.

Manidible/teeth:

Scissor bite. Level bite is accepted although not desirable due to the tooth where that it causes. Slight prognathism permitted. The canines show wide transverse distance. The teeth are white, with a strong base of implantation with large molars, small incisors and well-developed and correct fitting canines.

Eyes:

Slightly oval, medium to large size, well separated brevilineal, neither sunken nor bulging. They are well pigmented in black and tight, never drooping. The color fluctuates between medium to dark chestnut, in accordance with the color of the coat. Never light.

Ears:

Of medium size, well separated, with short and fine hair, they drop effortlessly to both sides of the head. If they are folded, they are rose shaped, close fitting to the head. The base is at a point slighter higher than the eye line. Ears set very high and joint are atypical and excessively crowed the top of the cranium. If cropped they are erect.

Neck:

Somewhat shorter than the total length of the head. The lower portion presents loose skin that contributes to the formation of a slight dewlap. It is solid, straight, cylindrical and very muscular.

Body:

Straight lined, wide, deep, the Length is 18-20% longer than the height at the withers, this being more accentuated in females. The flanks are not very marked.

Topline:

Straight, without deformities, supported by well developed, but not very visible musculature. It ascends slightly from withers to the croup. Never saddled nor roached.

Croup:

Medium, wide and rounded. It should not be long, because it would limit movement.
Females normally wider.

Chest:

With great width, pectoral muscles very marked. The depth should arrive to a minimum at the elbow, from the profile and from front. The thoracic perimeter will be normally equal to the height at the withers plus 45%s. Ribs very arched.

Lower line:

Lightly tucked, never descending.

Tail:

Thick base, narrowing until the tip and not surpassing the hock. Insertion medium. In action it rises in shape of a saber, without coiling or pointing toward the back. It in rest hangs straight with a slight curve in the tip.

Extremities:

Front limbs:

Shoulders: With good inclination.
Forelimbs: Well angulated, oblique and perfectly composed, straight, of wide bones and with good musculature.
Elbows: They should not be affixed to the chest or pointing outward. The distance of the elbow to the ground normally represents 50% of the total height in the males and somewhat less in the females.
Metacarpals: Very solid and slightly inclined.
Front feet: Cat foot with rounded toes, not very close together. The pads are well developed and black. The nails are dark, with is undesirable, although they can appear according to the coat.

Hind limbs:

Strong and parallel, without deviations.

Thigh: Long and very muscular. The angulation is not pronounced, but without being scarce.
Hocks: Always low.
Rear Feet: Slightly longer than the front and of the same characteristics.

Movement:
The movement should be agile, elastic and cover a lot of ground. Long steps. The carriage of the tail is low and barely rises above the dorsal line. At attention, the position of the head and the tail is raised.

Skin:
Thick and elastic. Loose in and around the neck. When alert it forms several symmetrical wrinkles in the middle furrow between the front sinuses like axis in the head.

Coat:

-hair:

Short, rustic, very flat, without undercoat (at times might be found, in the neck and buttocks) and with a certain harshness to the touch. Is very short and fine in the ears, slightly longer in the withers and crest of the buttocks.

-color:

Brindle all ranges, from dark very warm tones to the very light gray or blond. Fawn to sandy in all ranges. Marking can appear on the crest, at the base of the neck or throat, on front and rear toes, it is desirable that it is reduced as much as possible.
Mask always black and should not surpasses the height of the eyes.

Size and weight:

-height to the withers:

Males: 60 to 65 cm. (23.5-25.5 in.) Females: 56 to 61 cm. (22-24 in.)
In the case of very typical specimens, a 1 cm deviation from the set maximum and minimum will be allowed.

-minimum weights:

Males: 50 kg (110 lbs) Females: 40 kg (88 lbs)

Faults:

And deviation of the afore mentioned is considered a fault and the seriousness of it is considered to the degree of deviation from the standard.

-Slight faults:

-Excessive wrinkles in the craniofacial region, which does not spoil the expression.
-Pincer bite.

-Serious faults:

-Head that doesn't complete the established proportion.
-Craniofacial lines very convergent (excessive stop, very marked).

-Very serious faults:

-Saddled or roached top line.
-Absence of any tooth (except the P.1).
Eyes light (yellow). Eyes very close together or oblique. Protruding or sunken.

-Eliminatory faults:

-Total absence of mask.
- Undesirable white markings.
- Overbite
- Blue eyes or with different colours.