Bullmastiff breed | The standard - Bullmastiffs Kennel NightFallKing

The standard of a breed describes the aesthetic and character qualities an ideal dog should possess. They represent above all the points of reference for breeders  and expert dog lovers, making clear the point that this description does not refer to any particular subject.
General aspect: Dog of large size, of a powerful frame, with a balanced and  harmonious form, with a muscular body but not short. Elegant and fairly slim, giving an impression of great strength, but without heaviness, solid and active. Has  the confirmation of a heavy mesomorph  in which the trunk is longer than the height at the withers; the profile of the back and head are in a straight line.
Proportions: The length of the head must be 34% of the height at the withers. The length of the muzzle is equal to 33% of the total length of the head. The length of the trunk is 12% more than the height at the withers. The height at the  chest is equal to or at the most slightly more than half the height at the withers.
Head and skull: The skull must be strong and square from all angles. And very long at the cheek bones and the width often succeeds the length which is equal to 67% of the total length of the head. Seen from the front it is slightly arched,  seen from the side it is generally flat. The nasal angle is at about 110 degrees and the cranial facial angle is of about 140 degrees. The distance from the point of the nose to the stop is about one third  the length of the head. The stop is well defined.  The  brachycephal head, typically molossoide is wide and deep, and the the longitudinal axis of the cranium and the muzzle are perfectly parallel, the skin is wrinkled when the dog is attentive but not at rest. The head is very important in the bullmastiff;  the characteristics which we find in it are elegant and unique to the breed.
Eyes: Are of medium size, dark or hazel, of a square shape, never rounded, and are in the front of the face alone a horizontal axis, the same distance apart as the length of the muzzle and divided by a single furrow. The eyelids are clearly  closed, the inner lids not visible, with an attentive expression.  
Ears: V shaped or folded back, placed very high ( Much higher than the arched zigomatic bone) distanced from each other, tending to make the cranium wider. They should be small and darker than the coat; the tip should be level with the eyes  when he dog is attentive, at rest close to the cheeks. The cartilage of the ears is thin and soft to touch, like soft leather.
Muzzle: The muzzle is short, with a length that corresponds to 33/34% of the total length of the head. The front of the muzzle is square and flat while the sides are parallel. The perimeter of the muzzle corresponds to 60% of the perimeter  of the head. The bite must be even, though a slight undershot is admissible but not desirable. The canines are strong and well defined. In a correct  muzzle the incisor teeth must be lined up at as far as possible at a right angle.
Nose: Black and large, seen from the side it must be on the same line as the nasal channel. The faces of the nose, form a right angle. The nostrils are large and open. The nasal channel presents a straight line.
Upper lips: Seen from the front they appear to form a large upside down " V". From the side they are slightly hanging to cover the jaw, in such a way that the profile of the lower muzzle is outlined by the lips.
Labial commissure: Well defined but not in an exaggerated way. Large  jaws, and thick. The jaw bone from the side is quite curved, defining a well defined chin, elements of fundamental importance to have a large square muzzle.
Neck: Well arched, very muscular, of a medium length (reaching the length of the head), with the nape well defined and a circumference equal to that of the cranium.
Trunk: The back is straight powerful and short, but not too short. The thorax well developed both in height and length and depth, the result being a  well lowered belly. Its size, in a large male, can reach 40% of the height at the withers.  The circumference is more than 33% of the eight at the withers. The belly is full never retracted, the curve of the flanks slightly marked.
Limbs: The height of the front limbs until the elbows is 50% of the height at the withers. In very large examples it can be as much as 51-52%. They are strong and muscular, with well developed legs which show power but not heaviness. Withers  slightly folded. The shoulders are muscular and powerful ; the metacarpus are straight, slim and elastic, and form an angle of 75 degrees. The back legs which are not very long are powerful and muscular. The withers are wide and well defined.  
The feet are very large, with rounded toes and well arched. The nails and pads are dark. Any lightness of colour here constitutes a grave defect.

Gait and movement: The movement denotes power and determination. When walking in a straight line, the front and hind legs must not cross or swing; when trotting the front right leg and the left leg rise at the same time.
Tail:  Is high , wide at the root, and gradually gets smaller. It reaches or surpasses the withers. At rest it is held low, never curved into a ring or held straight up. A thin tail is associated with a weak constitution and poor bone structure.
Coat: The coat is short and thick, of a good texture, lying close to the body. Shiny, dense with a slight undercoat, which becomes thicker in the colder months.
Colour: All the tones of brindle are accepted, fawn and red. It is important that the colour is pure and clean. A small white mark on the chest is permitted, all other marks constitute a defect. The muzzle, the ears and the eye sockets must  be pitch black. The black mask reaches the eyes.  
Weight and size: The English standard, (Approved by the F.C.I.) sets minimum size and weight limits
Male: Height at the withers from 63.5 cm. To 68.5cm.; weight from 50kg. To 59kg.
Female: Height at the withers from 61cm. To 66cm.; weight 41kg. To 50kg.
A good male should be at least 80/82cm and a good female not less than 74/75 cm, with a weight more than those given.
Defects: All the variations reported above are considered defects. In brief, light eyes, rounded ears, irregular teeth, an irregular or rounded back, flat and wide feet, poor withers, a deviant tail, long silky coat, monorchide and criptorchide.