After discussions between the Bullmastiff Breed Council, the Breed Clubs and the Kennel Club regarding the description of Bullmastiff ears, the Bullmastiff Breed Standard was updated in September 2016 and is reproduced below with the permission of the Kennel Club.
The Bullmastiff comes from the working group of dogs. Over the centuries these dogs were selectively bred to become guards and search and rescue dogs. Arguably, the working group consists of some of the most heroic canines in the world, aiding humans in many walks of life, including the Boxer, Great Dane and St. Bernard. This group consists of the real specialists in their field who excel in their line of work.
The Bullmastiff is a British breed evolved from the Old English Mastiff and the Bulldog. Primarily used as a guard dog and, in olden times, to help the gamekeeper in the apprehension of poachers.
Naturally intelligent and observant, he is easily trained but likes to have a reason for doing things. Highly spirited, he makes a happy companion who is totally reliable both physically and mentally. Devoted to the members of his human family, his bravery and courage in defending them against intruders are legendary. He can quickly assess a situation, and this, combined with his acute hearing, makes him an excellent house-dog. He is very strong, but amenable to kindly discipline.
Powerful build, symmetrical, showing great strength, but not cumbersome; sound and active.
Powerful, enduring, active and reliable.
High-spirited, alert and faithful.
Skull large and square, viewed from every angle, fair wrinkle when interested, but not when in repose. Skull broad and deep with well filled cheeks. Pronounced stop. Muzzle short; distance from tip of nose to stop approximately one-third of length from tip of nose to centre of occiput, broad under eyes and sustaining nearly same width to end of nose; blunt and cut off square, forming right angle with upper line of face, and at same time proportionate with skull. Under-jaw broad to end. Nose broad with widely spreading nostrils; flat, neither pointed nor turned up in profile. Flews not pendulous, never hanging below level of lower jaw.
Dark or hazel, of medium size, set apart the width of muzzle with furrow between. Light or yellow eyes highly undesirable.
V-shaped, folded forward, set on wide and high, level of occiput giving square appearance to skull which is most important. Small and deeper in colour than body. Point of ear level with eye when alert. Rose ears highly undesirable.
Level desired but slightly undershot allowed but not preferred. Canine teeth large and set wide apart, other teeth strong, even and well placed.
Well arched, moderate length, very muscular and almost equal to skull in circumference.
Chest, wide and deep, well let down between forelegs, with deep brisket. Shoulders muscular, sloping and powerful, not overloaded. Forelegs powerful and straight, well boned, set wide apart, presenting a straight front. Pasterns straight and strong.
Back short and straight, giving compact carriage, but not so short as to interfere with activity. Roach and sway backs highly undesirable.
Loins wide and muscular with fair depth of flank. Hindlegs strong and muscular, with well developed second thighs, denoting power and activity, not cumbersome. Hocks moderately bent. Cowhocks highly undesirable.
Well arched, cat-like, with rounded toes, pads hard. Dark toenails desirable. Splayed feet highly undesirable.
Set high, strong at root and tapering, reaching to hocks, carried straight or curved, but not hound-fashion. Crank tails highly undesirable.
Movement indicates power and sense of purpose. When moving straight neither front nor hindlegs should cross or plait, right front and left rear leg rising and falling at same time. A firm backline unimpaired by powerful thrust from hindlegs denoting a balanced and harmonious movement.
Short and hard, weather-resistant, lying flat to body. Long, silky or woolly coats highly undesirable.
Any shade of brindle, fawn or red; colour to be pure and clear. A slight white marking on chest permissible. Other white markings undesirable. Black muzzle essential, toning off towards eyes, with dark markings around eyes contributing to expression.
Height at shoulder: dogs: 64-69 cms (25-27 ins); bitches 61-66 cm (24-26 ins). Weight: dogs: 50-59 kgs (110-130 lbs); bitches: 41-50 kgs (90-110 lbs).
Any departure from the foregoing points should be considered a fault and the seriousness with which the fault should be regarded should be in exact proportion to its degree and its effect upon the health and welfare of the dog.
Male animals should have two apparently normal testicles fully descended into the scrotum.
Here are a selection of the Bullmastiff colours that are seen in the UK show rings (please note that the images have been taken under different lighting conditions and camera settings; reproduction of colours may also vary depending on your screen).