Reproduced with the kind permission of the Kennel Club

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 his 'family', his bravery and courage are legendary, defending them against intruders. He can quickly assess a situation and this, combined with his acute hearing, makes him an excellent housedog. He is very strong, but amenable to kindly discipline.

General Appearance.
Powerful build, symmetrical, showing great strength, but not cumbersome; sound and active.

Characteristics.
Powerful, enduring, active and reliable.

Temperament.
High spirited, alert and faithful.

Head and skull.
Skull large and square, viewed from every angle, fair wrinkle when interested, but not when in repose. Circumference of skull may equal height of dog when measured at top of shoulder; broad and deep with well filled cheeks. Pronounced stop. Muzzle short; distance from tip of nose to stop approx one third of length from tip of nose to centre of occiput, broad under eyes and sustaining nearly the same width to end of nose; blunt and cut of 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.

Eyes.
Dark or hazel, of medium size, set apart the width of the muzzle with furrow between. Light or yellow eyes highly undesirable.

Ears.
V shaped, folded back, 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 are highly undesirable.

Mouth.
Level desired but slightly undershot allowed but not preferred. Canine teeth large and set wide apart, other teeth strong, even and well placed.

Neck.
Well arched, moderate length, very muscular and almost equal to skull in circumference.

Forequarters.
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.

Body.
Back short and straight, giving compact carriage, but not so short as to interfere with movement. Roach and sway backs highly undesirable.

Hindquarters.
Loins wide and muscular with fair depth of flank. Hind legs strong, and muscular; with well developed second thighs, denoting power and activity, not cumbersome. Hocks moderately bent. Cow hocks highly undesirable.

Feet.
Well arched, cat-like, with rounded toes, pads hard. Dark toenails desirable. Splay feet highly undesirable.

Tail.
Set high, strong at root and tapering, reaching to hocks, carried straight or curved, but not hound fashion. Crank tails highly undesirable.

Gait/movement.
Movement indicates power and strength of purpose. When moving straight, neither front nor hind legs should cross or plait, right front and rear left legs rising and falling at the same time.
A firm back line unimpaired by powerful thrust from hind legs denoting a balanced and harmonious movement.

Coat.
Short and hard, weather resistant, lying flat to body. Long silky or woolly coats highly undesirable.

Colour.
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 towards expression.

Size.
Height at shoulder: dogs: 63.5-68.5 CMS (25-27 ins.); bitches 61-66 CMS ( 24-26 ins.).
Weight: dogs 50-90 KGs (110-130 lbs.); bitches 41-50 KGs. (90-110 lbs. ).

Faults.
Any departure from the forgoing points should be considered a fault and the seriousness with which the fault should be regarded should be in exact proportion to the degree of fault.

Note.
Male animals should have two apparently normal testicles fully descended into the scrotum.