Breed At A Glance


Affectionate, protective, docile unless provoked

Life Expectancy
9-10 years

Average Height
Males 25-27 inches; Females 24-26 inches

Average Weight
Males 110-133 lbs; Females 100-120 lbs

Coat Color
Brindle, fawn, or red, with black markings on the head

Coat Length/Texture
Short and slightly rough

Shedding Propensity

General Temperament

The Bullmastiff is a calm and quiet breed, very loving and affectionate to those they know. Loyal and devoted, they have a strong protective instinct and will defend their family against anything they see as threatening. Although they have a strong protective instinct, they will not usually attack to defend; they are much more likely to tackle and pin down an intruder than to bite him/her. Bullmastiffs are not normally aggressive, and in fact are quite patient and docile in their everyday lives. They thrive on loving affection from their human family, and need to live inside the house as opposed to outdoors in a kennel.

Bullmastiff puppies can be rambunctious and uncoordinated, which can put toddlers in danger of being knocked over or stepped on. But as adults, their easy-going and tolerant nature makes them excellent companions for children, and children should be taught not to take advantage of this. Bullmastiffs may or may not get along with other dogs and household pets, depending on their individual personality and level of socialization.

Early obedience training is essential with this breed, as Bullmastiffs grow into massive and strong adults. They require an owner who is capable of establishing and maintaining dominance otherwise they can become unruly and uncontrollable. They can be happy in an apartment, but this breed tends to be lazy as they age, so in all cases be sure to provide regular structured exercise.

Breed History

The Bullmastiff was developed in England around the mid-1800’s. Gamekeepers at game reserves and large estates at that time sought a dog that could help provide protection from poachers. The English Mastiff was crossed with the Old English Bulldog, producing a large, strong and fearless dog that would attack on command. The brindle coloring was preferred by gamekeepers for guarding at night, giving way to the nickname “Night Dog.”

The English Kennel Club recognized the Bullmastiff as a pure breed in 1924, and was accepted into the American Kennel Club in 1933.

Body Structure and Composition

Other than it’s sheer size and stature, the most noticeable physical characteristic on the Bullmastiff is it’s square-looking head and short, square muzzle. The skin is loose on the face and the lips and cheeks are quite pendulous. The ears are set high on the head and fold forward at all times. The neck is thick and muscular, approximately the same circumference as the skull. The body is compact for it’s size, with a deep and wide chest, short back, and a level topline. The tail is strong at the base and tapers reaching the hock.

Medical Information

Bullmastiffs suffer from many of the same medical issues that plague other large breed dogs, the most significant of which is Hip or Elbow Dysplasia. This condition occurs when the head of the bone no longer fits in the cup provided by the socket, causing arthritis-like symptoms and lameness. Another condition that significantly affects this breed is bloat, otherwise known as Gastric Dilation Volvulus (GDV). Excess gas trapped in the dog’s stomach causes “bloat,” and twisting of the stomach (volvulus or “torsion”) causes or is caused by said excess gas. GDV is an emergency condition requiring immediate veterinary treatment. Feeding the dog two to three small meals per day (as opposed to one large meal) and avoiding exercise immediately after eating may help prevent this condition.

This breed is also prone to various eye disorders, including Entropion (inward-turning eyelashes) and Distichiasis (extra eyelashes along the margin of the eyelid). Both of these malformations can result in corneal ulcers and inflammation. Progressive Retinal Atrophy (PRA) can occur in some lines, resulting in degradation of the retina leading to blindness.

The Bullmastiff is surprisingly sensitive to anesthesia: they do not tolerate the normal dosage determined by weight. Incorrect dosage can result in death. It’s important to locate a veterinarian who is familiar with this breed before any surgical procedures.

Bullmastiffs also have an unusually high incidence of cancer, the reasons for which are largely unknown.

The coat of a Bullmastiff does not shed much and a simple occasional brushing is all that’s required. Don’t wash this breed too often as you risk removing the essential oils from the skin. Be careful not to overfeed this breed, as they are prone to obesity. Before purchasing a Bullmastiff, potential owners should be aware that this breed tends to snore and drool.

Anecdotal Information

Singers Robbie Williams and Christina Aguilera each have a Bullmastiff.

The Bullmastiff has been featured in many Hollywood films, including RockyLicense to WedSee Spot RunHound of the BaskervillesDickie Roberts, and Little Black Book.

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