The Bullmastiff, affectionately known as the “Gamekeeper’s Night Dog” is an agile mastiff with a typical molosser appearance.  Developed by crossing the English Mastiff and the Old English Bulldog, the Bullmastiff is a fiercely loyal companion and natural guardian.


A Bullmastiff should appear longer than he is tall, with a short coat, square head, and short muzzle. The coat colour can be fawn, red, or brindle.  They should have a black mask, dark ears, and white is only permissible on the chest.  Ears and tail should be left unaltered, and dewclaws should not be removed.  Males should be 110-130lbs, with females a slightly smaller 100-120lbs.  Breeders are discourages breeding dimension that exceed the maximum weight.  It is common to see overweight Bullmastiffs, as owners become fixated on the numbers on the scale and do not pay close enough attention to the dog’s frame.  Although a large dog breed, even a Bullmastiff should have a waist.  As a breed so prone to disease and joint problems, special care (through proper diet and exercise) should be taken to keep your Bullmastiff light and fit so as not to exacerbate any predisposed genetic conditions.           


Lifespan and Health

The Bullmastiff has an expected lifespan of 8-10 years but is prone to many major health issues.  Some of the health issues include heart disease, hypothyroidism, many forms of cancer, hip and elbow dysplasia, and as with most large breeds; gastric torsion.  They can also be prone to entropian eyelid, which can easily be treated by a vet if it proves problematic.  Similar to other molosser breeds, the Bullmastiff does not do well in the heat and should be kept indoors with air conditioning in hot weather.



In the late 19th century, poaching was becoming so prevalent it began to threaten the lives of the gatekeepers of English estates.  In turn the gatekeepers set to develop a guard dog that would be agile enough to run a poacher down, but large enough to knock them over and hold them without mauling them.  They accomplished this by crossing the large English Mastiff with the more agile Old English Bulldog. Originally the brindle colour was preferred so that they were nearly invisible in the night.  As their popularity increased, estate owners began to utilize them as sentry and the fawn colour became more popular.  They were first recognized as pure by the English Kennel Club in 1924 and are considered to have roughly 60 percent traits of the Mastiff and 40 percent of the Old English Bulldog.



Now bred to retain some of their protective instinct, but with low aggression, Bullmastiffs may seem to be an ideal family dog, but are not recommended for households with infant or young children. They should not be considered for first-time dog owners, or for families with children without previous mastiff experience.  Protective by nature, Bullmastiffs are dominant, and in rescue we often see dominance misinterpreted as aggression.  Special care must be taken to properly socialize your Bullmastiff in a healthy manner, and protective behavior should NEVER be encouraged.  If you are really, and seriously in trouble then your Bullmastiff will know, it should never be allowed when you are not in danger.  Your Bullmastiff should be introduced to as many people and dogs at a young age, in a controlled environment to encourage positive experiences.  A healthy Bullmastiff should be happy and attention seeking of humans, and capable of interacting with canine breeds of all shapes and sizes.  A poorly socialized Bullmastiff will be wary of strangers, protective of territory and personal space, and can be aggressive towards other dogs.  Many Bullmastiffs that come into rescue are under socialized, as they do make for very happy puppies and owners do not feel the need socialize a puppy doesn’t have any problems.  Socializing older Bullmastiffs is a slower, more cautious process but many “problems” that land Bullmastiffs into rescue can be overcome with positive interaction with humans and other canines.  Handling of a Bullmastiff needs to be confident but never abusive.  Your Bullmastiff should always believe that YOU have control of the situation, from introduction to new people to interaction with other dogs.  There will almost certainly be stages where your Bullmastiff will challenge you, anything from fixated staring, to growling, to (in extreme cases) attempts to bite.  Having a consistent set of ground rules, daily exercise and mental stimulation will help curb unwanted behavior, if not eliminate it entirely.  Bullmastiffs are smart, although their stubbornness can be confused with stupidity.  Basic obedience training is always recommended, and although they do not make great agility dogs, they can learn and enjoy the sport, just make sure to keep the jumps low!


If you have your heart set on your own “night dog” keep an eye on Our Adoptables page for any that come into rescue!