Working Group · Purebred · England's Gamekeeper's Night Dog — a powerful, loyal mastiff-terrier cross bred to silently pin poachers in the dark, combining the Mastiff's size with the Bulldog's tenacity
Watch this video for a quick overview of the Bullmastiff — see the breed in action before diving into the details below.
The Bullmastiff was deliberately created in 19th-century England by English gamekeepers who needed a dog powerful enough to overpower adult poachers, dark-colored enough to work invisibly at night, and controllable enough not to harm those it apprehended. Gamekeepers crossed Mastiffs (for size and power) with Bulldogs (for tenacity, speed, and courage) — eventually settling on approximately 60% Mastiff and 40% Bulldog — to produce the ideal anti-poaching dog. The AKC recognized the Bullmastiff as a purebred in 1933.
Today's Bullmastiff is a calm, dignified, and deeply affectionate family companion that retains its ancestors' protective instincts without their aggression. They are notably low-energy for their size — happy with moderate daily exercise — and are devoted to their families, especially children. However, they are naturally territorial and can be challenging with strangers and other large dogs, requiring early socialization and experienced, confident handling to develop into well-rounded adults.
Real Bullmastiffs — browse photos showcasing their look, size, and personality.
Bullmastiffs are known for being confident and protective. They form deep bonds with their families and thrive on consistent human connection. They strike a good balance — lively enough to enjoy playtime and adventures, but calm enough to settle indoors when the day is done.
Bullmastiffs can be trained with patience and consistency, though they may occasionally test boundaries. They are typically gentle and patient with children, making them a reliable family companion.
Bullmastiffs need regular daily exercise to maintain a healthy weight and an even temperament. They are versatile companions who enjoy active outings but are equally content to relax at home after their needs are met.
Bullmastiffs have a dense double coat built for protection against the elements. They shed year-round with two major blow-out seasons in spring and fall. Regular brushing dramatically reduces the amount of hair around your home and keeps the coat healthy.
Bullmastiffs are moderately trainable and respond well to patient, consistent positive reinforcement. They benefit from clear expectations and a calm, confident trainer who establishes routines early.
Keep sessions short — 10 to 15 minutes — and always end on a success. Enrolling in a puppy or adult obedience class provides structured learning and valuable socialization.
Bullmastiffs are generally large dogs whose size brings certain structural stresses. Responsible breeders screen breeding stock for the most common conditions, significantly reducing risk in puppies from health-tested parents.
A Bullmastiff fits well with families or individuals who can provide moderate daily exercise and consistent companionship. They adapt reasonably well to various living situations as long as their exercise and social needs are met. Not ideal for owners away from home for long hours without a pet care solution in place.
Bullmastiffs need consistent, well-portioned meals matched to their life stage. Overfeeding is one of the biggest health risks for any dog — use these guidelines and adjust based on your dog's activity level and body condition.
These are general guidelines for a giant-breed dog. Always check the feeding instructions on your specific food brand, and adjust based on activity level and body condition score.
Look for dog foods where the first ingredient is a named protein — chicken, beef, salmon, or lamb. Giant-breed formulas are calibrated for their metabolism and nutritional needs.
These common human foods can be toxic — even life-threatening — for dogs. Keep them safely out of reach at all times.
Always bring your Bullmastiff's regular food when boarding. Switching food suddenly can cause digestive upset. Provide the facility your exact feeding schedule and portion sizes.
The upfront cost of a Bullmastiff is just the beginning. Here's a realistic breakdown of what to expect — both to acquire one and to own one for their lifetime.
Beyond the purchase price, owning a Bullmastiff costs between $200–$400 per month on average. Here's where the money goes:
Over a 7–10 year lifespan, a Bullmastiff typically costs between $18,000–$35,000 total — depending on health, lifestyle, and the services you use.
Pet insurance is worth considering for any breed. Buying before your dog turns 1 gives the best rates and fewest pre-existing condition exclusions. Compare 2–3 providers before committing.
Because Bullmastiffs have such wonderful traits, they're a popular choice for intentional mixed breeding. Here are the most common — and most loved — Bullmastiff crosses.
The Lab's friendliness softens the Bullmastiff's territorial nature — a large, loyal, and affectionate family dog that combines the Bullmastiff's protective presence with the Lab's warmth.
Two bully-type British working breeds combine into a powerful, playful, and protective large dog with a clownish streak and deep family devotion.
Two giant breeds combine into an enormous, gentle companion — a very large crossbreed with the Bullmastiff's guarding instincts and the Great Dane's elegant, calm temperament.
Power and protection amplified — a large, confident, and deeply loyal guardian crossbreed requiring experienced ownership and extensive early socialization.
Bullmastiffs are full of surprises. Here are some of the most fascinating, funny, and heartwarming facts about this breed.