Bullmastiff Breed Information Guide: Quirks, Pictures, Personality & Facts

Written by: Dr. Katy Nelson

September 25, 2019

Welcome to the BarkPost guide to dog breeds where we belly flop straight into the depths of dog breed origin, evolution, and purpose. Follow along each week as we publish new guides that highlight the strangest, most interesting, and most surprising stuff about these creatures who have been our best buds the last 30,000 years.  

Intro / Overview

(All dogs are individuals, which means any single dog from any breed can be any number of ways, both good and not so good. Keep that in mind as we discuss breed generalities!)

Ah, the friendly Bullmastiff. This gentle giant is perfect for anyone searching for a loyal guard dog. They will be your protectors when you need them but also be more than happy to lounge around on the couch for a lazy afternoon.

This breed belongs to the working group and once socialized — they need lots of puppy classes! — they can get along with the whole family, kids included. Bullmastiffs don’t always like other pups, but if they’re around them enough, they can eventually be pals.

The confident and trustworthy Bullmastiff can appear intimidating, largely in part to them being a stocky mix of a Bull Dog and a Mastiff. That is exactly why these dogs are great watch dogs. They won’t bark at an intruder, though! They’ll track them and alert you to any danger. What good pups!

Also Known As…

The Bullmastiff’s official nickname is The Gamekeeper’s Watch Dog. “


Bullmastiffs were bred back in the 1800s in England to be guard dogs. As the name suggests, they’re a cross between a Mastiff and a Bull Dog. They were created by gamekeepers on sprawling estates to guard the property. Because they’re a cross between two very powerful breeds, the Bullmastiff is naturally strong, fast, and confident. Exactly what you want for a watch dog. However, what sets a Bullmastiff apart from other watch dogs is that they don’t bark! These dogs were bred to be silent trackers.

Bullmastiffs made their way to the United States via John D. Rockefeller, who got one to guard his Tarrytown, NY, estate.


Bullmastiffs are smaller than some Mastiffs, due to being crossed with the smaller Bull Dog breed. They usually stand about 2 feet off the ground and can weigh upwards of 100 pounds. They tend to be large and quite stocky dogs with a broad head.

Weight Range

Male Bullmastiffs can weigh anywhere from 110-130 pounds and females usually weigh between 100 and 120 pounds.


Bullmastiffs are loyal and loving dogs. Because they were bred to be guard dogs, they are naturally loyal to their owners. They also tend to be slightly sedentary, so they love to spend chill time with you. They’re very smart and confident and want to please their owners.

While they tend to get along great with all types of people, they do require socialization early on in life to ensure they maintain their acceptance of strangers and the like.

Intelligence / Trainability

Puppy classes are a must for Bullmastiffs. They are smart and strong-willed, so if not trained properly, they won’t be properly socialized. Once you have your Bullmastiff trained and a proper routine set in place, you should be set for good. They’re definitely a trainable dog, as they do like to make their owners happy.

Best Training Techniques For Bullmastiffs

If you put your Bullmastiff in puppy classes, it’s truly your best bet for training. Let a puppy expert socialize your dog with other pups and other people. The puppy trainer can help you understand best practices for keeping your dog in order at home so you can have an excellent working relationship for their whole life. Your Bullmastiff wants to obey and make you happy, but the first step is puppy training.

Ideal Environment

You have a couple options for housing a Bullmastiff. They aren’t terribly active dogs, so they wouldn’t hate apartment life. They are fine with just going for a short walk every day to get out of the house but are content to lounge on the couch with you inside.

On the flip side, they would also be happy in a house with more space, but if you intent to leave your Bullmastiff out in the yard unattended, make sure you are fenced in. Because this breed is naturally protective and very strong, they can get away and potentially cause harm to anyone who comes to close to their territory if they’re unfamiliar.

If your yard has a full, sturdy fence, though, your Bullmastiff will be happy to hang out out there.

Good For Families And Kids?

Bullmastiffs can get along with anyone once they’ve been socialized. They like people! They’re loyal to their owners, whomever they may be. And yes, they do well with kids when they’re familiar with them. They’re strong pups, though, and sometimes don’t recognize their strength, so you should always be present when they’re interacting with children to make sure everyone is being treated respectfully (of course, this is true of all dogs!).

Average Lifespan

Because of their stature, Bullmastiffs unfortunately have a shorter lifespan. They tend to live between 7 to 9 years.


Bullmastiffs tend to be one of the healthier breeds. They can experience a few common health problems though. Cancer is one that is unfortunately happens to any dog breed. Bullmastiffs that get cancer generally experience lymphosarcoma, osteosarcoma, and hemangiosarcoma. Depending on the severity and overall health of your dog at diagnosis, they can potentially go through surgery to remove the cancer and be fine.

Another health issue your dog might face is hip or elbow dysplasia. For each of these joint issues — more common in large-breed dogs — the ball and socket don’t fit together properly, causing discomfort and issues with movement. Hip dysplasia is hereditary, but AKC-certified purebred Bullmastiffs are tested for it before being bred again, so you shouldn’t have to worry about getting a purebred puppy with hip dysplasia.

Another health issue your dog can face is entropion. This affects their eyes and usually can be detected early in their lives. Entropion is when their eyelids roll in, which irritates the eyeball. If your dog is messing with their eyes constantly, take a closer to look to see if you can see anything amiss. This condition can be corrected with surgery.


Bullmastiffs tend to be pretty chill dogs. While they like to play some, they’re mostly fine with one walk a day and not much more. Don’t expect them to go running with you if you’re an active person, because that’s not something this breed is into. Obviously the activity level will vary from dog to dog, but in general, this breed is pretty chill.

Friendly With…Dogs?

Because of how protective Bullmastiffs often are, it’s not uncommon for them to be reactive toward other dogs. They tend to favor dogs of the opposite sex and do best when socialized with other dogs from a young age.


Bullmastiffs are guard dogs, and as such, don’t always like strangers, who they may view as a threat. Of course, with the proper training and socialization, this can be mitigated, but it’s something to be aware of.

Cat/Other Pets?

If your Bullmastiff is around cats from a young age, chances are they’ll be fine with them. Like with kids and people, it’s all about socializing the dog from puppyhood.

Coat & Grooming

Bullmastiffs have short hair that’s incredibly easy to take care of. Bathe them as needed and take them to a groomer to control the shedding. Otherwise, they’re good to go!

Toys Bullmastiffs Would Like Best

  • Plush toys: Your very calm Bullmastiff will probably like a plush toy that they can bat around and then snuggle with.
  • Tug toys: Your very strong Bullmastiff could give you a run for your money with a Tug Toy. Prepare to lose this game!
  • Super Chewer Toys: Your tough-chewing Bullmastiff will be chewing on these super-durable toys for months!

Recommended Diet Or Supplements

You’ll want to feed your Bullmastiff large-breed specialty dog food right off the bat so they fills out properly. Make sure they’re not exercising right after eating as it can lead to bloat, which is a dangerous stomach issue where the stomach twists. Let your pup rest after eating, so they don’t overexert and hurt themselves.

This breed also does well with joint supplements, since any large breed dog is prone to joint and hip issues. Chat with your vet about what supplements are best for you and when is best to start a regimen.

Glucosamine Supplement For Hip & Joints

These veterinarian-formulated supplements are made with all natural glucosamine, MSM, chondroitin, and hyaluronic acid, all packed into a delicious soft chew. ($32.99.)

Recommended Products

Bullmastiffs, just like any dog, love to take a load off after a long day of…napping or whatever. That’s why they deserve their own bed, especially if they have joint issues.

Orthopedic Ultra Plush Memory Foam Dog Bed

This ultra plush orthopedic dog bed provides support for even the most active of dogs! The combination ergonomic memory foam and gel foam relieves pressure points, and helps ease body aches caused by hip dysplasia, arthritis and other orthopedic issues. ($27.99-64.99.)

Notable Rescues To Find the Bullmastiff of Your Dreams

Notable Instagram Bullmastiffs

Pacino & Ozzie @bullmastiff.pacino

Mosseyoak Sir Duke @mosseyoak_sir_duke

Osa and Knox @osa.knox_thebullmastiffs

Kobe Bear @kobebearbullmastiff

Ol’ Man Smoosh @olmansmoosh

Stella the Bullmastiff @stella_the_bullmastiff

Tut the Bullmastiff @tut.the.bullmastiff

***Looking for a gift to blow your Bullmastiff’s mind? Spoil them with a Super Chewer BarkBox! Every month Super Chewer delivers 2 super-durable toys, designed in-house, 2 full bags of all-natural treats, and 2 (!!) meaty chews. Sign up here and receive a free extra toy every month.

Dog With Super Chewer Viking Sword

Featured image via Bullmastiff.Pacino/Instagram

Want More Big Breed Guides Like This?

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Written by: Dr. Katy Nelson

September 25, 2019