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Guarding the Guardian

How to keep a Bullmastiff’s protective instincts under control

As a trainer, I see quite a few Bullmastiffs in my practice, and I have lived with the breed for more than 30 years.  

One problem that keeps coming up – particularly with first-time owners – is that there are situations where the dog is not so friendly anymore, in guard mode, and not listening at all. At the same time, the dog may start to show aggressive behaviors toward other dogs, particularly dogs of the same sex.   These are mostly good owners who did all their homework, talked to breeders and read a lot about the breed. But the literature just doesn’t contain a whole lot about specific Bullmastiff behaviors, and even less about the guard traits and its implications.  

The Bullmastiff is first and foremost a guard dog. The strong guard instinct underlies many breed behaviors.  


Guard breeds need intensive socialization, especially during the period between eight to 14 weeks.


Body blocking is one Bullmastiff behavior that is related to the guard instinct.  When I stand at a counter, the Bullmastiff sits right behind me. If I sit on the sofa, the Bullmastiff sits on my feet, facing away from me to protect me from potential dangers lurking behind the television. Whenever I need to go straight through a room, there is always a Bullmastiff blocking my way! When somebody arrives at the front door, the dog blocks it and turns into an Immovable Object, so that he can inspect the visitors ahead of everybody. By blocking, the dog protects you.  

A Bullmastiff will notice anything new that appears in the house, or even in the neighborhood. It could be a new flag on a pole, or a new trinket in the house, or a pair of new shoes: The dog will notice, alert, investigate, study and think about it. Who knows what the dog really thinks, but it seems he has to make sure there is no danger in new objects.  

Training a Bullmastiff can be a bit of a challenge. The AKC standard describes the Bullmastiff as having a “willingness to please.” This is not quite accurate, as there is a grammatical object missing in the sentence. It should read “willingness to please themselves.” So, the more I make the Bullmastiff think the target behaviors are his own idea, the faster he will learn.  


Protective behavior in a Bullmastiff typically does not surface until the dog reaches adolescence.


Bullmastiffs are great thinkers. When I teach something new, the dog will pick it up just fine, but then he needs to think about it. Some Bullmastiffs will put their own spin on things. My current companion and assistant Gigi (Berbos Brilliant Bridget of Bullmast x Chalfs Mr Bo Jangles by Ch. Brobuds Beryl of Bullmast) will meditate on a new behavior; the next day she often tells me, “I know, and here is a better way.” And often she is correct!  

Bullmastiffs tend to learn behaviors that make sense to them very fast. Part of the guard instinct in Bullmastiffs is a strong sense of what is Mine and Thine. Teaching Bullmastiffs about which objects belong to the dog and which belong to people is easy. They learn greeting rituals, house manners and being polite with no trouble. Teaching “wait,” “stay,” “sit,” “go see,” “who is that?” and “show me what you want” are behaviors the dog does anyhow and are easy to train.  

On the other hand, behaviors like attention heeling and straight sits make little sense to this independent breed. Of course, the Bullmastiff can learn it and do it well – it just takes longer, and the dog may argue with you occasionally. It goes against the dog’s instinct to walk alongside his beloved Person, constantly looking up at his or her face when potential dangers may lurk in front or behind. The dog is more comfortable hanging out somewhere in the vicinity of heel position, scanning the horizon as he walks.  


Exposure to many different people – and animals – expands a young puppy’s understanding of what “normal” is like.


Of course, there is variation in the personalities of different individuals. In some Bullmastiffs, the guard traits are not as noticeable, and in others they are more so. My companion and training assistant Gigi is a little exaggerated. She never misses anything new, however small, and then she inspects it and thinks about it – for the usual 24 hours.  

The guard instinct appears around the time of sexual maturity, sometime between 10 to 18 months of age. Puppies and youngsters typically do not guard. In fact, some owners get a bit worried that their Bullmastiff “loves everybody.” Guarding behaviors tend to appear gradually, and your Bullmastiff starts exhibiting a much deeper bark and more intense behaviors at the front door when people arrive. I have even seen the dog bark for the first time in a deep growly tone, and then look around, like “Did I do that?”  


As goofy and loving as the breed can be, Bullmastiffs consider their primary job to be protecting their humans from anything that is perceived as a threat.


I had a good chuckle when suddenly one dark night 12-month-old Gigi went off barking intensely at the back door for the first time. I realized she had heard something in the back, so I praised her, opened the door and told her “Go see!” She took a good look, then went behind me, like “Eh – you first – I’ll follow.” So the onset is usually gradual, starting with serious alert barks, then more and more confidence.  

Once the dog was domesticated, people developed dogs for different functions. Throughout history, people have selected and prioritized the morphological and behavioral traits that were serviceable for these different functions. Unwanted traits could be suppressed in breeding as well. For example, sled dogs need to be tough and compact, but the demands on endurance limit the size of these dogs. Herding dogs will eye and stalk sheep and goats like wild canids do with prey, but they do not have the consecutive behavior sequence of bite, tear and devour that their ancestors did.  

Guard dogs have conformed to the same general type since time immemorial. Physically, guard dogs need to be large, with a largish head and wide muzzle. The large size with substantial bone provides physical strength; the largish head provides room for bigger and wider jaws and muscles. The more or less brachycephalic skull provides a much greater bite force than other skull types, particularly when combined with strong cheek muscles. Ancient records going back all the way to the Babylonians and the Assyrians, and continuing throughout history, show this type of dog functioning as a guard and war dog. This type of guard dog also has a tendency to bite once and hold.   Behaviorally, guard dogs preserve a very strong sense of territory and territorial defense.  

The guard instinct is basically a reflection of territorial aggression with the function of controlling, protecting and defending an area. These guard traits and behaviors are ancient, deriving from behaviors in the wolf or ancestral proto-dog. For wild canids, the exploration and defense of their territory are a critical survival mechanism. They patrol the territory to gather crucial information about food and intruders. They mark their territory by leaving urine in many spots. The pack will aggressively defend their area, and chase away or even attack intruders.  

The center of the guard dog’s territory is inside the home. Particularly in multi-dog households, some dogs can get possessive about their own sleeping area, but mostly it is the whole home that is protected. A Bullmastiff has an almost compulsive urge to check out visitors by sniffing their shoes. Then the dog lets them in with wagging tail and invitations to “pet me.” However, if there is anything suspicious on the other side of the door, the Bullmastiff will go off into intense guard mode, barking, growling maybe, and trying to push through the door to get out and chase the suspicious one away. These are the occasions when it becomes very tough to control the dog, no matter how well trained he is. It takes special training for getting control of a dog acting aggressively “in the zone.”

The area surrounding the home is also part of the territory. This is the reason for stronger dog aggression close to the home than in strange areas. I suspect the frequent dog aggression in guard breeds is not just a desire to chase away intruders, but also objecting to competition from other dogs.  


Playing tug with a soft toy teaches puppies emotional self-control.


A walk with your dog around the neighborhood becomes a primeval territorial patrol for the dog, and just like his ancestors, your Bullmastiff loves to investigate every piece of garbage and remnants of food on the street, as well as checking who has been there since yesterday and what they have to say. A walk in the ‘hood is one of the great pleasure in your dog’s life. The same old route day after day may get tedious for you, but all the fresh odors make every walk a novel experience for the dog. Many dogs will urinate on walks to mark their territory. In addition, I think that a major function of urinating on the walk is not just “marking,” but also exchange of information between dogs.  

My Gigi selects certain spots for a thorough sniff, then a brief pee, and then an energetic distribution of her odor from urine and paws, scratching with all four paws and a very pleased expression on her face. Reading her “pee” mail, and pee-mail reply sent!  

Bullmastiff conformation follows the general principles above, but the demand on agility makes this breed somewhat smaller than most dogs of this type. This conformation is also what makes the Bullmastiff such a physically strong animal that it is next to impossible for people to control the dog with physical force. Add the strong guard instinct and territoriality, and it becomes obvious that your Bullmastiff needs a high-level behavioral control to function well and not get into trouble in today’s society.  

All large dogs need regular obedience training. As was also noted in the article by Sharron Mischefski in the last issue of Modern Molosser, that is not enough for good control in guard mode. Mischefski got the control in an interesting way, with more advanced obedience training and highly complex obstacle courses where the dog was made to think.  

Here are some other ways to get good control of your guard dog when it is really needed:  

Start in puppyhood. Puppies need socialization during the sensitive period between eight to 14 weeks. Guard breeds need intensive socialization during this period. Some are naturally suspicious of new people. The Bullmastiff has good predisposition for discriminating among people, and this is exactly what needs to be enhanced during this period. As a puppy meets plenty of different kinds of people, he acquires a huge inventory in his memory of what “normal” is like. The mature dog will thus have much improved discrimination and be a lot safer around a large variety of people.  

Play with your puppy. Teach emotional self-control by playing tug with a soft toy. Teach the puppy a whole mouth bite (as opposed to just the front teeth) and hold of the toy. As you tug at the other end, do not shake the toy! Just provide resistance and move it slowly. Then drop your end, have the dog do a “Sit,” grab the toy, and start again. As the puppy plays tug, he will get excited and even a bit aggressive. Great – this is what you want. The puppy needs to learn to control his emotions and sit on command, even when he is very emotional, and playing tug is one way to teach it under controlled circumstances. Bullmastiff puppies love a good tug, they learn to calm down from excitement, then get excited again with more tug, and continue the cycle.  

Teach “Place.” Give the dog a rug or a bed near the front door. Teach him that this is his very own “Place.” Start with throwing treats on it, give bones there, and keep his toys there. Guard breeds are very good at learning about “Mine.” After the dog knows this is his very own “Place”, then add a solid down-stay there. When visitors come to the front door, or whenever the dog gets a little too excited, direct him to his “Place” to stay there. Stationing the dog at his “Place” means you do not exclude him, but you keep the dog under good control.  


The “place” command is especially useful when the doorbell rings and the Bullmastiff’s guard instinct is likely to be ignited.


Consider bite-work. The more mature dog can really profit from skilled bite-work. This is a situation where dogs get very intense and emotional, so it provides an opportunity to teach controls in a realistic setting. And, no, bite-work does not make your dog aggressive. This is not the kind of bite-work that was done with the Gamekeeper’s Night Dog. At that time, the dogs were agitated and trained totally in defense mode to get a seriously aggressive dog under control, and it could be pretty brutal.  


Bite-work is a game of serious tug in prey drive. Contrary to popular belief, it does not make a dog “aggressive.”


Today, bite-work is advanced education. My dogs do bite-work as a game of serious tug in prey drive. This game is physically challenging; the sleeve weighs about 20 pounds, for example. There are lots of rules: instant “out-sit” said in a whisper, correct techniques, countering the trainer’s moves, instant response to trainer and handler. The Schutzhund education also involves advanced obedience. My Bullmastiffs always love this game, and it gives me much better control when they go into guard mode.  



The broad-mouthed guard breeds possess a formidable guard instinct, coupled with a strong tendency to think and act independently. They will take care of intruders. Having a strong guard breed as a family companion is a bit like having a gun in the house. Good thing to have – but handle with care and common sense. Just like you would not leave your gun on the living-room table with ammunition beside it, so you should not let your guard dog just “do his thing.” It is up to you to control your dogs even when they are “in the zone.”  


An awed thank-you to Nicole Reusser and Scott Peterson for the fabulous  photos.




Dr. Mona Lindau-Webb has been in Bullmastiffs since 1980, when she went to “just look” at some Bullmastiff puppies. She has trained and put lots of Obedience titles on her Bullmastiffs, as well as some champion titles. She had the first Agility-titled Bullmastiff (“Tiki”) as well as the first-ever Schutzhund-titled Bullmastiffs (“Tara” and “Albert”). In 1985, she turned from UCLA academics to becoming a professional trainer, now specializing in preventing and treating more serious behavior problems. Her website is www.bestdogtrainer.net.         


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