In the 1800s, bullmastiffs were bred by English gamekeepers to assist them as well as English wardens in guarding estates. Consequently, the bullmastiff came to be known as the Gamekeeper’s Night Dog. This breed of dog barks less than other breeds, but barks on alarm. It is massive and powerful and is calm and quiet indoors. Because of their instinctively aggressive nature, bullmastiffs do not always get along with other dogs. Male bullmastiffs in particular do not like other male bullmastiffs while occasionally female bullmastiffs have been known to fight with other female bullmastiffs as well. This may be because of a dominance issue. Whatever the reason, bullmastiff aggression can be a problem especially because of the dog’s large size.
Because of selective breeding, bullmastiff aggression has been minimized and reduced in bullmastiffs significantly, but the trait remains. Because of this, bullmastiffs are capable of inflicting serious harm. The two most common types of aggression are aggression towards strangers and aggression geared towards family members. Aggression towards strangers can be seen if the bullmastiff is either jumpy or alert or if the bullmastiff is very still and staring hard at the object of his suspicion. This happens to bullmastiffs that never had the chance to get used to other people. Socialization could prevent stranger aggression if the dog has been exposed to these things since puppyhood. Socialization is an ongoing thing throughout the life of the puppy and the bullmastiff as an adult. The more the type of people and animal the dog meets, the more at ease it will be around strangers in general. Aggression towards family members can be seen, meanwhile, if the bullmastiff is acting aggressively towards members of the family because of resource guarding or overly possessive behavior of the bullmastiff itself. This is so because all bullmastiffs by nature can be possessive from time to time. Bullmastiffs are pack animals, and they are used to hierarchies of position in relation to other animals. To the bullmastiff, the family is no different from a pack. If the dog perceives itself as higher in rank than the other members of the family, it is going to start acting aggressively. This is because dominance and aggression are the rights of a superior-ranked animal.
Bullmastiff aggression can be treated by consistent, frequent obedience work. The owner should make the dog feel who’s the boss by rewarding it either with treats or praises for following a command or by isolating it or not talking to it if it misbehaves. It is important to remember that if anything goes wrong in the breeding, training and handling of bullmastiffs, the dog is capable of injuring or killing other animals and even people. Combating bullmastiff aggression while the dog is still a puppy is important in order for the dog to develop good habits while growing up. Bullmastiffs may be instinctively aggressive by nature, but they are docile, obedient animals ready to do the bidding of their owner if only they were trained to do so.