Aggression to Visitors in the Home (Canine)
Dogs that are unfriendly or aggressive to visitors coming to the home are usually inadequately socialized and therefore uncomfortable around strangers. These dogs may also suffer from a genetic makeup that predisposes them to fear strangers (novelty). Implementation of a behavior modification program can sometimes improve the behavior of dogs exhibiting aggression to strangers in the home. The program consists of teaching the dog appropriate behavior to perform when guests come to the home and conditioning the dog to enjoy the company of strangers.
Common names:Territorial aggression, Door aggression, Barrier aggression, Aggression to people, Protective, Suspicious of people, Guarding.
Scientific names:Territorial aggression, Barrier aggression, Protective aggression.
Dogs that are unfriendly and aggressive to visitors coming to the home are most likely to develop this behavior problem as they reach maturity, between 6 and 18 months of age. Sex and reproductive status are not typically factors bearing on this behavior. There may be a slight overrepresentation of the working and guarding breeds, but a dog of any breed can easily develop this behavior if not adequately socialized with people.
The incidence of this behavior problem in the pet dog population is unknown, but anecdotal reports from trainers and behaviorists suggest that it is quite common.
There is no predilection for this behavior based on geography.
Clinical signs (primary, most to least frequent, scientific term, synonyms)
Aggressive behavior (lunging, charging, jumping up on, growling, snapping, biting), Fearful behavior (tail tucked, ears back, retreating, hiding behind pet parent, growling, snapping or biting if reached for, snapping or biting when visitor turns his or her back to the dog).
Clinical signs (secondary, most to least frequent, scientific term, synonyms)
Excessive barking, Patrolling windows and entrances/exits.
Causes (scientific, common term)
Inadequate socialization, Genetic predisposition toward neophobia (fear of novelty), Genetic predisposition toward protective behavior.
Organ system affected (most to least affected)
No organ systems are affected.
Trauma-induced fear of strangers, Hyper-arousal with comings and goings at entrances/exits.
Some dogs are unfriendly or even dangerous to visitors entering the home. They might charge at the stranger, barking, growling, snapping or biting. Alternatively, they might hide behind the pet parent and growl, possibly biting should the stranger reach for or turn his or her back on the dog. Dogs exhibiting these patterns of behavior are usually motivated by a fear of strangers. They may not appear frightened, but underneath the tough exterior, these dogs are typically nervous around new things, particularly unfamiliar people. The problem often stems from inadequate socialization.
Dogs undergo a period in their development, roughly between 6 and 16 weeks, when they are particularly accepting of new experiences. If they have pleasant encounters with numerous strangers during this time, they are likely to continue to enjoy meeting new people.
If they lack this exposure as youngsters, as adults they will tend to be wary and suspicious of strangers. Some manifest this discomfort as anxiety and suspicion; others behave aggressively toward strangers, particularly in the home, where the dog is more confident on his own turf. The onset of aggressive behavior often coincides with maturity, somewhere between 6 and 18 months of age.
Cases of door aggression in which the dog does not bite can usually be improved by teaching the dog to perform specific behaviors when people come to the home. The dog is taught, with reward-based training (treat, praise), to go and stay in an area close but not adjacent to the entranceway.
Once the dog performs this behavior reliably, the pet parent repeatedly pretends that a guest is at the door and practices sending the dog to the area. Once there, the dog is rewarded with treats tossed by the parent from the entranceway. When the dog is consistently able to stay in place, the pet parent recruits helpers the dog likes, such as family members or close friends. Helpers arrive at predetermined times, and the pet parent works with the dog to practice staying in the area. The helper tosses treats to reward the dog. The dog then associates the presence of guests in the home with tasty treats.
Conduct 10 to 20 mock visits with the same helper over an hour or so. Repeat these mock visits with different helpers numerous times over several months. It is a good idea to barricade the dog behind a fence or baby gate the first time unfamiliar guests come to the home, in case the dog fails to stay in the area.
Serious cases of dogs that pose a danger to people should be handled by a certified applied animal behaviorist, a board-certified veterinary behaviorist or a certified pet dog trainer experienced with aggression. The professional will determine if it is safe to implement behavior modification and, if so, recommend necessary precautions. We advise frequent supervision by the professional.
The first step in treating aggression to visitors is to ensure safety. If the dog is not dangerous, pet parents can attempt behavior modification. Dogs that are potential threats to people must not come in contact with strangers. Consult with a behaviorist or experienced trainer. Regardless of the severity of the problem, improvement requires time, patience and dedication on the part of the pet parent.
With dedicated attention, dogs exhibiting aggression to visitors can improve significantly.
McConnell, P. The cautious canine: how to help dogs conquer their fears. Dog's Best Friend, Ltd., 1998.
Hetts, S. Pet behaviorprotocols: what to say, what to do, when to refer. Lakewood CO: AAHA Press, 1999.
Pamela Reid, Ph.D.
Certified Applied Animal Behaviorist
Steven Hansen, DVM, MS, MBA, DABVT, DABT
© 2007. The American Society for the Prevention of Cruelty to Animals (ASPCA)