5 min read


Why Dogs Bite Strangers



5 min read


Why Dogs Bite Strangers




Does your pet bark when a stranger approaches him or your home? It is estimated that 60-70 percent of dogs will bark threateningly at strangers and act hostile towards them. This is common behavior and often why people get a dog in the first place. Nothing says ‘intruder beware’ like the menacing bark of a dog. As a pet owner, we would never want to think our beloved dog would harm someone. But, it does happen. According to the CDC “About 4.5 million Americans receive dog bites each year, many of which require immediate medical attention.” While it is natural to bark at strangers, biting them is a sign of a larger problem. It is important to discern if your dog is going on instinct or is becoming aggressive. You can help your dog learn to accept strangers and to be protective without becoming aggressive. Let him warn strangers to beware, but make sure he is not put in the position to harm someone who is really a friend and well doer.

The Root of the Behavior

It is completely natural for your dog to protect you or his territory. In fact, there are some breeds for which it is seemingly inherent such as Mastiffs, who are bred for guarding, as well as some breeds in the terrier and herding families. Dogs have a sense of protection and ownership over their home, their family and their belongings. They do not know what this unknown person may do, but they do know they need to protect what is theirs. Barking is their way of saying ‘this is mine, get your own, go away.’ Typically, you can train your dog how to accept strangers through socialization and behavior management techniques.

Dogs can become aggressive if they are afraid. Their fear comes from the unfamiliar or when they are challenged. When they are aggressive they can bite. As a stranger approaches and your dog is barking, watch his body language. Is his body stiff, is he growling with bared teeth, and is his hair is standing on end? He is most likely being aggressive. An aggressive dog may feel he has no recourse but to bite the stranger to get him to leave. His aggression may be from anxiety or fear and it will take a bit more work to help him. If your dog is trying to or is actively biting strangers from aggression it is important to visit a veterinarian to rule out any medical problems that could be causing the aggression. It is also recommended you seek assistance from a dog trainer who has extensive training and education in working with a dog with aggressive behavior. It is important to find the cause of the aggression and train the dog to be gentle before his biting of strangers causes a serious wound.

Often, dogs are fearful of strangers because their owner have inadvertently rewarded them for being overprotective in the past. Other dogs have past experiences with strangers that have left them fearful. Some dogs will only be aggressive towards and try to bite certain types of people. They may just fear people who walk with a cane, the mailman, or the veterinarian. Often you can just avoid those groups of people, but it is best to teach your dog how to get over his fear through desensitization and counterconditioning. 

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Encouraging the Behavior

While you do want your dog to offer protection and ward off any potential intruders, you do not want him to harm innocent strangers visiting your home or area. You can help your dog deal with strangers to decrease the chances that he will be anxious or afraid and become aggressive. These tools are most effective when used early on, so do not hope that the fear will pass with age but rather address it immediately. Your ultimate goal is to decrease your dog’s reaction to the stranger to enable him to be around them and remain at peace. To desensitize him, he must be exposed to strangers repeatedly in a controlled environment such as your home.

When strangers come to your home, greet them at the door with your dog on a leash. Through counterconditioning, you can reward him with praise or treats when he behaves by sitting or remaining calm. You can even have multiple strangers approach your home over a short course of time to really hone in on the desired behavior. If you first touch the stranger and then let the dog smell your hand he can get a sense of the stranger and that can help ease his fears. While strangers are in your home, you can set up tethering stations in your home for the dog and allow the visitors to enter those areas and reward the dog for behaving.

If your dog is particularly agitated, you can set up a barrier such as a baby gate, where the dog can see you with the stranger but cannot access him. Ask your visitors to approach the dog from a sideways stance and not make eye contact with the dog until he seems calm. They should keep calm and appear disinterested in the dog, with their eyes focused on the ground away from your pet. When the dog calms, the guest can command the dog to sit and offer a treat when he performs the desired behavior. The more you desensitize your dog to being around strangers, the better off everyone will be.

Other Solutions and Considerations

Should your pooch wound a stranger it is important to take medical precautions. If he breaks, punctures, or tears the skin, your guest can be at risk for infection. Wash the wound immediately, apply an antibacterial ointment, and cover it with a sterile bandage. Call a doctor if there is swelling, redness or pus; if the bite is deep or large or may need stitches; the wound is on your guest’s head, face, hands or neck, or if the bleeding does not stop after a few minutes. If your guest has not had a recent tetanus shot or the dog’s vaccinations are not up to date they should also seek medical attention.


Dogs are not unkind animals, but they definitely have their own set of social rules and approaches to life. If a dog has bitten a stranger, he was most likely being aggressive because he was anxious or afraid. This could stem from being rewarded for being protective in the past, from negative past experiences, or from a need to protect what is his. To avoid having your dog become aggressive and possibly bite strangers, socialize him with as many strangers as possible in a controlled environment and praise him for remaining calm. It’s important to nip his nips in the bud.

Written by a Shiba Inu lover Patty Oelze

Veterinary reviewed by:

Published: 02/06/2018, edited: 01/30/2020

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