Stranger Danger: Why Your Dog Doesn’t Like Strangers

Last updated on:

My dog, Juno, is afraid of people. Not all people ring the five-alarm bells though: it’s not like she cowers to hide from everyone. She mostly just has no interest in saying hello to anyone outside her circle of human friends. 

However, people who come into (her) house or people who are just standing around on the street (not walking, running or on a bike) raise her suspicion levels. And, people who try to say hello to her are the worst suspects of all!

She will quickly let me know: “Stranger Danger!”

Stranger danger is a fear towards unfamiliar people. It can cause your pup to run and hide, or can cause her to react aggressively. 

But, why might a dog be so afraid of strangers? Why can’t she give them the benefit of the doubt – especially if they’re offering a tasty treat?

If you’re struggling with a dog with stranger danger, you’ll also benefit from checking out these articles:

What Causes Stranger Danger?

Why are some dogs so fearful of strangers? Have they been traumatized in the past?

Some dogs, perhaps, have had a bad experience with strangers or certain people. But the majority of dogs who are fearful of strangers haven’t had any notable trauma.

Take Juno, for example. She was a rescue at 10 weeks old. We took her to puppy classes, we socialized her to as many people and situations as we could. 

But she was already fearful of new people (among other things) at a very young age. And she still is!

Fortunately, I have been able to work with her from the beginning of our time together and she has learned some excellent coping skills. But why, then, is she so fearful?

Genetics Influence Behavior (And Fear/Anxiety Levels)

Genetic make-up might predispose some dogs to stranger danger. A new study shows that a fear of strangers has a high genetic component (in fact, 60-70%!)

This makes it increasingly important to find a reputable breeder in the unregulated sea of dog breeders out there. 

Prenatal Stress Hormones

It might begin before she is even born. Studies have shown that if mom is stressed during her pregnancy, her offspring may be more likely to be anxious or fearful adults.

Early Socialization Can Help or Hurt

Although I was able to start socializing Juno early (10 weeks), I still missed about 7-weeks of her critical socialization window.

All puppies between 3 weeks and 16 weeks need to have positive and controlled exposure to as many situations, animals, people, contexts and experiences as possible. 

Their brains are developing rapidly and they are making new neural pathways to all the different stimulus they will experience throughout their lives.

Under socialized puppies are much more likely to develop fear and anxiety related issues into adulthood.

Overdoing socialization in a shy puppy can also backfire, though.

Letting groups of people crowd your puppy and invade her space is called “flooding” and can seriously backfire instead of teaching your puppy that people are harmless!

Aversive Training Tools Can Backfire

Shock collars, prong-collars, pinch collars and aversive training techniques that use force or intimidation can increase both fear and aggression

One way that dogs learn is through the associations that they make with their environment.

For example, the sound of your car pulling into the driveway may cause your pouch to get ulta-excited. Or the jungling of her collar may cause her to run happily to the front door. These are good, positive, emotional responses to cues in her environment.

On the other hand, negative associations can also occur.

If your dog gets a zap from a shock collar every time she lunges at a person walking by, she may very quickly associate people in general with bad, negative feelings.

Thus, we can create or exacerbate a fear of strangers by using these types of tools.

Trauma Can Cause Doggie Stranger Danger

Trauma or abuse does not necessarily mean your dog will all of a sudden become fearful or anxious around strangers. However, if your dog is predisposed because of one or all of the reasons above, she could become fearful of strangers, particularly if there has been repeated abuse.

Conditioned Emotional Response and Learned Behavior

Dogs who are afraid, switch into their fight of flight mode when they are feeling frightened. Their brain is flushed with hormones that tell them they need to get the heck out of there! 

But what happens if there is no where to go? 

Maybe the stranger is coming into their home or they are on a leash. If there isn’t an option to flee, then fight it must be! 

This is when dogs begin to react to their trigger by acting aggressively in order to make the danger (stranger) go away. And it probably works! Most people steer clear of a reactive dog and your pup learns that this tactic works. 

Over time, your pup develops a conditioned emotional response (CER). She has made an association between the trigger (strangers) and negative, anxious feelings. 

She then learns that in order to ease her fear, the reaction of barking, lunging and/or growling will make the stranger leave her alone. 

The trigger (strangers) then begin to increase her anxiety and she may become more and more worried about what is happening in her environment.

What Does Stranger Danger Look Like?

Generally by the time I am called to do a behavior consultation, a dog is reacting overtly fearful and/or reactive. She may be barking, lunging, and/or growling or she may be shaking, cowering and frozen in fear. 

Because I am able to see Juno’s very subtle and early signs of stress, she (almost) never becomes reactive or frozen in fear because I am able to keep her under threshold (never allowing her to feel overwhelmed or unable to tolerate the trigger). 

But I also have had years of practice and I have worked with hundreds, if not thousands, of dogs who are anxious and fearful. 

I am also extremely aware of her environment and what is happening. I am very watchful and vigilant to make sure that I can set her up to be successful. Most people are not skilled at reading these subtle signs of stress or priming their brain to scan the environment for triggers.

Subtle Signs of Stress or Fear

Body language can tell us a lot. This is how dogs communicate. Some more subtle (and often missed) signals include:

  • Lip licking
  • Averting gaze
  • Dilated pupils
  • Ears back
  • Lowered body position
  • Yawning
  • Whale eye
  • Exposing belly
  • Wagging tail with short reach
  • Tucking tail
  • Stiff body

Some of these early warning signs can indicate when you are approaching your dog’s threshold level. This is good because it means you are able to turn away from the situation before it becomes one of concern.

Overt Signs of Reactivity

  • Lunging on leash or at the window
  • Gowling
  • Hard stare
  • Barking
  • Showing her teeth
  • Off leash she may bark and lunge then back away

Larger Signs of Fear

  • Freezing
  • Moving in slow motion
  • Trying to escape or run away
  • Cowering

Once you have reached this level of fear and/or reactivity, your pup is well over her threshold level. She likely will have a hard time re-focusing, won’t want to take treats and won’t “listen” to you.

How Do I Help My Fearful or Reactive Dog?

If your dog has become reactive, aggressive, or is showing early signs of being fearful of strangers, I highly recommend contacting a professional behavior consultant.

They can provide you with the tools you need to help your dog overcome her fears, become more tolerant, and learn new coping strategies.

Here are some strategies a behavior consultant can help you with:

1. Behavior Modification

  • Engage/Disengage: This is a technique where your dog is rewarded with a delicious high value treat for looking at a trigger. This is the “engage” part. Over time, people become a cue for her to look at you for that reward. That is the “disengage” part. 
  • Look at That (LAT): This is a technique that simply rewards your dog for looking at the person. She looks at a stranger and gets a treat — simple as that! Over time, we change her emotional response to people from something negative to something positive.
  • Behavior Adjustment Training (BAT): This concept uses a functional reward for calm behavior. In other words, when your dog is calm, you move away from what she is afraid of (person) as the reward.


All of these techniques utilize some forms of desensitization (slowly allowing exposure to strangers at a tolerable distance and amount) and counterconditioning (slowly changing her emotional response from a negative one to a positive one when strangers are present). 

Disclaimer: Because the timing and positioning is so key to success with these methods, I suggest working with a professional to help you get started. They will be able to provide you with the tools you need to work through these processes daily.

2. Training

A part of the solution might be to teach your dog an alternative appropriate behavior. This won’t work for any dog who is above their threshold, and you should still work on behavior modification.

Out on walks you might try to following cues:

All of these cues can help you to redirect their attention and make a plan of action before they plunge over that threshold line.

You will need to practice these behaviors before attempting them in the face of a trigger so that your dog is clear on what they mean without being overly distracted.

In the house, try:

3. When in Doubt, Distract!

Distractions can be helpful to get you out of a tricky situation. Sometimes when we are out for a walk, people can surprise us, or situations eliciting a fearful reaction are unavoidable. 

Bring some extremely high value treats with you. This might be beef liver, cheese, hot dog pieces, steak, tuna, or anything your dog finds irresistible. You might find a squeeze tube full of peanut butter or Cheese Wiz works for you.

When you find yourself in a close encounter, try a treat scatter (toss a handful of treats as a distraction allowing the stranger to move away) or try squeezing some peanut butter into your dog’s mouth in order to lure her in another direction.


It is ok for your dog to be selective and to choose who she would like to socialize with and who she chooses not to. As long as we provide her that choice. 

Providing choices can empower your pup and help her to feel more in control of her environment. And the more in control she feels and the more predictable her environmental cues are, the less anxious she will feel. Always remember to be gentle and kind. 

As we say in the dog behavior world, “Your dog is not giving you a hard time, she is having a hard time.”

Happy training!

Leave a Comment

This site uses Akismet to reduce spam. Learn how your comment data is processed.

Join up with our pack

Get tons of great dog training tips and tricks you won't find anywhere else, along with exclusive deals and discounts only for pack members.