Definitive Guide: What Is Dog Reactivity?

barking dog

* All Sniffspot articles are reviewed by certified trainers for quality, please see bottom of article for details *

Do you have a reactive dog, or suspect you may have one? You’re not alone! Reactivity is common in dogs, and is not something to be embarrassed about. In this guide, we’ll go over what reactivity is (and isn’t), what causes reactivity, and what to do if your dog is showing signs of reactivity.

What is reactivity in dogs?

The American Kennel Club defines reactive dogs as “[dogs] that overreact to certain things or situations.” This means that a dog’s reaction to a certain stimulus is excessive or out of proportion with the situation. Do you think your dog is “aggressive,” or notice that they bark, lunge or have other extreme reactions? Then you might have a reactive dog.

Reactivity is very common: our own research shows that 75% of dog owners say they have a dog that shows some signs of reactivity.

How do I know if I have a reactive dog?

Once you start observing your dog with this question in mind, you’ll probably know fairly quickly. Does your dog have something that “sets him off”? If so, you probably have a reactive dog.

Look for signs of reactivity:

  • Barking excessively is a common sign of a reactive dog. For example, does your dog bark for what feels like a long time when he hears a skateboard go by, or when the mail carrier comes to the door?
  • Body language is also an indicator. Keep an eye on your dog’s body language in different situations and note what you see. Notice if your dog shows any signs of anxiety or stress. Note that a dog who exhibits stress is not automatically a reactive dog—it depends on the situation. This can be tricky distinction, but try to determine if the reaction seems like “too much” for the situation. For example, if your dog exhibits stressed body language when cornered by a wild animal, that reaction is proportional. If your dog is cowering in fear when the cat walks by, your dog might be reactive to cats (or this specific cat), as they are having an intense reaction to something that is not actually a danger to them. Additionally, body language like lunging or snapping is considered reactive (unless it is appropriate for the situation—like the “cornered by a wild animal” example— but this is unlikely in the life of a modern dog).

Are certain breeds or types of dogs more likely to be reactive?

The answer is tricky. Some breeds have been bred for specific purposes, such as hunting or herding, and this can influence their behavior. For example, rat terriers, bred for killing rats, are likely to become very focused or even seem obsessive if they see a rodent. However, in most cases, this does not count as reactivity. It would only count as reactivity if your dog had a reaction to the stimulus (in this case, the rodent) that was way over the top, and bordered on dangerous for himself or others.

In addition, over the years, different dog breeds have been maligned for alleged tendencies toward reactivity or “aggression” (think of all the negative press about Pit Bulls over the last couple of decades). However, there is no scientific evidence that suggests this is true. 

In an article about leash reactivity (dogs who are reactive while they are on a leash), Sue Brown, MNM, CDBC, CPDT-KA, states “you cannot predict which dogs will be reactive simply by looking at their breed.” She adds that she is not aware of any studies that look at this question. While more research is needed, it is much more likely that a dog’s environment and socialization, not breed, are the key factors in reactivity.

What is not dog reactivity?

dogs playing

It can be tricky to know what is and is not reactivity. Remember the definition of reactivity: dogs that overreact to certain things or situations. To be considered reactive, your dog needs to have certain triggers, i.e. she is reactive to a stimulus.

Here are a few behaviors that are not reactivity, but are commonly confused with it:

  • Rough play: Though this can sometimes seem scary, it’s a normal part of dog interaction.
  • Puppy nipping: Puppies use their mouths to explore, and this often involves nipping, especially during play. While this can be annoying or painful, it is not reactivity, and is a normal puppy behavior.
  • Resource guarding: Dogs will sometimes guard things that are of value to them, such as food (commonly called “food aggression”), bones or sleeping areas. This may come with behaviors such as growling or snapping. However, resource guarding is considered a normal behavior for dogs. It needs to be managed so that it does not escalate to aggression toward the people living in the house with the dog, but in general, resource guarding is not a reactive behavior.
  • Barking or whining when separated from you: this is more accurately classified as “separation anxiety,” not reactivity. 

What causes dog reactivity?

According to the AKC, “genetics, lack of proper socialization, or a combination of the two can cause reactivity.” The “nature vs nurture” debate is at play here, as it is tough to determine what is caused by genetics and what is caused by environment or lack of socialization. For example, if a dog is born to a mother who is reactive to certain stimuli, he will likely become reactive to the same stimuli. However, it’s difficult to say whether this is straightforward genetics, or whether the dog learned this behavior as a puppy by watching his mother. In a puppy’s early life, especially the first twelve weeks, socialization is critical. If a dog is not properly socialized during this time and is observing a parent with reactive behavior, she might become reactive.

Applied animal behaviorist and author Patricia McConnell writes that dog reactivity can be caused by caused by psychological trauma, and compares reactivity to soldiers with PTSD: “Just as a veteran soldier with PTSD can react to a loud noise by throwing herself to the ground, dogs with their alarm systems fixed on HIGH are usually quick to startle to an abrupt noise, or panic when unfamiliar dogs appear.”

Though genetics may play a part, reactivity is a conditioned response that is rooted in fear. 

What should I do if my dog is showing signs of reactivity?

First, don’t panic! As we stated above, many people live with reactive dogs, and it’s ok! You can live a full life with a reactive dog, and your reactive dog can have a full life, too!

Understand your dog’s reactivity: Really observe your dog: when is she calm and relaxed? When is she reactive? She may have a trigger that’s obvious (mail carriers, people with beards, etc) or it may be harder to spot. (Maybe she wildly barks sometimes and you don’t know why—in this case, try your best to listen, watch and get to the root of it! Did someone close a car door outside? Did someone honk a car horn?)

In addition, pay attention to your dog’s body language, as we talked about above. Check out our guide to reading your dog’s body language, and watch for signs of stress in your dog, such as lip licking, facial tension, whale eye (when a dog turns their head but keeps their eyes on you, showing a lot of the whites of their eyes), shaking, or freezing. These signs show that your dog is stressed or worried. If you notice your dog showing these signs, note the situation and environment and see if you can get to the bottom of what’s causing them. (You may have to do this several times to be able to notice a pattern.)

As far as understanding the root cause of your dog’s reactivity: this can be difficult and may be unknowable with some dogs. You may know that your dog barks at tall people with beards, but you may never find out if there was an “inciting incident.” Try to make peace with that fact and just commit to treating the behavior. (Details on how to do that below.)

Take action on a daily basis: 

  • Minimize triggers: Once you know your dog’s triggers, the good news is that you can manage them (to some degree)! Take note of everything in and around your home that you can control. Some common examples are: closing the blinds for dogs who bark at people they see walk by; putting on white noise for dogs who bark when they hear a car or person outside; not having friends with beards over to your house if your dog hates people with beards. Get creative with your dog’s environment to minimize what triggers them.
  • What to do if your dog reacts to a trigger: If you are surprised by a trigger, exit the situation as gracefully as possible, without punishing the dog. For example, if you are surprised by another dog on a walk and your dog is reactive to other dogs, this might look like making a u-turn or crossing the street (safely). The exit strategy will be different depending what the trigger is. The important thing to remember is that you want to get away from the trigger safely, and you do not want to punish the dog (more on that below).


How to make a difference in the long term: 

  • Counterconditioning and desensitization: Counterconditioning is your best friend when you have a reactive dog. What is it? Counterconditioning means “changing the pet’s emotional response, feelings or attitude toward a stimulus,” according to the VCA

What is desensitization? Desensitization, also according to the VCA, means “the gradual exposure to situations or stimuli that would bring on the undesirable behavior, but at a level so low that there is no negative response.” Desensitization and counterconditioning go hand in hand. 

To begin counterconditioning a dog, first, you’ll need lots of high value treats. Take your dog (and your treats) to an area with the dog’s trigger (or where the trigger is likely to appear). Once the trigger appears and the dog clocks it (e.g. you can see the dog observing the trigger, but not yet reacting to it), begin generously rewarding the dog with the high value treats. An example: perhaps you’re out on a walk with a dog who is reactive to skateboards. You hear a skateboard in the distance, and see your dog’s ears prick up, observing the sound. Now is a great time to reward the dog with the high value treats. The goal here is to change the dog’s association from “skateboarders = bad and scary” to “skateboarders = treats are coming.” 

Obviously, the process will look different depending on the dog’s triggers, but that is the basic idea. It is very important to start small and go slowly. At the very beginning, make sure you mark and reward behavior that is even a step in the right direction. Even if the behavior seems incidental or like an accident, mark and reward it. You are gradually building toward “this trigger means good things are coming.”

You can do this process yourself, but you might also consider getting a trainer involved, as they can help you get started with this process. Make sure you find a fear-free trainer who only uses positive reinforcement training, of course. As we’ll talk about below, you do not want to use punishment or fear with a reactive dog (or any dog).

As with any training process, counterconditioning is likely to take a while, and you will have to do it multiple times across many different sessions. Be patient and celebrate victories, even if they seem small!

What not to do

scolding dog

You should never punish a dog for reactivity. Many people are tempted to do this in an attempt to “correct” the behavior, but dog trainers agree it only makes things worse in the long run, as it instills more fear in the dog, and does not deal with the root of the dog’s reactivity.

Punishment also includes things like bark collars, which are devices that produce a negative effect (spraying citronella, vibrating or even shocking the dog) when the dog barks. While these may seem to work in the short term, they are still a form of punishment, are considered by many to be inhumane, and crucially, do not work in the long term. One study on shock collars found that dogs subjected to the shock collar showed more stress-related behaviors than the dogs in the control group. 

Though it can be difficult to resist the urge to punish in the moment, keep in mind that positive reinforcement is a much more effective strategy, and that punishment will only degrade your relationship with your dog.

Further reading and learning

There are lots of great resources for how to live with and train a reactive dog! Here are a few that we like:

Good luck, and remember: you’re not alone, and you can always bring your dog to a Sniffspot for some playtime!

Trainer Review of this Article

There is so much misinformation out there, we want to make sure we only provide the highest quality information to our community. We have all of our articles reviewed by qualified, positive-only trainers.  

This is the trainer that reviewed this article:

Shannon Finch
AnimalKind Training
M.Ed. Humane Education
Karen Pryor Academy Certified Training Partner
Certified Tellington TTouch and TTEAM Practitioner

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