What Is a Reactive Dog? Signs and How To Help

Victoria Schade, CPDT-KA
By Victoria Schade, CPDT-KA. Reviewed by Tiffany Tupler, DVM, CBCC-KA on Feb. 1, 2024
black and white dog barking in grass

Most dogs will bark when they see a stimulus, or something that alarms them like a stranger at the door or a deer in the yard. But a reactive dog takes it to another level.

The intensity and level of response from a reactive dog will appear overly dramatic or out of proportion to the stimulus. A dog might continue barking for much longer than necessary or might be unable to focus on anything else even after the triggering stimulus has disappeared.

While reactivity in dogs can often look and sound like aggression, it’s actually an overreaction that’s rooted in distress, either from fear, excitement, or frustration.

Reactive Dog Body Language

It’s easy to confuse the body language of reactive dogs with an aggressive display, because many of the behaviors look similar. Reactive body language in a dog may include:

  • Barking

  • Growling

  • Lunging

  • Spinning

  • Extreme vigilance

  • Restlessness

  • Whining

  • Hunched posture

  • Inability to focus

What Makes a Dog Reactive?

Reactivity can stem from a variety of sources, including a dog’s genetic predisposition (for example, herding behaviors taken to the extreme), past negative experiences, a lack of socialization or training, or the dog’s environment.

A barking, growling, lunging dog might appear as purely aggressive, but reactivity is typically either a fear-based response or related to frustration and excitement. Take, for example, a dog viewing a stimulus through a fence or trying to reach the stimulus while on a leash.

How To Help a Reactive Dog

There are two ways you can help a reactive dog: with management and through training.


One of the easiest ways to help deal with dog reactivity is managing the environment to prevent the behaviors from occurring. Management doesn’t involve training, but it’s a straightforward way to help keep your dog more comfortable in challenging scenarios.

For example, if your dog gets overstimulated when guests arrive, keep him in a quiet spot, like in their crate with a chew toy, until everyone has arrived and is settled.

If your dog is at a window and reacts to a stimulus outside, you can install an opaque window sticker to obscure the view.

Unlike training, management doesn’t change the dog’s response to a trigger, which means that the reactivity will resurface if the management technique fails, like if the sticker covering falls off the window.


The only way to bring about true behavioral change in a reactive dog is with science-backed, positive reinforcement training. The goal in reactive dog training is to shift your dog’s association with the stimulus by pairing it with something positive (usually food).

Identify your dog’s trigger and understand the distance at which your dog can see it and remain calm. For example, your dog might feel slightly nervous about a human runner in the distance, but an entire cross-country team headed your way might be more than your dog can handle.

The goal is to keep your dog focused on you when the trigger is present; a dog that has begun reactive behavior is more challenging to work with.

Training a Reactive Dog

The goal of training is to reduce your dog’s reactivity by changing their emotional response to a trigger. The process is straightforward:

  • Begin feeding a constant stream of treats when your dog sees a trigger in the distance. Keep a safe buffer zone from the trigger before your dog exhibits reactivity.

  • Continue feeding your dog until the trigger is out of sight, even if your dog barks. Remember, you’re making an association to the stimulus, not rewarding specific behavior. If your dog is unable to focus on you, you’re probably too close to the trigger.

  • Once the stimulus is out of sight, praise your dog for a job well done!

  • Repeat this process whenever your dog spots a trigger. This will take time, especially if your dog has a long history of “practicing” reactivity.

  • Eventually, your dog will anticipate treats when they spot a trigger and will look to you for a treat instead of fixating on the trigger. This means that your dog has begun to form a positive association, and you can slowly start to address the other parts of the training equation, like moving closer to the trigger.

Keep in mind that backsliding can happen. Getting results when training a reactive dog will probably take longer than you think!

How To Socialize a Reactive Dog

“Socializing” a reactive dog depends on the definition of the word. If the goal of socialization is the traditional version (involving off-leash play) and the adult dog in question has a long history of reactivity toward other dogs, it might not be possible. That said, calm acknowledgement of other dogs in the area during a walk is within reach with enough time and training.

The same goes for dogs that are reactive toward people. Getting to the point where your dog is a canine ambassador who happily gets pats from others might not be possible, but you should be able to progress to the point where your dog is comfortable being in the presence of strangers without barking at them.

When figuring out how to socialize a reactive dog, it’s important to:

  • Be your dog’s advocate

  • Recognize what their body language is telling you

  • Not push your dog into an uncomfortable situation

Tips for Pet Parents with Reactive Dogs

Yes, living with a reactive dog is challenging, but there is hope! In addition to training, keep the following tips in mind:

  • Don’t punish your reactive dog: This is true of all training and behavior scenarios. Punishment, whether from physical “corrections” to yelling, is based on outdated and disproven training techniques, and it can have serious behavioral fallout, as well as a negative impact on the bond between you and your dog.  

  • Consider your dog’s health: Sudden or escalating reactivity may mean that a dog is dealing with undiagnosed health issues, such as pain or reduced vision. Schedule a trip to your veterinarian to rule out illness.

  • Relax, and mind the leash: Your response to reactivity can have an impact on your dog’s behavior. Try to keep tension out of the leash, and don’t forget to breathe!

  • Exercise your dog: Frustration-based reactivity can stem from a lack of exercise, so make sure to work your dog’s brain and body. Play with your dog and try some enrichment games like “find the toy” or trick training to help chip away at your dog’s exercise needs.

Featured Image: Adobe/Mary Swift

Victoria Schade, CPDT-KA


Victoria Schade, CPDT-KA

Animal Trainer

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