Skip to main content


We’re on a mission to provide resources and practical tips to pet people

What is Reactivity in Dogs?

‘He’s reactive’ or ‘I have a reactive dog’ is quite commonly heard nowadays, and is a bit of a catch-all label that gets put on dogs who respond in a certain way. So, what is reactivity really, and what is a ‘reactive dog’?

A dog who is reactive is generally one who overreacts in certain situations, or to certain things (science calls these stimuli) in their environment, and this overreaction can vary in intensity, how long it goes on for (duration), or volume.

Cartoon of dog barking
Reactive behaviors can appear scary.

Common triggers of reactivity in dogs can include, but are not limited to:

  • Other dogs
  • Other animals
  • People
  • Noises such as fireworks
  • Heavy or noisy traffic

Dogs may become reactive due to genetics, a lack of appropriate early socialization, inappropriate training such as using aversive techniques or being exposed to trauma or a bad experience. Dogs who live in high stress environments are also more likely to become reactive, as they are constantly above the threshold of stress that they can cope with.

Here it gets more complex. Sometimes it is either/or and sometimes it is both together, with fear related reactivity tipping over into frustration and vice versa.

Reactivity can be driven by frustration, ‘I really want to get to that dog and just say hello’ or fear, ‘That dog is scaring me! I want to get to them to tell them to go away!’ and there are lots of other scenarios too.

Lunging, growling, and barking are behaviors all commonly seen in reactive dogs, and these behaviors can appear scary to passers-by or to other animals.

Very often, reactivity looks like an “aggressive dog,” and people don’t realize what a hard time the dog is having in that situation.

A common example of reactivity in dogs is when a dog really, really wants to get to another dog to say hi, and feels frustrated that they are on leash. We often call these dogs ‘frustrated greeters’ and they may or may not greet a dog more appropriately if off-leash; however it’s generally not safe to do so, and it’s not teaching them any coping skills.

Addressing a dog’s reactivity will involve a step-by-step process and include:

  • A vet check – Dogs should always be given the medical all clear before we start to work on their behavior.
  • Understanding the root cause of reactivity and identifying the dog’s triggers
  • Management to prevent dogs from being in situations that cause them to overreact
  • Behavior modification techniques such as counterconditioning and desensitization to help change the way the dog feels about triggers, which involves introducing stimuli systematically over time, guided by a qualified canine behavior consultant
  • Positive reinforcement training for day-to-day life to ensure the dog gets to make lots of good choices that can be rewarded – this type of ‘polite’ behavior then becomes the default. Yippee!

Changing behavior takes patience and consistency, and can sometimes appear slow, but it’s important to not lose hope! A professional trainer or behavior consultant can be that extra pair of eyes on assessing your dog and working through a structured behavior modification plan, as well as giving you the moral support you need while you’re working through these challenges.

For help with training your dog, be they a rescue or a new puppy, download the Zigzag app.

About the Author

Petrina Firth is a Dog Trainer and Certified Animal Behaviorist of over 10 years who now mainly specializes in Separation Anxiety (CSAT) and also creates content, lessons and articles for the Zigzag puppy training app and website. Petrina is a member of the Pet Professional Guild, the head of marketing and board member for the APDT UK, and a member of the CAPBT committee. She is also a tech and gadget enthusiast who enjoys city living with her rescue French Bulldog and partner.

The Zigzag logo

Zigzag  is a puppy training app with a difference. Rather than focusing solely on obedience we take puppy guardians on a journey through Life Skills and important developmental stages, to hopefully give them happy, confident and well-behaved puppies, with an understanding that puppies and dogs aren’t robots, they have big feelings, and that’s ok!

Zigzag is a Pet Professional Guild corporate partner.

Spread the love