Dog Reactivity vs Aggression in Dogs: Understanding your dog's behavior

Reactive Dogs

I like to think of Reactivity in Dogs as an “over-reaction” to something, it helps me to frame it in a way that I can acknowledge that my dog is struggling with “big feelings” about something and needs my understanding, patience and support - not punishment.

The Fight-Flight-Freeze Response is an involuntary emotional and physical response to something that a dog (or a person!) has when they feel anxious, uncertain, unsafe, scared and/or threatened.

In a dog this “over-reaction” or Reactivity to another dog for example, can appear to be aggressive behaviors like barking, growling, and lunging.

My dog has been attacked a few times, and so his involuntary response to another dog showing hackles and a hard stare, or stiffening up (which he identifies as a pre-cursor to an attack), is to exhibit a "Fight" response - growling and lunging at the other dog.

Reactivity is not always Aggression

Dog Reactivity is not:

  • a dog showing dominance
  • a dog being stubborn or refusing to listen
  • a dog being a “bad dog”


Dog Reactivity can be:

  • a dog that is in pain
  • a dog that is overwhelmed
  • a dog that is over excited or over tired
  • a dog that is frustrated


Consider this situation:

Can you tolerate the sight of a domestic rat (black & white) in a cage? Would you feel different if it is loose instead of caged? How about a brown “wild” city rat running loose instead?

Now imagine that you hear a noise, turn around, and there is a brown rat running towards you - how would you feel?

What would your Involuntary Response be in each of these situations? Could you react calmly, or would your body take over and kick in one of the Fight-Flight-Freeze responses?

Aggressive Dogs

Actual Aggression in dogs can appear to be the same reaction or "over-reaction" to a stimulus, but with an actual intent to do harm instead of just a presentation of “go away” actions to drive the trigger (the other dog) away.

I like to think of my neighbors dog, definitely reactive to seeing another dog, but his response in slipping out of the house past the owner, running across the street to attack my dog is something that I would definitely label as "aggression" and not just "reactivity".  And the fact that he has attacked multiple dogs, not just mine.

Dogs can be both aggressive and reactive. It’s important to focus on addressing the behaviors because training and management of these dogs typically involve the same techniques.

Also remember that threats and displays aren’t inherently aggressive, but may be warning signs that a dog is presenting in an attempt to avoid an altercation - basically telling another dog to “back off”. Things like a hard stare, or hackles (piloerection) can be subtle signs that another dog picks up on, but humans easily miss (I know I have in the past…). "Bigger" and more obvious signs can be barking, growling, and lunging that dogs may need to resort to using if the more subtle signs are ignored by either the other dog or the humans.

Training for Reactive Dogs or Aggressive Dogs

Have you had a sudden onset of reactivity or aggression? Especially in the home, sudden changes in behavior can point to pain as an underlying issue. First have your dog evaluated by your vet.

Next, seek out help from a qualified canine behaviorist or a positive reinforcement dog trainer with experience in dog reactivity. Even a session or two can help you understand your dogs triggers and identify ways to help them (and you) have calmer and safer walks.

Best Equipment for Reactive Dogs

Link to share

Use this link to share this article

Additional Articles