Posted by: Linda Trunell | August 18, 2013

Leash-Reactive Dogs

“Why does my dog go crazy when he is on the leash and sees another dog?”

“My dog is good with people and my other dog, but when she is on the leash and sees another dog, she barks and lunges like she wants to kill them!”

“I can’t walk my dog because he freaks out when we see other dogs and I get so embarrassed.”

As a trainer, I talk to people about many behaviors they want to change.  Lately, it seems like leash reactivity is one of the most mentioned.  Why do so many dogs act like this?  There are several reasons and the first step to helping is to determine the cause of the behavior.

What many people call “leash aggression” is not really aggression at all.  Over-the-top reactions to seeing other dogs could be true aggression in some dogs, but more often it is something else.

Some dogs are just frustrated greeters who get so excited when they see another dog and then never get to interact.  Over time, the frustration builds and the over-the-top reaction becomes worse.

Some dogs are afraid of other dogs and react by barking, growling and lunging to keep the other dog away.  That fear could be caused by even just one previous bad experience with another dog.  It could also be caused by improper or lack of socialization during the puppy and young adult stages of life.

It may also be a fear of the impending leash-pop or collar tightening or other correction the dog receives when he tries to get closer to the other dog.  In this case, the dog begins to associate seeing other dogs with an unpleasant or even painful correction.

leash aggression

Whatever the reason for the behavior, the dog should not be allowed to “practice” it over and over.  It is important to keep the dog under “threshold” as much as possible.  Threshold is the point where the dog is reacting – not thinking.  A dog who is over threshold will not be able to focus on you and follow your cues.

Do not punish your dog by yelling, jerking or pushing. There are effective methods to rehabilitate dog reactivity that do not involve force or pain.  The use of aversive punishment will make the problem worse.

Here are some excellent resources to help you –

Some books on the subject:

  • Fight! – A Practical Guide to the Treatment of Dog-Dog Aggression – Jean Donaldson
  • Help for Your Fearful Dog– Nicole Wilde
  • Feisty Fido: Help for the Leash Reactive Dog– Patricia McConnell, PhD. and Karen London, PhD

Do not give up on your dog.  Changing behavior takes time and patience but your dog is worth it!

Here’s to being our dog’s best friend,



  1. Interesting. I remember when I lived near San Francisco and we went to a huge off leash dark park “Fort Funston” on the beach and in the bluffs. There were literally a hundreds or more dogs interacting all over the place off leash at any one time and you barely ever saw a fight. I think when dogs are leashed up they loose there ability to use natural “dog” language becoming more nervous, non-confident and defensive. Often chained up dogs become more aggressive too. How would you feel if you were chained up and someone you did not know was coming towards you?


    • I see the same thing at the off-leash dog park. When dogs are free to move away from each other they feel safer. They have “fight or flight” instincts. When they are restrained by a leash or chain they cannot flee. I always recommend keeping greetings between leashed dogs very brief (if at all). Even if both dogs seem friendly, if their leashes become tangled or the handler pulls the leash tight things could change in a flash.



%d bloggers like this: