When a dog owner comes to me for training I always ask detailed questions about what kind of issues and behaviors that are occurring with their dogs. A very common phrase I hear a lot is “my dog has leash reactivity” or something similar, and once I delve a little deeper with my questions I realize that a lot of people are misdiagnosing their dogs or, in many cases, other dog trainers have misdiagnosed their dogs.

What exactly is leash reactivity? Aggressive or threatening behavior displays from a dog which are directly caused by being constrained on a leash.

Now that may seem pretty straightforward – and it is – but we can get a much better idea of where the confusion comes from by exploring some examples that are not leash reactivity.

What Leash Reactivity Isn’t

Bad Leash Manners

This is probably the most common way I see leash reactivity get misdiagnosed, especially if the dog is vocal and has a tendency to bark. Not being able to walk nicely on a leash without pulling on you or lunging to go smell things does not mean your dog is leash reactive

Even if your dog gets very excited to see other dogs or go nuts barking and spinning in circles when another dog or human gets near you – that is not leash reactivity.

What is does demonstrate, like all leash pulling, is a lack of clear understanding or respect of the leash and the rules that surround it.

Your dog may be barking and carrying on, looking crazy and making other dog owners nervous. However, if your dog is not showing clearly aggressive body language and behavior towards dogs or people while on leash, that is not leash reactivity.

Aggression in General

This is the second most common way I’ve seen leash reactivity mistaken, and this one is a little more nuanced. It is, however, fairly simple to deduce if this is the case with your dog.

If you have seen any other type of aggressive behavior – lunging and snapping, barking, “face hardening”, ears back or lip lifting and snarling – towards other dogs or people while off leash, it is fairly certain that your aggression problems are not directly caused by being constrained on a leash.

Many dogs with leash reactivity are easily able to communicate and solve any issues with other dogs very well when not on a leash, never showing any kind of aggressive behavior. Many even interact in large doggy daycare groups just fine.

Once they get on a leash, it can almost seem like they become a whole different dog.

It is true that an untrained aggressive dog is almost certainly going to show more of those behaviors on leash than they would off of it. However, the bad news is that kind of general aggression is much more difficult to mitigate and solve compared to simply being reactive to the leash.

Barrier Aggression

I have seen a few instances of both owners and trainer alike using this term interchangeably with leash aggression. While I suppose you can make the case that a leash is a kind of “barrier”, that is not the specific situation attempting to be conveyed with the name “barrier aggression”.

The barrier being referred to is something like a gate, fence, screendoor, kennel or sometimes windows. Something that your dog can see out of, scent out of, can move freely in every direction except to where the barrier prevents them.

Often in barrier aggression, all tension is diffused once the barrier is removed – sometimes resulting in comical situations like this:

A dog can be perfect on a leash and go absolutely crazy in a barrier aggression situation and vice versa. One does not always equal the other.

Attacking or Biting On The Leash

Maybe this is the result of imagining a different picture in the mind when thinking of “leash reactivity”, but sometimes I do find people describing a dog that bites on the leash as “leash reactive”.

Often when a dog bites the leash, it is a sign of excitement or frustration that can’t be held in anymore – the same with whining or barking.

However, it is something to look out for and correct for because you should be thinking of the leash as an extension of yourself – and you wouldn’t want your dog to be biting on your hand out of excitement.

The Cause of Leash Reactivity

As you may have already figured out from the rest of this post, the cause of actual leash reactivity is: the leash! There are a couple of reasons that being leashed can cause this reaction in dogs, all of them quite natural.

When your dog is off leash and doesn’t react to other dogs in an aggressive manner that’s because they are free to do what comes naturally.

When being polite to each other, dogs naturally greet from the side to be non threatening and sniff each other’s genitals. Approaching face to face and making constant eye contact is a good way for a dog fight to break out.

A proper greeting also only lasts a couple of seconds. Longer than that can allow tension between the dogs to build.

When we have our dogs on leash, they are unable to go though the full motions of their body language displays and are generally more constricted in their movements than without the leash. This means that when two dogs greet or get close to each other on leash, they can’t communicate to their full extent.

This can have unintended consequences and misunderstandings between dogs and result in behaviors that are intended to create distance – things like barking, lunging, or growling – in order to make the perceived threat go away.

When on leash dogs can often feel trapped, unable to get away from another dog or person that makes them uncomfortable. When having their dogs “meet”, owners often have a tight “death grip” on their leashes, thinking that will prevent something bad from happening.

The problem with that is they are constricting their dogs’ movement even more and adding unnecessary tension to the interaction. That can result in a dog resorting to those aggressive behaviors already mentioned and possibly causing a fight.

We as humans seem to have a strange obsession with always needing to have our dogs stop and “meet each other” along our walk. If you think about it though, do you stop to greet and meet every person you see when you go out? So why would your dog want or need to?

Solutions To Mitigate Leash Reactivity


This is obviously what I would recommend for a vast variety of dog behavior issues, not just leash reactivity. Training your dog to walk nicely on a loose leash will almost always solve your leash reactivity issues.

When your dog knows and respects the rules of walking on a leash, they will trust you to handle situations that arise – like seeing another dog coming towards you.

That trust does come with responsibility. You should never let your dog have a bad experience while you are in charge. Don’t let two dogs meet on leash face to face – or on leash at all.

A trick you can do while training is to make a wide berth around the other dog and approach from any direction other than face to face. Remember to keep a loose leash and do your best to explain to the other owner why that’s a good idea.

Keep in mind that other owners probably didn’t read this article or know how to have dogs properly greet, so something can still always go wrong and a fight can break out. Having dogs greet each other on leash is always risky.