Leash aggression in dogs is one of those phrases we hear regularly. Most dog owners use this term if their dog loses their mind at other dogs, or people, or cars, or bikes, or whatever, when on a leash. Off-leash the dog may even be totally fine. Just on a leash, it acts like a lunatic. And there is of course the close relative of this term, leash-reactivity. Both are used quite interchangeably, so for the purpose of explaining this behavior, I will stick with leash aggression as it is probably more commonly used.
But what does leash aggression actually mean? It’s a pretty useless phrase as it doesn’t provide any kind of description of what is happening. It just indicates that a dog is having an aggressive reaction for some reason.
What Does Reactivity Mean?
The phrase ‘reactivity’ in dogs is something I heard well-known ethologist Rodger Abrantes discuss in one of his lectures. He was making fun of the term. He asked what does it even mean? A dog is reacting in some way? That seems okay because if it didn’t do something it was probably dead. He has a point. Reactions in general are usually not the issue. The issue tends to be the context of the behavior. Is the reaction acceptable or not? Do we need to address it, or not? Is that kind of reaction normal dog behavior, or not? We could ask many more questions. Leash aggression is no different.
The Two Reasons for Leash Aggression
There are generally two main reasons a dog would display behavior owners describe as leash aggression: fear or habit. I personally have probably seen more of the fear-based behavior but I know from other trainers who have seen more of the habitual variety. We will probably never know the true distribution but let us explore what these are about.
1. Fear-Based Leash Aggression
When dogs are confronted with unfamiliar situations they have essentially four response options. Which one they are going to choose depends on their state of mind and comfort level with a given situation. The options are appeasement, avoidance, flight, or fight. Dogs’ response repertoire is limited.
If a dog is being walked on a leash towards another dog that makes it uncomfortable for some reason it can really only do a few things.
Possible Responses to Unfamiliar Situations
Appeasement requires some freedom of movement, which doesn’t exist on a leash. Even if the dog can display clear body language signals of discomfort, they are often neither seen nor understood by its owner. The dog on the other side is also on a leash. So even if that dog would read your dog correctly and would respond appropriately, it can’t. As a result, appeasement is unavailable.
Avoidance would be another possibility but that would mean not getting closer and as they are being moved closer regardless of what would be better for either of them, avoidance is also unavailable.
Flight would be the next possibility, which would mean getting away from the situation altogether, but there is the leash. Hence, flight is also unavailable.
Fight is the last option and that is the response people call leash aggression. Because we have literally made all other options unavailable, fight—going on attack/striking first—is all that remains. So that is what your dog is left with. Once it engages in aggressive behavior it becomes scary. The dog has finally gotten its owner to feel as uncomfortable about the situation as it is itself. Because it's scary now, the dog is being moved away from the other dog and in the process learns that fight—the leash aggression—is the way to go. Getting its space respected is all the dog wanted in the first place and it now learned the fastest way to that goal is acting with aggression. As a result, the behavior is expressed sooner and sooner and becomes stronger and stronger, because it works.
The Solution Approach
The answer to this co-called leash aggression is three-fold. First, we have to build up the dog's confidence. Second, we need to socialize the dog properly, and third, we have to penalize the aggressive behavior—if that is still necessary after steps one and two. Aggressive behavior must start having a price tag for the dog instead of leading to the desired outcome.
2. Ritualistic (Habitual) Leash Aggression
Ritualistic leash aggression is completely different from the first one. A lot of dogs act like idiots on the leash because they think that is what we want. They have no real commitment to that behavior but are engaging in it for our benefit. To them, it is a ritual you engage in together when meeting other dogs. It’s a fun thing to do. A lot of these dogs will act aggressively on leashes when being walked to the dog park. But if they get to go in and let loose, play perfectly fine with other dogs. They neither have so-called leash aggression nor any other kind of aggression. They act aggressively on a leash for fun and recreation when they are with their owners.
The Solution Approach
The answer in this case is simpler. The dog must see the owner interact with other dogs in a friendly manner and be penalized when he acts out. That requires two people but goes rather quickly when done correctly. Let your dog see as often as possible that you like other dogs and expect your dog to be friendly too.
This is easiest with puppies. For that reason, early puppy socialization is critical. Waiting until all shots are complete is dangerous. We should aim to strike a balance between avoiding exposure to serious diseases and early socialization. Far more dogs are euthanized each year due to behavioral issues related to lack of early socialization than diseases.
I hope this makes it clear that both of these possible causes of aggressive behavior on a leash have absolutely nothing to do with the leash itself. So, the term leash aggression is incorrect, imprecise, and meaningless. It doesn't explain what is happening or why. We should stop using it.