Freak on a Leash – Why Dogs become Leash Aggressive

Leash aggression is probably the most common complaint that I hear from people about their dogs when it comes to aggression issues. In addition to that, if I had a penny for every time I heard “it’s funny, he’s totally fine when he’s off leash, but as soon as we go for a walk on leash, he goes crazy!”, well, my favourite rescue would be rich!

I’m currently working with a beautiful, 2 year old Boxer boy named Jersey. He adopted his Mom Cathy in June of this year, and she contacted me within of few days of bringing him home. When I arrived, not only did I see Jersey have a freak out (and that’s a technical term folks) when another dog walked up the opposite sidewalk, Cathy also showed me how one side of her body was totally black and blue from Jersey turning on her. This is a behaviour called redirected aggression, wherein the dog will react to a stimulus (usually another dog), and will turn on the person holding the leash, the dog he is walking with, or basically whoever is closest to him. Not only was Jersey a threat to other dogs (introductions on leash had not gone well), he was also dangerous to Cathy. This required some serious intervention.

The funny thing about Jersey, and actually most dogs with leash aggression, is that he can play wonderfully with dogs so long as he isn’t attached to the leash. He has dog friends over in his backyard 3 or 4 times per week, sometimes up to 3 dogs at a time, and has never had an issue with any of them. He greets new dogs nicely, he adjusts his play style depending on the breed, and can even share treats and toys with multiple dogs without any reaction. This has formed an important part of his rehabilitation, and he continues to have several puppy play dates per week.

So the question is, what does Jersey have an issue with? Other dogs, or the leash? This example, and many others, prove that the majority of leash reactivity issues are directly related to the leash – not to dogs specifically (though dogs that are reactive to humans, on or off leash, may have different issues are should immediately be seen by a professional). In addition, leash reactivity is a learned behaviour that is often taught in response to a young dog who begins to be excitable when another dog approaches on walks, and in an effort to control the dog, the owner is actually causing the dog to develop reactivity issues. This is most commonly the result of aversive equipment like prong/pinch collars, choke collars or inappropriately used martingale collars, but can also result from something as simple as a strong verbal correction (“No!! Leave it!! Bad!!”).

As you’ve learned in my other blogs, dogs (in simplified terms) learn by association. Dogs produce a Sit behaviour so reliably because it is so often followed by a desirable result (reinforcement), like getting fed, getting a treat, or getting to go out for a walk. This premise applies with punishment as well, except it is much more challenging for the dog to figure out exactly what they are being punished for, and they can easily make the wrong association. If the common denominator in a situation where the dog is punished is always the oncoming dog, they will believe that they are being punished because a dog is approaching them. Even though the owner believes that these corrections are clearly being delivered because the dog is getting excited and jumping around, unless that dog did exactly the same reaction in exactly the same place and was punished at exactly the same point each time, it’s difficult for them to ascertain what specifically the feedback is for. In the example of Sit, it’s pretty clear to the dog that when they put their bum on the floor, good things happen – it’s a simple action for a dog to recognize and an owner to reinforce with good timing. If you think about the last time your dog acted out (negatively or positively) on leash with respect to an oncoming dog, consider how many physical behaviours he demonstrated inside that small amount of time. Also consider how many different ways you’ve responded to your dog when he does that, and then from the dog’s perspective, try to figure out exactly which thing is the same every time. Well, every time, there was a dog coming towards you.

The dog will quickly develop a method of communication that will attempt to keep the oncoming dog away from him, because in his mind, the closer the other dog gets the more he gets in trouble. Yet, in most settings, the dog is not able to keep that dog from approaching him, because the oncoming owner is innocently continuing on their walk. Following that, the opposing dog will eventually go away – again, because that owner is simply continuing his walk – so in the dog’s mind, his communications to that dog have finally been effective. In the dog’s mind, it goes like this “I’m on a walk, this is great! Look, there’s a leaf! Gotta pee, gotta pee, peed on a fire hydrant! Wait a minute – is that a dog I see? OMG it’s a dog! My Mom HATES other dogs!!! She’s gonna yell at me! And I’m stuck on this leash so I can’t get away from her, and I can’t do what SHE wants and get away from this dog!! Grrrr….dog go away!! Bark – get away my Mom will yell at me if you get closer!! Stop approaching – I’m getting yelled at because you’re coming closer!! Grrr!! This is awful now you’re right in front of me!!! Get away!! …..ahhh ok you’re going away now. Oh thank goodness that’s over. Phew – well at least my barking and lunging was effective and made that dog go away and Mom stopped yelling at me. Next time I’ll have to yell louder so he goes away faster….”

Funny as it may sound, it’s actually quite a frightening experience for the dog. The behaviour of communicating to the other dog to go away (what we call leash reactivity, or leash aggression) is so important to them, they will even perform the behaviour regardless of how harsh the corrections become, and this is why so many people report that the prong collar works but only for a couple of months or so. Dogs will work through a great deal of aversion if it results in the oncoming dog going away. Forcing the dog into greeting the oncoming dog, or forcing them to repeatedly pass other dogs and increasing correction, will reinforce the dog’s belief that aggressive responses result in the elimination of their problem – the other dog leaves. However, because dogs operate on a fight or flight response, this theory also explains why so many dogs are fine off leash. They have never made the association of collar jerking, an owner getting their face and shouting, or even a painful stimulation from a collar, with greeting a dog in an off leash area. They are very much aware of the fact that they are not being physically controlled in these situations, that they are free to make a choice about how they interact with the dog, and they have never learned that off leash greetings result in a very angry owner. This is a key distinction, and a major part of the rehabilitation process in leash aggression.

Some trainers will attempt to control the leash aggressive dog by increasing the corrections and getting the dog to ignore the oncoming dog, or sit when a dog appears. When this is effective, what is in fact happening is the dog shuts down completely and hence doesn’t respond, but is still feeling the same fear and aversion to dogs that he did before this new training began. This can be quite dangerous, and in fact results in a dog becoming a time bomb – eventually, he will not feel overwhelmed by the handler, or the oncoming dog will feel so threatening that he has to lash out. Often, the handler is not expecting this because they feel the dog’s issues have been resolved, and the dog either overpowers the owner and gets away, or the owner attempts a greeting and the dog bites the oncoming dog.

The most effective way of resolving this issue is changing how the dog feels about being on the leash in the first place. If he learns that being on leash no longer results in being frustrated, confused, overwhelmed and often in pain, the desire to stave off other dogs approaching is no longer necessary. When the dog begins to believe that other dogs mean GOOD things will happen, he will actually welcome other dogs approaching! In essence, you have not only eliminated the reactive behaviours that are really what upset the owner, you have eliminated the dog’s need to react at all. You have accomplished a well mannered, happy-to-be-on-leash dog who does not behave because he is physically controlled, but behaves because he feels no need not to! Unless significant changes occur in the dog’s life and the corrections return, this behaviour modification will be permanent, will be present for any person (including children and elderly) walking the dog, and most importantly, mean that you have caused the bond and level of trust with your dog to increase, rather than deteriorate as happens with heavy correction training.

Jersey is coming along well in his training, and is now beginning to learn that when he sees a strange dog on the street, what he is supposed to do is turn and look at Cathy for instruction, and be reinforced for a very appropriate behaviour. Instead of barking, lunging, and biting at her, he is instead walking calmly by her side and looking at her. Doesn’t that sound like a much nicer way to walk your dog?

Reversing leash aggression is a lengthy process that needs to begin with very basic desensitization to the leash. Please contact a positive training professional for help with this work!


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One Response to “Freak on a Leash – Why Dogs become Leash Aggressive”

  1. Thank you so much. This is the best article I have read on “leash aggression” and I have been trying to find a solution to my problem for 5 years…!!! Notice too that many of my friends and other dog owners are focused on this issue as well. I’ve been a dog owner, airedales and other terriers, for a really long time, but just in the last decade has leash aggression become a problem. Very helpful explanation and I will be sending it on to friends.

    Linda Tegarden on at 7:37 pm

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