Fence fighting is a common term for the phenomenon of dogs hearing or seeing each other through a fence, pen, or gate, and aggressively lunging and barking. It is a form of “barrier frustration,” which can also occur when dogs are on leash, in a car, or looking out a window. The underlying reason may be that the dogs are anxious about each other, or very excited, or a combination of both, but are restricted by the barrier between them and so act out in a frustrated, even aggressive manner.
There are several reasons that this behavior is problematic for us humans:
The resulting noise can irritate neighbors, especially if it’s happening frequently or during “quiet hours.”
It can be just as annoying for the owners of the dogs in question.
It often goes hand-in-hand with leash reactivity (barking and lunging while on leash).
It encourages over-aroused greetings toward other dogs even when off leash.
It can scare passing dogs, especially puppies, and cause them to become leash reactive or anxious during walks.
It can be dangerous to interrupt your dog when he is really going at it - some dogs will redirect and bite someone pulling them away from the fence.
The plan below will teach your dog how to be calm and ignore other dogs (or humans) behind a fence, gate, or pen. It can also be adapted for dogs who are reactive behind windows or in the car.
Management
The first step of any training plan is management - arranging things to prevent your dog from rehearsing the unwanted behavior when you’re not ready for training. Use the following strategies as applicable to your situation.
Don’t let your dog into the backyard without supervision. (This may require locking the dog door.)
If the fence fighting it happening with a specific neighbor dog, talk to your neighbor about a way to keep the dogs from being outside at the same time. For example, your dog can be out during even hours (eg 8:00 - 8:59 am, 10:00-10:59 am, and so on) and their dog is out during odd hours (eg 9:00-9:59 am, 11:00-11:59 am, etc). Or you could text each other, or use some sort of flagging system to let the other neighbor know that one of the dogs is out.
Set up an “airlock” or “no man’s land” in front of the problematic area of the fence, so that your dog can’t get all the way up to the fence. This extra space will greatly decrease the intensity of your dog’s fence fighting, which will make training easier.
Take your dog into the yard only on leash, so that he can’t get to the fence.
Set up an alternate yard for your dog. For example, you can take your dog to the front yard instead, keeping him on leash, on a longer tether, or making a temporary fence using exercise pens.
Training Exercises
With management in place to prevent fence fighting most of the time, you can now set aside time to do training exercises when it’s convenient for you. You’ll need to have high value treats or toys to reward your dog.
Start with simple counter-conditioning: every time that you hear the other dog moving around behind the fence, or see them through it, you immediately hand your dog a treat or play with a toy.
Make sure that your dog FIRST notices the other dog, and THEN you hand him a treat or play. The trigger comes to PREDICT the good stuff.
If your dog immediately starts to bark or lunge, you need to change the situation to help him be calmer. The most reliable way to do this is to move farther away from the fence.
If your dog eats the treat but then starts to get worked up (staring, freezing, hackles up, whining, huffing, pacing), you should move farther away, but also consider scattering the treats on the ground instead of just handing him one. Scatters are calming and help take a dog’s mind off the trigger.
Keep your sessions short and practice throughout the day.
When your dog is expecting the treat every time he sees/hears the other dog - he looks at you with happy anticipation - switch to using the Engage-Disengage Game: let your dog notice the other dog (“engage”), wait, and reward your dog when he looks away (“disengage”).
Here is a lovely graphic from Alice Tong that explains the Engage-Disengage Game in detail.
If you prefer learning via video, here is one from Charleston Animal Society explaining how to teach this exercise, and here is another one from Bravo Dog Training & Behaviour.
If you see that your dog is starting to get worked up (staring, freezing, hackles up, whining, huffing, pacing), you should distract him to help him disengage from the trigger. Then move farther away.
If your dog is happily glancing toward the other dog and then back at you, congrats! He is learning to play the training game rather than fence fight. You can move closer to the fence.
Transitioning to normal life
Start encouraging your dog to do other activities while in the yard, such as sniffing around, chewing, sunbathing, and playing on their own. You can encourage sniffing by scattering kibble/treats, or by setting out items with new smells (eg, leaves or dirt from a park or a friend’s yard, fur or feathers from other animals). For chews, see the recommendations in this article on enrichment. Bring out a new toy (or one your dog hasn’t seem in a while) and let him go to town.
You can reward your dog for choosing to settle on his own:
You should continue to take training treats or toys outside for an extended period of time, so that you can still reward your dog for calmly noticing activity outside the fence. Over time, you can give treats/toys less frequently, but taper the rewards instead of stopping cold turkey.
Don’t leave your dog in the yard unsupervised until you see that he is truly reliable at reacting calmly, even when the rewards are infrequent.
When mistakes happen
In an ideal situation, your dog never rehearses barking or lunging toward the fence again. He is prevented from doing it using management in between training sessions, you’re practicing the training exercises successfully, and he quickly learns to calmly ignore the other dog and do his own thing. Realistically, there are going to be “oopsies.”
When your does end up charging the fence and barking:
Interrupt him and move him away from the fence as quickly as possible, using the least amount of force you can.
Start by calling your dog, and wait no more than 2 seconds to see if he responds.
If he does come to you, reward him for stopping barking! Then quickly bring him into the house to calm down.
If he doesn’t come within 2 seconds, move closer to your dog so that you can more easily get his attention. (The closer you are to his head, the more likely he is to actually notice you. Just don’t stick your face too close to his teeth!) You can tap his butt or side to get his attention, and call again, waiting no more than 2 seconds to see if he responds.
If he does turn back to you, reward him for stopping barking! Then quickly bring him into the house to calm down.
Use a body block: If safe to do so, get between him and the fence, and block his access, like a basketball or soccer player blocking a pass. Then move toward him so he has to move away from the fence. Shift left or right as needed to keep him from going around you. Herd him back toward the house to calm down.
If the body block is unsuccessful, you may need to put your hands on your dog to turn him around and move him away. Be careful. Some dogs will be so worked up from fence fighting that they will whip around and bite anyone that grabs them.
If your dog has previously snapped or bitten at you when restrained or interrupted, he should have a leash dragging from his collar or harness any time he is in the yard. This allows you to safely pick up the leash and guide him away from the fence.
If you forgot to attach the leash or it is bunched up too close to your dog, use a physical object, such as an elevated cot bed, to herd him back from the fence. Note that the object should not be used in a way that scares your dog or adds to the stress of the situation. Stay calm and matter of fact, just blocking and herding him back.
If you’re not worried about your dog biting you, you can take him by the collar or harness and guide him to turn around and return to the house. This should not be done roughly or in a scary or stressful way. Be calm but insistent that your dog leaves the fence.
If you reward your dog for stopping barking and returning to you, won’t he learn to purposefully bark and then come? The answer is no, if you also implement the management and training exercises above. Your dog should be getting rewarded for not barking at the other dog much, much more often than you have an “oopsie” and need to call him away.