Aggressive Dog Training and Socialization

How do you introduce an aggressive dog to other dogs? Dog-aggressive dogs are most effectively socialized without aversive techniques and when they set their own training pace.


Going for a walk with your dog may be one of your favorite ways to exercise and relax, but your pleasant outing can quickly turn into a stressful one if your dog seems to hate other dogs and you happen to encounter one running loose. If the other dog is threatening or if you have an aggresive dog, a dog fight could ensue, and the situation can become downright dangerous.

Like most owners of antisocial dogs, Thea McCue of Austin, Texas, is well aware of how quickly an outdoor activity with her dog can stop being fun. Wurley, her 14-month-old Lab mix, is a happy, energetic dog who loves to swim and go running on the hike-bike trails around their home. But when he’s on-leash, he barks at other dogs, growls, and even lunges.

Because Wurley is 22 inches tall and weighs 60 pounds, he can be hard to handle, says McCue. “When he pounced on one little 10-pound puppy, it was embarrassing for me and scary for the puppy’s owner!” Indeed, introducing a puppy to a dog-aggressive dog may be one of the scariest experiences a dog owner can have!

Why Are Some Dogs So Hostile Toward Other Dogs?

If, like Wurley, your dog is reactive to other dogs, you are far from alone. Tense encounters between dogs are not unusual, as dogs that don’t get along with other dogs now seem close to outnumbering those who do. In fact, dog-on-dog aggression is one of the most common behavior problems that owners, breeders, trainers, shelter staff, and rescue volunteers must deal with. So what to do with an aggressive dog?

The major reason why dogs become aggressive toward other dogs, says Dr. Ian Dunbar, founder of the Association of Professional Dog Trainers (APDT), is that during their puppyhood, dogs are often deprived of adequate socialization with other good-natured dogs. As a result, many pups grow up with poor social skills, unable to “read” other dogs and exchange subtle communication signals with them.

Regular contact with playmates is necessary for dogs to develop social confidence. The current popularity of puppy classes is largely due to Dunbar’s pioneering efforts to provide puppies with a way to experience this vital contact with one another. If puppies miss out on these positive socialization experiences, they are more at risk of developing fear-based provocative behaviors. Because dogs that show aggressive tendencies tend to be kept more isolated than their socially savvy counterparts, their anti-social behavior usually tends to intensify as they get older.

How to Train an Aggressive Dog

Fortunately, there is a way out of this dilemma. If your dog attacks other dogs, or just really doesn’t like other dogs, the good news is that new aggressive dog training techniques are being developed that can help you resocialize your dog. Like McCue, who opted to take Wurley to “Growl” classes, you may find these training remedies can improve your dog’s manners so that you can feel comfortable handling him in public again.

Although the techniques themselves may be new, Jean Donaldson, author of Culture Clash and training director at the San Francisco SPCA, says that they are solidly grounded in behavioral science theory and the “laws of learning.” Though different trainers design their own classes differently, in general, “Growl” classes are geared to teach dogs to associate other dogs with positive things, and to teach dogs that good behavior in the presence of other dogs will be rewarded.

The first method commonly used in dog aggression training classes involves simple classical conditioning—the dog learns that the presence of another dog predicts a food treat, much as Pavlov’s dogs learned to associate the sound of a bell with dinner coming.

Operant conditioning is also used to teach the dog that his own actions can earn positive reinforcement in the form of treats, praise, and play. Both types of conditioning attempt to change the underlying emotional that leads to aggression in dogs, rather than just suppressing the outward symptoms.

Outdated Ways of Socializing Dogs

This approach is a departure from the past; only a few years ago, most trainers recommended correcting lunging and barking with a swift, hard leash “pop” (yank). Although this forceful method could interrupt an aggressive outburst, it seldom produces any lasting improvement—it does nothing to change the way the dog will “feel” or react the next time he sees another dog.

In fact, this sort of punishment sometimes exacerbates the problem by sending the wrong message to the dog; he learns that proximity to other dogs brings about punishment from the owner! Teaching him to anticipate scolding whenever another dog is nearby is not how to calm an aggressive dog.

Punishment results in additional negative side effects. A dog who has been punished, just like a person who has been physically or verbally rebuked, usually experiences physiological stress reactions that make it harder for him to calm down. Also, when a dog growls at other dogs or shows signs of unease and is punished, the dog may simply learn to suppress his growling and visual signals of discomfort; the result can be a dog that suddenly strikes out with no warning.

These are some of the reasons that behaviorists like Dunbar and Donaldson now believe that it is absolutely necessary to eliminate all punishment and reprimands when dealing with a dog who is aggressive to other dogs.

Training an Aggressive Dog: 4 Components of an Effective Program

In the most effective aggression-retraining programs, unpleasant or punishing training methods (“aversives”) are avoided as much as possible. Aggressive dog trainers control the dog’s behavior by putting the dog on what is known as the “No Free Lunch” regimen. The basic premise is that the dog must respond to an obedience cue in order to earn every right, freedom, and privilege. These include meals, treats, toys, play, games, walks, and even attention and petting. The goal is to teach the dog to appreciate his owner as the provider of all good things in his life.

Meanwhile, the first step in specifically dealing with the dog’s aggression might merely be rewarding the dog for any behavior that does not involve fighting or aggression. His behavior is then modified through a planned program of:

  • shaping (reinforcing each small action the dog makes toward the desired goal);
  • desensitization (presenting other dogs at sufficient distance so that an aggressive reaction is not elicited, then gradually decreasing the distance);
  • counter-conditioning (pairing the presence of other dogs with pleasant things);
  • training the dog to offer behaviors incompatible with aggression on cue.

An example of the latter would be short-circuiting a dog from lunging by having him instead do a “sit-stay” while watching the handler. Eventually, the dog can even be trained to offer this behavior automatically upon sighting another dog. (“If I turn and look at my handler when I see a dog, I’ll get a sardine—yum!”)

Another cornerstone technique, originally developed by behavior counselor William Campbell, is commonly known as the “Jolly Routine.” An owner is taught to use her own mood to influence her dog’s mood—when your dog is tense, instead of scolding, laugh and giggle him out of it.

This same technique can work on fearful dogs. Make a list of items, words, and expressions that hold happy meanings for your dog and use them to help elicit mood changes. “The best ‘double punch’ is to jolly, and then deliver food treats,” says Donaldson. “The bonus to this technique is that it also stops the owner from delivering that tense, warning tone: ‘Be ni-ice!’ ”

How to Socialize an Aggressive Dog

The “Open Bar” is one exercise that might be considered an offshoot of the jolly routine, and it, too, makes use of classical conditioning. Here’s how it works:

For a set period of time (weeks or months, as needed), whenever another dog appears, like clockwork you offer your own dog sweet baby talk or cheery “jolly talk” and a special favorite food never given at any other time. The “bar opening” is contingent only on the presence of other dogs; therefore the bar opens no matter how good or badly your own dog behaves. Likewise, the “bar” closes the moment the other dogs leave – you stop the happy talk and stop feeding the treats.

Skeptics may ask whether giving treats to a dog whose behavior is still far from angelic does not actually reward bad behavior. But behaviorists explain that the classical conditioning effect – creating a strong positive association with other dogs – is so powerful that it overrides any possible reinforcement of undesirable behavior that may initially occur. The unwanted behavior soon fades in intensity.

Another advantage of the Open Bar technique is that it can be incorporated into training regimens that are easy to set up, such as “street passes.” Street passes are also a means of using distance and repetition to desensitize your dog to other dogs. The final goal is for your dog to be able to walk by a new dog and do well on the first pass.

All you need to set up a training session using street passes is the help of a buddy and his dog. Position yourself about 50 yards from a place where you can hold your dog on leash, or tie him securely to a lamp post or tree. Ideally, this should be on a street, about 50 yards from a corner, so your friend can pass through an area of your dog’s vision and then disappear.

Your friend and his dog should wait out of sight until you are in position and ready with your treats. At that point he should appear with his dog, strolling across an area within your dog’s sight. As soon as he and his dog appear, open the bar and start sweet-talking your dog as you give him treats. The moment that your buddy and his dog disappear from sight, the bar closes and you stop the treats and attention.

Don’t get discouraged if on the first few passes your dog seems too frenzied to care about you and your treats. Patience will pay off. “It may take 10, 15, or 25 passes, but how many times in a row can he get totally hacked off?” asks Dunbar. “At some point he will calm down.” When he does, he will begin to make the connection with the food appearing and disappearing with the comings and goings of the “cookie dog.”

Similar sessions can be set up in quiet parks or out-of-the-way places.

The handler, with the aggressive dog on leash, should stand several feet off a path, as a friend walks by with his dog, also on leash. Both dogs should have an appetite (don’t work on this right after the dog has been fed!) and both handlers should have really yummy treats in hand to help keep their dogs’ attention on them and to reward the dogs for good behavior.

The dog walker should make several passes, until the stationary dog is able to maintain a sit without lunging. As training progresses, the owner should be able to gradually reduce the distance necessary for his dog to react calmly with what Donaldson calls a “Oh, you again” response when the familiar dog passes by. The same process is repeated as new dogs are introduced into the equation.

Growl Classes

Naturally, the more dogs that your dog can interact with, the better chance he will have to improve his behavior. If the dog has bite inhibition (when he does bite another dog, the bites are not hard enough to break the skin of his victim), Donaldson believes the ideal solution is a play group of “bulletproof dogs” that are friendly, confident, and experienced enough to interact well with him. Unfortunately, this kind of play group is not easy for most owners to replicate on an as-needed basis.

Donaldson says the second best thing is a well-run “growly dog class” just for aggressive dogs, another concept developed by Ian Dunbar. One way these classes differ from regular obedience classes is that everyone in them is in the same boat, and therefore willing to work together to overcome their dogs’ problems.

One of the most comprehensive programs is offered by the Marin Humane Society in Novato, California. Training director Trish King says MHS’s “Difficult Dog” class size is limited to eight dogs and progress proceeds in baby steps.

“The first class is very controlled,” she describes. “We’ve prepared a small fenced area (using show ring gating) for each dog and the first couple of weeks we throw towels over the fences to prevent the dogs from making eye contact. By week three, the coverings have been removed. By the fourth week we have a few dogs in muzzles wandering around each other. The goal is to have the dogs remain under control when another dog runs up to them!”

King says that proper equipment is part of the formula for success. Dogs are acclimated to wearing Gentle Leaders (head halters) for on-leash work and muzzles for off-leash work. Since muzzles can interfere with the dogs’ ability to pant, care must be taken not to let dogs become overheated while using them. No pinch collars or choke chains are allowed.

“We’ve found that most people have already tried to use corrective collars, and they haven’t worked,” says King, “probably because of the lack of timing on the owners’ part, as well as the fact that these collars can set the dog up for identifying other dogs as a threat; they see an oncoming dog, while they feel the pain of the collar jerk, and they hear their owner yelling at them.”

Changing this common scenario begins with teaching owners to keep the leash short but loose. Instead of punishing corrections, MHS instructors use a variety of exercises to train dogs to avoid conflicts.

“We teach dogs to follow their owners, not to pull on leash, to watch the owner, sit, down, stay, and so on,” says King. “We also teach the owners how to massage their dogs, and how to stay calm and in control at all times. More than anything else, the class is to help owners control and manage their dogs.”

Changing the Dog Handler’s Behavior to Manage Aggression

Across the continent in Toronto, Canada, Cheryl Smith, who developed some of the concepts used at MHS, also believes that working with owners and dogs as a team is one of the most important components of her Growl Classes. One of the first things that Smith teaches owners is how to take a deep breath and relax about everything. Owners who remain calm are better able to pay attention to their dog’s body language and to observe what triggers aggression.

Without special coaching, owners are likely to do exactly the opposite, thus making the problems worse.

For example, if you anticipate or respond to your dog’s aggressive behavior by tightening up on his leash, you will reinforce his perception that he should be leery of other dogs. If you get upset when he lunges and barks, your emotions will fuel his tension and aggression. If you continue to punish and reprimand your dog after he has started to settle down, you will only confuse him and make him more stressed, because punishment that comes more than a couple of seconds after a behavior is too late – your dog will think he is being punished for being quiet!

In contrast, the right approach utilizes prevention and early intervention. The dog must be prevented from repeating the problem behavior because every time that he does so successfully it will become more entrenched! Interventions may include moving to break up eye contact, using a body block to prevent physical contact or to redirect forward movement, giving a cue such as “Gentle” (open the mouth and relax the jaw) or “Off” (back away), and offering treats to defuse or interrupt tension interactions. Smith says that corrections should be limited to verbal reprimands, time-outs, or the withholding of a reward; further, she doesn’t recommend that any of these corrections enter the picture until the dog is able to respond correctly at least 80 percent of the time.

Dogs Learn at Their Own Pace

Of course, there will be some dogs that don’t respond adequately to any dog-aggression training program. These may require a referral to a certified veterinary behaviorist who can prescribe drugs such as Prozac as part of the treatment arsenal. If you have an aggressive dog, you have a responsibility to ensure his safety and that of others by taking appropriate measures, including the use of a muzzle when indicated.

But no matter how serious your dog’s problem may be, Jean Donaldson advises keeping it in perspective:

“In any discussion of aggression, it bears remembering that the bar we hold up for dogs is one we would consider ridiculous for any other animal, including ourselves. We want no species-normal aggressive behavior directed at any other human or canine at any time, of even the most ritualized sort, over the entire life of the animal? It’s like me saying to you, ‘Hey, get yourself a therapist who will fix you so that for the rest of your life, you never once lose your temper, say something you later regret to a loved one, swear at another driver in traffic, or yell at anyone, including your dog.’ It’s a tall order!”

In other words, keep your expectations realistic. Then, if you stick with the program, the odds are you will end up pleased with the results, like Thea McCue. After completing their Growl Class course with trainer Susan Smith, owner of Raising Canine in Austin, she and Wurley are once more able to hit the hike and bike trails together again. Describing Wurley’s progress thus far, McCue says, “he warms up to other dogs much faster and rarely reacts to dogs while we’re running.” Although there remains room for improvement, Wurley’s days of pouncing on puppies are over!

Beverly Hebert is a freelance writer and a dog trainer from Houston, Texas. This is her first article for WDJ. Thanks to trainer Sandi Thompson of Sirius Puppy Training in Berkeley, California.


  1. I have a 5 year old male dog and now two pups but the older dog has started attacking the male pup and the pup is only 12 weeks old. I don’t know what to do!

    • I would separate him from the puppies. No interactions at all.
      It’s too dangerous for the puppy even with an e collar.

  2. Can I put a new dog with a aggressive dog because I am looking at getting a nother dog and was wondering if I can put a nother dog with 7 years old dog that has not been around other dogs

  3. I have a rescue dog – he’s been with our family one week now. He’s been great so far when socializing with other dogs at the dog park. He has walked away when other dogs have shown aggression. He has shown some leash aggression, which has not been too troubling, because I can easily work with him on this. Today we went to the dog beach and he suddenly became outwardly aggressive to two separate dogs while off the leash. He listened to verbal commands initially, but the second time I had to physically separate him, and he lunged for me. He was surrendered by his previous family after being with them for five years. He’s a beagle mix, but I’m not sure what he’s mixed with – either boxer or pit bull. I’m not sure how well he was socialized by his previous family, or the type of training he had, but I’m not sure if the root cause of his sudden aggression today. It’s not consistent with how he’s behaved. Any suggestions?

  4. We are sponsoring a 10 year old poodle/shihtzu for one week. Would like to adopt the dog. He is wonderful with people, unruffled by thunder, loud noises. Not aggressive or interested in our pet birds and hamsters. However, he is very aggressive toward other dogs. When we walk him he goes crazy when he sees other dogs– barking,growling etc. According to the shelter he was raised with a “brother” that was adopted separately. They said the pair were not “very bonded”. The owner was elderly and could no longer take care of the dogs. He is so easy in the house, totally trained, barks to indicate he needs to be walked. How can we socialize an old dog ? Is it possible at his age?


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