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Aggression in dogs is a serious problem that won’t disappear with love (or discipline). As an expert dog behavior consultant, I’ve spent years helping family pets and shelter dogs overcome aggression issues (you can read about my experience here).
While stopping dog aggression is not an easy task, it is generally an achievable one with perseverance, patience, and a bit of psychology.
Before we get started, let’s make sure we’re all on the same page. Aggression in dogs is a complex topic, and it’s important to agree on terms and their definitions. I’ll keep this as brief as I can.
Aggression is a behavior with the intent of doing harm or the threat to perform a harmful act. This generally includes barking, lunging, growling, snarling, baring teeth, muzzle punching (when a dog hits you with a closed mouth), and biting.
Dominance describes which dog gets access to which resources in a given situation. It’s not a character trait (a dog can’t “have a dominant personality” or “be dominant”). Dominance is generally considered to be an outdated term because its application in dog training was based on shoddy research. The same goes for “Alpha theory” and “pack theory.”
Reactivity is the common behavior problem of dogs that bark, lunge, snarl, or snap during walks. These dogs are generally friendly in other contexts but become “a different dog” when they’re on a leash or behind a fence. This is one of the most visible versions of aggression. In general, reactive dogs are all bark and no bite – many of them are actually barking and lunging because they’re overly excited to go say hi. That doesn’t mean reactivity isn’t a serious behavior concern, though!
Resource guarding is essentially aggression that occurs only in the context of food, toys, attention, or another resource. It is a natural behavior, but severe cases are generally considered a sign of significant insecurity on the dog’s part. Even though some level of resource guarding is normal (raise your hand if you want to share your ice cream with every stranger on the street), it’s still a cause for concern in many homes.
The distance and intensity where a dog reacts to a trigger. His stress levels, the number of triggers, the speed of the triggers, and many other factors can lower his threshold (making your dog more sensitive to triggers).
The thing that causes aggressive behavior in dogs or reactivity. Common dog aggression triggers include other dogs, strange-looking people, cars, bikes, and kids.
Now that we’ve got all of our technical terms out of the way, we can get down to the nitty-gritty of how to calm an aggressive dog. Let’s start by understanding where dog aggression comes from.
When people realize that their dog is aggressive, they often immediately want to know why. The short answer is that aggression is a normal but uncommon behavior in many animals. In our pet dogs, aggression can quickly become a serious problem, especially if it’s over-the-top.
Almost all dog aggression cases are due to an unfortunate combination of nature and nurture. You may be familiar with dogfight-bust dogs that turn into therapy animals – and I’m familiar with plenty of dogs from loving homes that nevertheless act like Cujo at times. Both situations demonstrate that it’s not “all in how you raise them.”
Living animals and their traits are products of both their environment and their genes – almost without exception.
Think of a glass with water in it. If the water spills over the top of the glass, your dog is behaving aggressively.
The amount of water in your dog’s glass at birth is in his “nature.” This includes your pet’s genetics and hormones.
Genetics and hormones are influenced by your dog’s breed, his individual parents (and their parents, and so on), the experience of the mother while the puppies are in utero, and much more. For example, puppies whose mothers were sick while pregnant might be more sensitive to stress than others.
Each individual puppy comes into the world with a different level of water in this hypothetical glass – even littermates will differ at least a little.
As your puppy ages, stressful life experiences can be thought of as more water being poured into the glass. Good training and positive life experiences may remove water from the glass. The fuller your dog’s glass gets, the riskier the situation as far as aggression goes.
If your pet’s glass is always almost full because of unfortunate genetics and a rough environment, his threshold for aggression will be much lower. He’ll be easier to “set off.”
Some dogs are naturally more resilient – maybe they have a taller glass, or they just had less water in it, to begin with.
This analogy also reflects the fact that adverse life experiences (a bad trip to the groomer, a dogfight, a super-scary thunderstorm) can literally change how your dog’s brain is wired and how his genes are expressed.
In other words, your dog’s environment can change his brain.
READ MORE: 8 Natural Anxiety Remedies for Dogs
The good news is, you can work to lower the imaginary water level in your dog’s glass with the help of behavior modification and medication.
The water glass analogy helps remind us why some dogs seem to “go bad” even in excellent homes (because it doesn’t take much for their glass to overflow) while other dogs endure incredible hardships with a wagging tail.
In short, I can’t tell you exactly why your dog is aggressive. Maybe your dog’s mother got sick while she was pregnant, changing the hormone balances in an unborn puppy.
Perhaps your puppy was undersocialized, making him highly fearful of new things. Maybe your puppy comes from a line of dogs bred for suspicion towards strangers (or even aggression).
Perhaps a series of too-rough games at the dog park pushed your dog to the edge. It could be that your dog is finally fed up with being climbed on by children.
Most dog aggression cases that I see are fear-based or insecurity-based – not based on dominance. Most dogs act aggressively because they want their triggers to go away, not because they’re trying to take over the household.
Fear-based aggression is common in undersocialized dogs. This is also common in dogs that have learned that trying to avoid something doesn’t help, such as dogs that can’t escape a bothersome child in the home or a trigger while they’re on a leash.
Aggression is far less common in confident dogs. Since most aggressive dogs are actually scared, it’s not a good idea to try to “correct” aggression out of them. These dogs have learned that “the best defense is a good offense,” and alpha rolls will only teach them that their owner is scary, too.
We’ll have much better luck with calming aggressive dogs if we help teach them that the world is predictable and safe and that they can get what they want by behaving well rather than acting aggressively.
Don’t believe me? Just ask the thousands of aggressive dogs, from Belgian Malinois and Cane Corsos to Golden Retrievers and Irish Setters, that I helped rehabilitate during my time at the Denver Dumb Friends League.
Let’s be clear here: I’m not a veterinarian, and I don’t have any canine-specific medical training. But I’ve worked with enough aggressive dogs to say that there are times where behavioral medication is helpful or even necessary for treatment.
It’s always a good idea to check with a behaviorally savvy veterinarian (or better yet, a veterinarian that specializes in behavior such as a veterinary behaviorist) to seek a real expert opinion.
There are a few red flags for me that let me know aggression may be related to something medical:
Dogs may become aggressive for any number of reasons if they are in pain. Think of how irritable a child may become with an upset stomach or a sore tooth, and you’ll sympathize. Some disorders, such as hypothyroidism, can also be accompanied by behavioral changes such as aggression.
Even if your dog’s aggression isn’t caused by a medical issue, medication may still help. Some dog aggression medications can help reduce your dog’s baseline stress level enough that behavior modification can take hold. It’s almost impossible for dogs to learn if they’re 100% stressed out 100% of the time, and medication can help there.
A word of caution: some medications are known to lower inhibitions, perhaps by making the dog feel more confident. This can make aggressive dogs more dangerous. Seek the help of a professional when considering medication treatment for aggressive dogs.
In a third scenario, situationally-dependent aggression can be mitigated with medication as well. For some dogs that behave aggressively for grooming, the vet, or medical procedures, a situational tranquilizer might be effective.
All of this should be discussed with your vet, but it’s important to know that medication may be an option that can truly make a difference in aggression cases.
Sometimes, people come to me asking if their dog is dangerous or “red zone.” The reality is, all dogs can bite and would in the wrong situation. That said, some dogs are far more dangerous than others.
Like with most things aggression-related, there aren’t really hard-and-fast rules for determining how dangerous an aggressive dog is.
For example, my own dog Barley will growl if other dogs approach his food bowl. Since we don’t have another dog, this growling isn’t a big deal at all to us. If we’re dogsitting, we just feed him in a separate room. Problem solved.
But in a different home (say, one with multiple dogs and absent-minded roommates who forget to feed the dogs separately) his resource guarding could quickly become a serious problem!
How dangerous your dog is, depends partially on your lifestyle and your training skills.
That said, there are a series of questions that I like to ask people when trying to determine how serious an aggression case is.
Many of these questions are derived from Michael Shikashio’s Aggression A-Z Course, the first course I took way back when I was just getting started in working on aggression cases. The more questions that you answer “yes” to, the more serious your case.
These questions give a relatively good benchmark for how severe your dog’s aggression is. Frequency, intensity, and duration of your dog’s behavior are all relevant.
Whether or not you can predict (and therefore prevent) the aggression is also important. The makeup of your home and your ability to help your dog also matter immensely.
A low score does not mean that a dog is safe, but a high score is almost certainly bad news. I can’t really give you an exact number where a dog is “safe” or “unsafe,” since that’s a personal decision based on your own skill level and risk tolerance, but this score sheet will help you get an idea of how serious things are.
Now that you have an idea of how serious your dog’s aggression is, it’s time to get to work learning how to calm an aggressive dog.
No matter how serious the aggression is, you can use this general framework to train an aggressive dog. Set realistic expectations whenever working with training an aggressive dog. It’s usually possible to calm an aggressive dog, but most formerly aggressive dogs won’t suddenly become therapy dogs.
Keep in mind that it’s always a good idea to get the help of a certified dog behavior consultant, certified applied animal behaviorist, or veterinary behaviorist when working to tame an aggressive dog.
Your neighborhood obedience trainer (or even bitesport competitor) is not an aggression specialist. Trainers who rely on corrections instead of counterconditioning should be avoided.
Meeting canine aggression with corrections will generally either scare the dog or cause more aggression. Corrections may suppress his behavior, but they neglect to change the underlying emotions that caused the aggression in the first place.
The very first step to training an aggressive dog is making sure that everyone is safe. There are several components to this step.
The very first step is to identify your pet’s triggers and thresholds without putting anyone in danger. You may already know what your dog’s triggers and thresholds are (for example, a dog that growls around his food bowl is generally easy to identify), but you might not.
Be as clear as you can about what causes your his aggression. Identify triggers and thresholds by taking extremely careful note of what sets your dog off and what happened right before.
Keeping a journal will help you notice more subtle patterns.
For example, I once had a client whose dog would become aggressive if people smelled of alcohol. It took us a long time to identify that pattern because we kept looking instead of smelling.
Take this time to get to know your dog’s warning signs. Most dogs will show some change in behavior before they become aggressive. Familiarize yourself with the concept of calming signals.
Your dog might shift his weight forward, prick his ears, or slow his breathing. Many dogs will also display dilated pupils (big pupils), pucker their lips or whiskers forward, raise their hackles (the hair along their spine), or wag their tail in a high, stiff fashion.
All of these are warning signs, and it’s time you paid attention to your dog’s “tells.”
Once you have an idea of what triggers your dog’s aggression, it’s time to put in preventative measures.
Preventative measures may include building a fence to prevent your dog going into the street, placing baby gates to separate your dog from the kitchen, muzzling your dog while out and about, not grabbing your dog’s collar, or skipping the dog park.
I talk about using muzzles a lot. I recommend using a Baskerville Ultra Muzzle or Bumas Muzzle for big dogs. Both of these muzzles are safe, comfortable, and allow your dog to eat treats while he’s wearing it.
We will use lots of treats in training because food-based rewards are one of the best ways to show your dog that he’s done something you like (and treats are much more effective than praise).
The goal is to avoid aggression triggers and keep everyone safe. We will gradually reintroduce your dog to his triggers at the next step.
Now that everyone is safe, it’s time to lower your dog’s stress levels. Let’s go back to our water glass metaphor for a moment. Any extra stress in your dog’s life is likely to add water to your dog’s metaphorical water glass, making him more likely to react aggressively to something.
In other words, reducing his stress levels isn’t just a feel-good, kumbaya recommendation. It’s a safety imperative.
There are five main factors to consider when reducing your dog’s stress levels:
Odds are, you’re already doing a good job with at least a few of these factors already. Let’s look at ways you can improve at each pillar.
Some big dogs simply don’t get enough exercise. While your Great Dane might enjoy lounging around all day, most working breeds like German Shepherds need quite a bit of exercise each day.
It’s hard to muster the energy to exercise your dog after a long day of work, and it’s often challenging to exercise aggressive dogs in public. If your dog is safe to walk outside on a regular basis, jogging or activity walks are my go-to exercise methods for busy people.
If your dog isn’t really safe or easy to walk outside, consider using a flirt pole to exercise him. This fishing pole-like toy keeps your fingers out of the way and doesn’t require much space.
As a general rule, healthy dogs should get at least an hour of activity each day between mental and physical exercise. The exercise doesn’t have to be physically intense, especially for older or less energetic dogs.
Most modern dogs spend a lot of their day being bored while their humans are gone at work. Luckily, there are lots of cheap, fast, and easy ways to exercise your dog’s mind.
As a bonus, mental enrichment is often easier to do for aggressive dogs because you don’t have to leave the house. Puzzle toys, hidden treats, training, and walks in nature are my four favorite mental and sensory enrichment ideas for aggressive dogs.
Puzzle toys are one of the best ways to activate your dog’s sense of smell and challenge his intellect. Throw out his food bowl and get a Kong Wobbler or Snuffle Mat instead. Allowing your dog to work for his food using puzzle toys will activate his seeking system in his brain, which releases the happy-hormone dopamine. In other words, having your dog work for his food is actually more fun!
SEE ALSO: 10 Best Toys for Big Dogs
Best of all, you can leave your dog with puzzle toys while you’re at work. This helps alleviate boredom. I love to hide puzzle toys and treats around the house, allowing your dog to use his nose to find his breakfast.
Training your dog is another great way to improve your bond, build his skill set, and alleviate boredom. Start with some simple but useful tricks like back up, go to your bed, come, stay, and touch my hand.
Finally, take your dog for relaxing walks in nature – use a muzzle if you need to. Keep your dog on a 30 to 50-foot long line and let him sniff around an interesting area, like a local hiking trail or even a quiet urban river path. This walk is really for your dog – let him sniff as much as he wants and go at his pace.
Nature walks are incredibly relaxing for you and your dog. It’s incredible how much less aggressive some dogs become if you simply add regular, relaxing nature walks to their schedule.
Some people (like me) don’t really struggle with the physical exercise and mental stimulation – we love being outside and active with our dogs. Instead, we struggle with teaching our dogs to quietly and calmly “turn off.”
If your dog seems anxious, hyperactive, or hypervigilant at home, it’s time to look into improving his relaxation and rest.
Start by removing the things that stress your dog out or amp him up, if possible. For example, many guard dogs get upset about things that pass by outside. Help them out by blocking their view of the windows and putting on white noise while you’re gone. For the play addicts among us, you might find surprising benefits from putting all of the toys away when it’s not playtime.
Use the SMART x 50 training technique to reward your dog fifty times (per day) for calm, relaxed behavior. Simply count out fifty pieces of kibble and then give your dog a treat every time he lies down, sighs, lowers his head, rolls onto a hip, or looks away from the window. Over time, you’ll guide your dog into being much more relaxed at home.
Another excellent tool for teaching relaxation is Karen Overall’s Relaxation Protocol. This fifteen-day training plan teaches your dog to lie down and tune out an increasingly distracting world. I recommend following this protocol every day during mealtimes for your dog, rather than adding extra treats to his diet.
Teaching your dog to relax using these methods will also help teach your dog to be more “zen” about his triggers, ultimately helping to reduce his aggression.
I’m no vet, but it’s also no secret that your dog’s physical health affects his behavior. From an abscessed tooth to thyroid issues to gut imbalances, there are myriad ways that your dog’s physical well-being could be causing or worsening his behavior.
Pay a visit to a behavior-savvy vet and talk to her about your dog’s behavior concerns. She might be able to help you pinpoint physical issues that are related to your dog’s aggression.
Keep in mind that fixing your dog’s physical ailments might not resolve the aggression issues, even if they were the root cause. For example, a dog might start growling when kids come near because he’s arthritic and their rough play hurts his hips.
Giving your dog painkillers might fix the arthritic pain, but he’s likely still got bad feelings about kids thanks to his past experiences. He’s learned that kids make him hurt, and the absence of pain might not fix his feelings about that.
The next step in our training plan will help get rid of those bad feelings.
Now we’re ready to pull out the big guns. You’ve got all of your safety measures in place, and your dog is fully taken care of. If you’ve done steps 1 and 2 correctly, you already should have seen a dramatic reduction in your dog’s aggression.
Some people choose to stop here. Depending on what your dog’s issues are, that’s just fine. Everyone is safe and your dog is happy.
But if you really want to calm an aggressive dog, you’ve got to get into counterconditioning and desensitization.
In essence, these long words boil down to the concept of slooooowly introducing your dog to his triggers in small doses, while teaching him that those triggers always make awesome things happen.
It’s easier to look at this through a few examples. We’ll carry these two dogs through to step 4 as well.
Shasta growls, snarls, snaps, and even bites if other dogs come near his food bowl. He can tolerate dogs that are roughly 10 feet away from his bowl but gets tense if they come closer.
Shasta is learning that other dogs coming near his food bowl makes hotdogs rain from the sky. How cool is that?
Bear barks and lunges when he sees people on the street. He might bite if someone got close enough, but his owners haven’t tested that theory to find out (good for them). Bear notices strangers that are across the street but doesn’t bark and lunge unless they’re closer than that.
Again, Bear is learning that his former trigger actually makes hotdogs rain from the sky.
There are two huge things to keep in mind when working on counter conditioning and desensitization: this takes time, and the trigger should always make the hotdogs appear.
Don’t expect to be able to cure your dog’s aggression in a day, a week, or even a month. Be patient and consistent. Counterconditioning and desensitization is simple, but it’s not easy. The guidance of a trainer is helpful in determining how hard to push your dog. When in doubt, go slower with your training.
The consistency of trigger = hotdog is also super important. If your dog’s trigger sometimes predicts food and sometimes predicts a correction and sometimes predicts nothing, he’s likely to become more stressed rather than less stressed.
The video below shows me demonstrating counterconditioning and desensitization to loud noises. You can practice these techniques with nothing more than a few treats and a Youtube video!
Finally, it’s time to think of what you’d like your dog to do in a given situation other than react aggressively. Many people rush this step, trying to force their dogs to sit when their dog sees a trigger when their dog is so stressed by the trigger that he can’t even hear them (or feel their hand pushing his butt down).
If your dog is still staring at the trigger, you’re not ready for this step.
Wait until your dog is able to be around his triggers without exploding at them. Teaching him to do something when he’s around his triggers is more effective at reducing stress than just teaching him that triggers = hotdogs (see the research behind this here).
Let’s go back to our two example dogs to illustrate how to do this.
Shasta’s owners would like him to drop food on cue. Rather than teaching him to share his food bowl with another dog, they also would like both of their dogs to go to their beds on cue rather than getting into a fight over food.
Bear’s owners would like Bear to touch his nose to their hand, then follow them away if he’s nervous about a stranger.
Teaching a replacement behavior is the fun part of calming an aggressive dog in my opinion, but it can take a while. Ensure that your dog is rock-solid at the target behavior (sit, go to bed, target, or whatever else you choose) long before you start asking him to do it around his trigger(s).
When picking a replacement behavior, select one that isn’t a “dead dog behavior.” A dead dog behavior is anything that a dead dog can also do, such as not barking, not jumping, not lunging, or not biting. Instead, pick a skill that you can teach your dog.
My favorite replacement behavior is a hand target or a down. These skills are generally easy for you to teach and are highly effective at preventing your dog from acting aggressively – he can’t bite your guest and target your hand at the same time.
Nobody’s perfect, and mistakes are to be expected. If you’ve done a good job at step one (take care of yourself and those around you), mistakes shouldn’t involve blood. Always do the best you can to avoid mistakes, but be prepared for something to happen.
When I make a mistake with my dog, I have two jobs: react well, and learn from my mistake.
Reacting well to your mistakes (or your dog’s mistakes) means trying to react calmly and positively, without negative emotion. That can be really hard when you’re scared or angry, but it gets easier with time.
Remove your dog from the situation and give him something else to do. I often put dogs away with a chew (like a stuffed Kong or a dried pig’s ear) if I’m scared, angry, or otherwise trying to figure out how to get over a mistake. Then, I make a plan for improving next time.
This approach does a few things:
Don’t worry about accidentally rewarding your dog by feeding him a chew toy after a mistake. Trying to punish your spouse or roommate after an emotional outburst will only build resentment, whereas giving your human partners an ice cream cone after a fight will help smooth over the elevated emotions.
The same goes for your dog! Trying to punish or correct your dog’s aggression may stop the aggression at the moment, but it breeds resentment, fear, and/or more aggression.
This topic can get a bit hairy, but you can read an excellent (and technical) explanation of if you can reward emotions with treats from here.
Once you’re ready to face your dog (and your training) after a mistake, it’s time to come up with a plan. Honestly assess what went wrong and why, and come up with a game plan for how you’ll prevent a similar mistake in the future.
Let’s look at a real-life example.
Years and years ago, I fostered a German Shepherd that I’ll call Ginger. I was rather new to working with aggressive dogs at the time. Ginger is extremely reactive towards other dogs and will bark, lunge, and snarl with incredible force when she sees them. We generally walk at odd hours and off the beaten path to avoid other dogs.
As I responded to a text on my phone, another dog came out of a house down the street and started walking towards us. I didn’t notice in time, focused on my phone. Ginger immediately started to bark and lunge. I was scared, embarrassed, and my fingers were being squeezed tight by Ginger’s pulling on the leash.
I managed to pull us together by grabbing a fistful of treats from my jacket pocket and hauling Ginger away into an alley, where I dropped the treats all over. Ginger refused to eat at first, staring towards the edge of the alley, scanning for the other dog. Eventually, she started eating, and I took a few minutes to breathe.
I was furious at myself (and Ginger), but I tried to calm myself while Ginger ate the treat scatter. I talked to her in a happy, soothing voice to calm both of us down. Before heading back out into the night, I made a few adjustments to our walk:
I readjusted my jacket and bag of treats and vowed to be more aware on our walks. We walked home that night without a hitch, and spent the next few weeks teaching Ginger not to bark and lunge at other dogs. She was adopted about two months after that incident and is doing very well.
Try to think of every mistake as a learning opportunity, as valuable information. This will help keep you calm and objective.
Not all stories featuring aggressive dogs have happy endings. Sometimes, an aggressive dog will simply be happier and safer in a home with no kids or no other dogs. Other times, there is really no “good” outcome for an aggressive dog.
This topic is huge, and we can’t give it enough space here.
In general, you have three options in determining what to do with an aggressive dog: keep him and train him, rehome him to a rescue or a friend, or humanely euthanize him.
Ideally, dogs stay in their homes and get the help they need. That’s almost always our first course of action.
But there are many cases where an aggressive dog would actually do better in a different situation. In that case, get a certified dog behavior consultant on board to help you assess if it’s safe to rehome your dog. Shuffling an aggressive dog off to a rescue simply makes him someone else’s problem, and that’s not what I’m suggesting here.
If you can easily picture what would make your aggressive dog safe to live with but you can’t provide it, there’s a good chance he’s a candidate for rehoming.
However, if your list of what your dog needs in a new home is miles long (or if he’s caused damage to people or dogs in the past), he might not be a good candidate for rehoming. People generally aren’t lining up outside of shelters to adopt dogs with bite histories.
Similarly, it’s incredibly difficult to find homes with no kids and no dogs and no men and no visitors. Dogs with multiple triggers or unpredictable aggression are risky and difficult to rehome. It’s flat-out irresponsible to rehome a known dangerous dog in some situations.
If you’ve got a truly dangerous dog, the best option might be humane euthanasia. I highly recommend reading this blog on the subject if you’re facing this difficult decision. There are no easy answers, but sending your dog off to live a lifetime of isolation and boredom in a sanctuary or no-kill shelter is arguably worse than death.
If you decide to euthanize your aggressive dog, I urge you to try to be there with your dog if possible. When I worked at Denver Dumb Friends League, owners sometimes abandoned their aggressive dogs in the middle of the night with notes.
In the morning, the shelter staff read the notes and conducted their assessments. If the dog was deemed too aggressive for rehoming, the dog was euthanized. His last night was spent scared and alone, and he died in the arms of strangers.
Get professional help before making the decision to rehome or euthanize your aggressive dog. A trained professional will be able to give you far more personalized advice and help you weigh the pros and cons of each potential outcome.
Aggressive dogs are inherently dangerous. They are threatening to cause damage or have already followed through on that threat.
If you do nothing else when trying to calm an aggressive dog, keep everyone safe. This means understanding your dog’s triggers and thresholds, reading his body language, and using appropriate prevention strategies such as muzzles.
Use non-confrontational training methods to teach your dog that his triggers are actually hot dog machines, then teach him a replacement behavior. Work with a professional if at all possible.
Are you living with an aggressive dog? What advice has helped you? We’d love to hear your personal experiences.
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