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How To Stop Canine Aggression

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My Dog Is Aggressive – What Can I Do?

Having an aggressive dog can be challenging. And many owners feel overwhelmed by having to control a canine that is aggressive towards other dogs or humans. Some aggressive dogs even attack members of their own families. In these situations, people feel they have no choice but to give up their pet. And we agree that your own safety, and the safety of everyone in your household, has the utmost priority. But there are measures you can take to improve the situation. In this article, we will see what exactly causes canine aggression, and how you can help your dog succeed in life.

Is My Dog Aggressive Or Reactive?

Typically, people call dogs that growl, bark, and snap at humans or other animals “aggressive”. But more often than not, these dramatic displays of “aggression” are simply the warning signals of reactive dogs: By growling and barking noisily and excessively, these dogs are trying to keep perceived threats away - either from themselves, from their family or from their territory. Reactive dogs want to create distance between themselves and the other party, but they do not want to bite them. They still might do if provoked, or cornered. But injuring anyone is not the intention of a reactive dog’s loud and somewhat exaggerated communication. These reactive dogs are usually very sweet and devoted towards their family, and most of them would never hurt their loved ones.

Truly aggressive dogs, however, might bite their own family members, including children. Such bite-incidents can be quite severe, with the dog biting down hard. This goes far beyond play-biting: Depending on their size, aggressive dogs can inflict serious injuries on humans, especially on young children. Unlike reactive dogs, such canines are not acting out of suspicion, stress, anxiety, insecurity, confusion or fear. Aggressive dogs are neither stressed nor insecure. And they are certainly not fearful. Many of these individuals are naturally dominant. Yet, not all naturally dominant dogs are aggressive: They are typically highly confident and assertive, but dominant canines can be very calm and balanced in temperament. However, naturally dominant dogs can become aggressive.

Let us illustrate the difference between aggressive and reactive dogs with an example. For this, we assume you are sitting on a park bench. Your dog “Bosco” is calmly lying beside you on a leash. Then, a stranger approaches your bench and starts bending down towards your dog, wanting to pet him. If Bosco is reactive, he may start to growl, or to bark loudly and repeatedly at the person. He may either try to back away, or lunge toward the stranger. In this way, Bosco is clearly “telling” the stranger to stay away.

If Bosco were an aggressive dog, he might not display any signs of fear, nervousness or concern at all. He might stand up, but he would not back away. Bosco would cock his ears forward and maybe move toward the stranger to sniff their hand, tail confidently raised up, and perhaps wagging. Bosco might even allow the person to pet him. Apparently, Bosco is behaving completely normal – just another friendly dog happy to meet and greet a stranger. If you closely observed his body language, however, you would see Bosco become very still after a few moments of the stranger petting him. He might avert his gaze, turn his head to the side, or fixedly stare at the stranger. And unless you act quickly, Bosco could lash out and bite that stranger a moment later, seemingly “out of the blue”.

This absence of apparent warning signals is what sets aggressive dogs apart from reactive dogs. At the same time, it makes people more likely to get bitten by them than by reactive canines. After all, strangers are unlikely to pet a growling, barking or air-snapping dog. But most people would reach out and touch a dog that is approaching them, sniffing them and wagging their tail.

4 Causes Of Canine Aggression

There are comparatively few truly aggressive dogs. As we said, most dogs that appear aggressive are merely reactive. Aggressive canines are typically confident by nature, and they do not share the reluctance of reactive dogs to touch another being with their teeth: In the absence of insecurity, fear or confusion, aggressive dogs may bite someone as hard as they can – and then move on as though nothing had happened. But why do some dogs behave like that? Let us list four causes for aggressive behaviour towards other dogs, humans, or other animals.

1. Genetics

At least to some degree, aggression is hereditary: The tendency to act aggressively is passed down from the canine parents to their puppies. For example, certain bloodlines of dedicated working dogs are born with high levels of confidence and prey drive. These breeds include Rottweilers, Dobermans, Belgian Malinois, Dutch Shepherds and German Shepherds. Some of these dogs are selectively bred to chase and bite decoys on the training field, often in preparation for their work as personal protection dogs or military- and police service canines. To excel in these demanding roles, these dogs require high levels of confidence and strong protective instincts. They need to be ready to defend their handlers, should the need occur. This genetic predisposition makes them far more likely to become aggressive towards strangers than naturally sweet-tempered sporting dogs or gentle hounds. Other examples for confident breeds that are more prone to aggressive behaviours towards strangers than the average dog include the Caucasian Shepherd, the Fila Brasileiro, the Akitas, the Chow Chows and the Husky.

Breed-specific aggression is not confined to large canines: Even toy-sized companion dogs can attack other pets and people. Breeds like Schnauzers, Pinschers and Terriers in particular were designed as tenacious catch-dogs for rodents. This is why even small, innocent-looking Jack Russel Terriers or Miniature Pinschers can attack and bite people and other animals.

And some particularly powerful dog breeds were originally created for the blood-sports of dog-fighting and bull-baiting. Even today, some so-called breeders pride themselves with producing puppies with high levels of inborn “game-ness” – in other words, aggression towards other animals, mostly dogs. If an unsuspecting person then rescues such a dog from a shelter later on in their lives, they can be confronted with a dog that aggressively attacks canines, cats and other animals. And any American Bulldog, Presa Canario, Pitbull, Tosa or Dogo Argentino with severe animal aggression can become a serious problem: These dogs are immensely strong and equipped with a high tolerance for pain.

We are not saying that bully breeds or mastiffs are generally aggressive, as this is not the case. And there are many reputable breeders out there who focus on breeding healthy and even-tempered dogs. Under the guidance of an experienced canine leader, even dogs with inborn tendencies for aggression can succeed – and become perfect canine companions.

2. Absence of Leadership

Here at Fenrir, we speak a lot about the importance of calm, consistent leadership. In our opinion, such leadership is the foundation for a harmonious life with our dogs. Dogs that look up to their owners for guidance and direction are far less likely to engage in aggressive lunging, snapping or biting.

Once you have established a loving leader-follower relationship between you and your dog, they will take their cues from you - rather than making their own decisions. They might still act aggressively in certain situations: for example, to guard your family and your home. But once your dog truly accepts you as their leader, they will refrain from breaking your rules. These rules may include “attacking other dogs is unacceptable”, or “resource guarding is not allowed under any circumstance”. Canine instinctively understand that inappropriate behaviour is unacceptable in the presence of “the boss”.

If your dog is responding aggressively to anything in their environment, they are (usually) not looking up to you for guidance and direction in that moment. And this means that your leadership with your dog is broken. But without leadership, there is no working relationship between the both of you. Dogs without leadership can experience all kinds of negative emotions. This makes lack of leadership the root cause for sometimes chronic states of stress and frustration. In the absence of leadership, dogs make their own decisions – such as to attack everyone who approaches their food bowl. Such behaviour is stressful and frustrating for everyone involved, including the dog: Canines thrive under loving leadership, and forcing them to try and be that leader themselves puts tremendous stress on them.

Of course, even dogs with calm, consistent leaders in their lives will feel triggered sometimes by certain stimuli – such as dogs barking at them from behind fences. But as these dogs trust their leader to guide them through any situation, they are far less likely to respond with aggression.

3. Lack Of Socialisation

Lack of socialisation is a common cause for aggressive canine behaviour. Ideally, everyone would socialise their young puppies to many different stimuli. They would desensitise them to vehicles, busy streets, dogs, other animals, and many different men, women and children. If this is not done, the dog may react with nervousness, anxiety or aggression to these stimuli.

The best way to prevent inappropriate behaviours is to socialise puppies to as many things as possible. This includes exposing them to many different situations, circumstances, objects, nature spots, buildings, surfaces etc. As our own neighbourhood may only offer a certain number of these different environments, we should routinely take our dogs to different places. Even if we do this, there will always be sounds, sights and situations that are unfamiliar to the dog. But a well-socialised canine will be able to stay calm in the face of all these stimuli.

One of the most common forms of aggression is leash-aggression. Leash-aggressive dogs may be fine otherwise, but as soon as the leash comes on, they pull, lunge or snap at other dogs and sometimes people. Understandably, most dog owners do not enjoy walking severely leash-aggressive canines. So, they walk their dogs less often. Some owners even stop taking them out into public altogether. But the resulting lack of exercise and ongoing socialisation often leads these owners into a vicious cycle where their leash-aggressive dog receives less and less exercise. This increases their frustration and pent-up energy, which intensifies their undesirable behaviours.

But all dogs need exercise and mental stimulation on a daily basis. And usually, they require far more of it than we think. Not getting enough physical and mental stimulation leads to the dog’s nervous energy building up and up – until it eventually boils over. And if we fail to provide positive ways to release this pent-up energy, it can express itself in severely aggressive behaviours.

4. Traumatic Experiences

Sometimes, aggressive behaviour is rooted in strongly negative or even traumatic events that occurred earlier in the dog’s life. Puppies in particular are veritable little learning machines: Their impressionable young minds soak up every information they can get from their environment. This makes them vulnerable to negative experiences. But it also gives us the opportunity to influence their development through socialisation, training and leadership. Even with our best intentions, accidents can happen: Aggressive adult dogs can attack and bite our puppy. Men, women or children can unintentionally hurt them. And if we rescue an older dog from a shelter, we may never know what kind of traumatic experiences have shaped their psyche when they were young.

How To Rehabilitate An Aggressive Dog

Now that we have discussed possible causes for aggression, let us see how we can help our dogs to adequately respond to anything they might encounter in their lives. Before we delve into measures you can take to help your dog improve, we ask you to put your own safety - and the safety of your family – first. And if you feel right now that you are in any danger from your aggressive dog, we ask you to seek help immediately: Do not wait until an accident happens. Be proactive, and reach out to an experienced balanced trainer or behaviourist in your area. Ideally, such a person would come to your house and work with your dog hands-on. An alternative to this approach are board-and-train programs designed to rehabilitate aggressive dogs. By removing the dog from the situation for a few weeks, an experienced canine professional can address the problematic behaviours, and work on rehabilitating the dog.

1. Getting Help

If your dog is acting aggressively towards yourself or your family, we advise to avoid direct confrontations with them. Instead, call in a local trainer or behaviourist. Again, your safety, and the safety of everyone involved, has the highest priority. And physically correcting an aggressive dog is not always safe, because they can redirect their attack onto the person closest to them. This is how some owners get bitten by their own pet – simply because they gave them a pop on the leash, or they tried to physically remove them from the couch. We are not saying that physical corrections are “bad” in any way. And in aggression cases, we have to find ways to modify potentially dangerous behaviours. But if you have an aggressive dog in the house, trying to tackle their aggression head-on is not advisable.

Before you start contacting the canine professionals in your area, we recommend you set up an appointment with your vet. Ask them to perform a detailed health-check on your pet. Sometimes, aggressive behaviour is rooted in medical problems such as thyroid disorders, brain tumours and neurological disorders. Treating such ailments can reduce a dog’s problematic behaviour considerably.

2. Managing Your Aggressive Dog Out In Public

Having an aggressive dog can be very challenging, but it is not the end of the world. If your canine companion is under your control at all times, they are less likely to cause accidents than friendly but out-of-control dogs that knock people over and run into traffic. We are not suggesting that you ignore aggressive behaviour. But not every aggressive dog needs immediate intervention from a trainer or behaviourist. Let us say, for example, that you completely trust your dog with yourself, your family and your guests. But your canine companion just does not like other dogs, and acts aggressively whenever another dog enters their personal space.

In such a case, trying to force your dog to “play nice” with others might achieve the opposite result. What you can do, however, is to ensure your dog has perfect manners and obedience. A dog that looks to you for guidance and direction at all times will not pose a danger for other canines – unless, of course, their owners choose to let them approach your dog off leash. But as your dog’s calm, consistent leader, you can control not only your own dog, but also your environment. And there is nothing wrong with asking owners who are letting their dogs run lose to keep their pets away from yours. In most countries, the law will be in your favour as long as your own dog is on a leash.

To ensure that your aggressive dog is under your control at all times out in public, we recommend using high-quality and extra-safe tools, such as our Ragnar Slip Leash. Should the need occur, this strong and durable leash will withstand any amount of aggressive lunging and pulling.

And the same applies to the Ragnar Harness. Both products effectively keep aggressive dogs safe during walks – much safer than a simple flat collar ever could: Many dogs have learned to slip out of standard collars. With an aggressive dog, this is a risk that no responsible owner can afford. Its dual traffic handles make this harness the perfect tool for keeping aggressive dogs under control at all times: Whenever you find yourself in a situation that triggers your dog’s aggression, simply grab the handles. This allows you to prevent your dog from lunging at other dogs, running into traffic, or jumping up on people. At the same time, the comfortably padded Ragnar Harness gives your dog the freedom to explore the world - without harming their throats by pulling.

3. Building Leadership

With an aggressive canine in our home, we have to step up our leadership. We need to become the calm, consistent leaders that our dogs need to succeed. But how can we do this? One great way to start is by setting clear rules, boundaries and expectations for our dog. Then, we consistently reinforce these rules, boundaries and expectations.

Dogs with calm, consistent leaders in their lives have no reason to react inappropriately to people, other animals, or unfamiliar events. This in itself can mitigate tendencies for aggressive behaviour. Once you have become your dog’s calm, consistent leader, you are no longer the victim of your pet’s aggression. Instead, you are in the driver’s seat. In this position (and only in this position), you can effectively control your dog. Aggressive dogs are often naturally confident and dominant. And this is not a bad thing. Canine units in the police force and the military, for example, favour such so-called “Alpha”-males and females. Because they know that strong, confident dogs are ideally suited for performing highly demanding tasks under pressure. Less confident dogs would falter under such pressure.

This is why having a strong-willed, dominant dog can be a valuable asset. All you need to do is channel their energy into positive directions. One great way of doing this is by participating in canine sports. Joining a canine club has many benefits for owners of aggressive (or potentially aggressive) dogs – such as getting access to a community of experienced dog handlers and trainers. These people can help you to become a better leader yourself, and to modify any undesirable aggressive behaviours. Canine sports and protection work in the context of a reputable club also allows you to strengthen the bond with your dog. After all, you will be operating as a team, and prepare for competitions and events together.

Hiring a local behaviourist or balanced trainer is also recommended if the problematic behaviours persist despite your efforts. Getting professional assistance for your aggressive dog does not make you a “bad” owner, on the contrary: It proves that you are willing to do whatever it takes to help your canine companion succeed.


As we saw, genetics play a powerful role in canine aggression. Certain breeds, and certain bloodlines within these breeds, have a lower threshold for aggressive behaviours than the average dog. We cannot alter our dog’s genetics. And neither can we wind back the clock, and undo any traumatic experiences from earlier in their lives. But when it comes to rehabilitating aggressive dogs, there is a lot that we can do. And rehabilitating aggressive canines is often easier, and faster, than helping fearful or anxious dogs.

By taking our dogs on generous walks, we provide them with exercise, socialisation and mental stimulation. Whilst we keep them (and everyone involved) safe with the harness or slip lead we mentioned, we can work on simple obedience drills – such as heel walking. Doing so strengthens our relationship and solidifies our leadership. With this combination of exercise, discipline and loving leadership, we set our dogs up to win.

We from Fenrir are here to help you, and we encourage you to believe in yourself, and in your dog: There are always ways to improve your life with your canine companion - – no matter their temperament, breed, age or history.