Dog-on-dog aggression

on February 03, 2012 at 12:54 PM, updated February 03, 2012 at 3:25 PM

Prevention and management


Witnessing a dog fight can be frightening. It’s violent, loud and when gets the sense that one dog is trying to kill the other. If you’re the owner of a dog-aggressive dog you know first-hand how stressful simple events such as taking your dog for a walk can be.

While many skirmishes may appear as if one dog is attempting to kill the other, most often such fights are little more than loud displays of posturing and rarely do they result in serious injuries.

If wounds are sustained such injuries appear as a torn lip, ear tear or a puncture to the neck. When a dog truly intends to kill another its actions are swift and death can occur in as little as 15 seconds. Attacks intended to kill are most often are directed at the victim’s stomach or on the neck behind the head (an effort to break the spinal column), not in areas around the face or shoulders. Bites and injuries around the face, shoulders and neck are meant as a correction -- one dog conveying to the other that enough is enough! If left to their own devices the fight usually ends fairly quickly and there will be a clear winner and loser. In fights between two average (non-fighting breed) dogs the loser is almost always allowed to walk away and it will avoid future conflicts with the victor.

Assessing Injuries
When assessing dog fight injuries it’s important to take into consideration that an average dog has the ability to crush bone with a bite that can deliver over 500-700lbs of pressure per square inch. German Shepherds, Rotties and Pits in excess of 700 lbs. Armed with such knowledge it’s easy to then understand that even deep tears to the face, neck and shoulders aren’t considered to be those inflicted by a dog with the intention to kill. However, any bite should be considered serious enough to seek the help of a professional trainer.

The Neutering Debate
Dog-on-dog aggression (DODA) is more common among males (often referred to as inter-male aggression), however, females can get into fights too, but it’s less common.
The difference between the two sexes is that male fights are usually nothing more than loud posturing displays and hardly anyone gets hurt, while females may fight to the death—particularly if the two have a history of fighting with each other.

Quite often non-neutered males will aggress toward intact males. This is because non-neutered males smell like males and neutered males smell like females. Regardless of how friendly an intact male may be, non-neutered males are aware that these dogs retain the ability to mate. This poses a serious threat to non-neutered males.

While neutering won’t affect behavior or personality of the dog it can have a profound positive impact on the way non-neutered males perceive him, which can affect positive changes in inter-male exchanges. On the medical side, there are many benefits to neutering. Neutered males live longer. Neutering also helps reduce the dog’s chances of developing some forms of cancer. If the dog is sexually active the risk factors are dramatically reduced. However, if the dog is not sexually active the risks increase.

Common Causes of Dog-on-Dog Aggression
Most dogs squabble over valued resources such as food, territory, water, for mating rights, as well as to establish dominance. Altercations between males is more common when females are present in the social group. In all-male groups males fight less than they would if females were present. This holds true in most species—including lab mice and rats.

In pet dogs another common cause is lack of appropriate social interaction with members of its own species during puppyhood (poor socialization). Pups who are not exposed to all sizes, shapes and ages of polite dogs before 12-weeks of age have a greater chance of developing such social issues with conspecifics (same species) when they mature. In addition if a pup experiences a traumatic event in the presence of other dogs that can become a contributing factor as well.

Another cause is inappropriate play interactions with conspecifics during early puppyhood and adolescence. Rough play with older, larger dogs or at the hands of their humans may contribute toward elevated levels of stress and hyperactivity and can affect a dog’s nervous system for the rest of its life. In fact, there’s compelling scientific evidence that adverse social stresses can cause permanent damage to neuro-connectors in the hyppocampus of the brain—the area of the brain responsible for storing good and bad memories. Such damage also effects the learning process.


When I work on fighting cases careful attention is focused on accurate note-taking regarding the dog’s past experiences. This history-taking helps narrow down possible causes/triggers of aggression and may reveal where and when the behavior started. This is helpful because training programs are influenced by the length of time the dog has been suffering.

However, no matter how compelling a dog’s history may be the most important task is changing the dog’s behavior going forward. On that end management will play a key role in future training processes. The most important rule to such success is that the owner make every effort to ensure the dog does not get into any more fights.

In almost every case I work on clients report multiple encounters—as many as several times per week. It’s critical to the dog’s behavior modification plan that every effort is made to keep the dog calm (and safe) by avoiding such encounters. The less aggressive encounters he experiences, the better.

One element of fall-out from repeated encounters is elevated corticotropin (fear hormone) levels in the brain. Most often it takes nearly 48 hours for these levels to stabilize, which may explain why some dogs become hyperactive, or even destructive, in the days following a thunderstorm, or why one fight seems to closely follow another.

Environmental Factors
Environmental factors play a huge role in how your dog reacts. For example, if most fights occurred on-leash, anxiety may begin building the moment you pick up the leash for a walk. It's common to mistake a dog's hyperactivity for happiness when in fact it’s experiencing a tremendous amount of stress-related excitement. Such excitement can easily teeter over into aggression.

An example is two hyper dogs in a dog park who chase each other to the point of exhaustion and roll each other. These often are the dogs that end up in skirmishes at some point during the play session.

A dog also may become reactive or hypervigilant in areas where fights occurred in the past. For instance, my German Shepherd becomes more reactive the closer we get to the baseball field near our house—the site of his last altercation two winters ago. As we approach the field he begins to pull on the leash and engages in frantic ground-sniffing (calming signal).

An owner can influence their dog's behavior by concentrating on their own behavior. Are there particular areas where you get stressed while walking your dog? Do you start to lose patience in specific areas when your dog becomes excited? Quite often our own behavior negatively effects our animal.

Pack Mentality Myth
There are some who place great emphasis on “pack mentality.” In order to fully understand what this terms means one must first learn a bit about canine social structures as it pertains to our pet dogs.

As a general rule, domestic or even feral dogs do not have complex social structures or hierarchies such as those observed in their wolf cousins. In observations of free roaming dogs—particularly in a 1989 study (Daniels and Bekoff) of over 154 free-roaming dogs in Newark, New Jersey, compelling evidence was revealed that these dogs lack any organized or complex social structures or leaders—or what some refer to as “pack mentality.”

The term pack mentality is a vague description that some use to describe leadership. The word mentality means “character or disposition,” so when someone in the training world uses the term pack mentality to describe how the dog interacts with humans, the term lacks any information pertaining to actual leadership skills and everything to do with personalities and overall emotional state of a group of dogs.

In my opinion, the term pack mentality means nothing unless you’re discussing a very specific group of dogs and you can somehow read the mind of each dog in that group to arrive at a conclusion on their intent or goals, disposition or character. What these individuals are trying to convey—and rather poorly—is the concept of leadership, which has nothing at all to do with disposition or character. A leader controls the good stuff.

Recently a woman asked me how could she go about teaching her dog to understand that her baby is the pack leader. Let’s see. Dogs don’t have complex pack structures, the child is not a dog, doesn’t look like a dog, smell like a dog, act like a dog, play like a dog, communicate like a dog, doesn’t compete for the same resources as a dog. When I asked to see how she was going about teaching it she poked the dog in the neck (for no reason).

This woman, along with countless others have been mislead by certain people in the training community who insist humans must act like a dog in order to convey the concept of leadership to their pet dogs. Complete hogwash!

Dogs perceive a leader as the person who controls all the good stuff—treats, food, toys, etc. Period. If you are looking to establish leadership you do so by controlling valued resources and having the dog work for them (reward-based training). You also establish leadership by setting up boundaries and rules. When you control the good stuff your dog will look to you for what happens next.

If you think you’re already an effective leader try this exercise: Ask your dog to sit for you as your friend takes the leash out of the closet. If your dog remains seated congratulations, your dog was trained exceptionally well. If your dog jumps up and runs to the person holding the leash you have just learned the power of controlling the good stuff.

In our homes there are many leaders and thusly, leadership roles change constantly. Depending on what time of day it is one leader may be switched with another. My husband is disabled and stays at home during the day. He sleeps in. I’m the one responsible for taking the dogs for walks and feeding them in the morning. For those two valued things I can get my dogs to do quantum physics if I wanted to. It doesn’t matter if my husband calls them to him, it doesn’t matter if he grabs a squeaker toy to distract them—they only have one goal: to get me to walk them and give them the good stuff.

When I leave, however, my husband controls the good stuff—games they play during the day, treats, etc. When I walk through the door at night leadership roles change again.

Role reversals and exchanges are also common among dogs living a feral life together, or domestic dogs who gather together in temporary groups. This is especially observable during play. Each dog takes a turn being dominant while the other is submissive. And such roles are continually exchanged during play.

Another pack mentality myth is that the pack leader walks in front. Really? It does?
Take any two dogs for a walk out at the same time and tell me if there is a strict protocol between the two regarding which dog is out front. There is none. No protocol exists in free-roaming dogs either. The concept that a dog has to walk on your left side and make eye contact with you (heel) was developed for the show ring and for schutzhund training (protection work) and its goal is to keep the dog from being distracted by its environment, not because it has a lower status.

The point of this section is if you want your dog to start paying close attention to you then start controlling all the good stuff, and stop giving it away for free. It doesn’t matter how many people in your home are perceived as leaders so long as your dog(s) understand that these individuals are the ones that make things happen.

Establishing leadership should never involve scaring your dog, hitting your dog, yelling at your dog or speaking to it in a deep growl-like voice—nooooooooo! It’s just controlling everything and offering wonderful things when it does something that pleases you that makes a great dog.

If the dog’s level of aggression has been escalating over time toward a particular size or color of dog and it begins bleeding out to other breeds there’s a pretty good chance the dog has begun the process of generalizing. Dogs are usually poor at making generalizations. But, when it comes to chaining events that involve fear they are very good at it. For example, a dog who was bitten in the past by a small white dog or had altercations with small light-colored breeds may begin reacting toward blowing white bags in the street.

Similarly, one who experienced multiple encounters on leash may begin to aggress toward strollers or other moving objects that appear to be connected to a human especially if those objects resemble the shape of a human and dog walking together.

Set Goals
Set realistic goals for your best friend. Establish short-, mid-, and long-range goals. For example, John wants Rover to play with familiar dogs. There’s a very good chance Rover may develop enough skills to play with familiar dogs, but that may not be feasible for two years or more.

Rover may first need to learn short-term goals such as walking calmly in the neighborhood without becoming hysterical when he sees another dog two blocks away (short-term goal); Then work toward the point where Rover learns to focus on his owner while they’re on a walk with  dogs present at a closer distance (mid-range goal); Then to teaching Rover how to come to his owner or walk away when he’s getting stressed (long-range goal).

Learn Dog Language/Practice New Skills
There is no miracle cure for dog-on-dog aggression. Working with such behaviors takes time. You will have to work toward very small victories and build upon those until larger victories can be achieved.

As far as I’m concerned, I feel learning canine body language is vital to success. I’m not saying you need to get a PhD in ethology, but learning some basic body language signals can go a long way in understanding the dog’s emotional state.

A professional dog trainer can help you learn such skills, or you can teach yourself by reading some books. At the end of this article I make book recommendations for that purpose.

Even though some dogs seem to spontaneously engage in fighting there are clear warning/calming signals they send out indicating it’s experiencing stress long before it reacts. Such signals may be as subtle as licking of the lips, yawning or sniffing the ground. Having knowledge of what to look for can arm you with precious knowledge that can go a long way in helping you to prevent encounters and rebuild some of the trust that may have been lacking in your relationship.

As far as being able to predict when your dog will react, it’s helpful to establish the dog’s threshold as a starting point for retraining. Threshold is the point of reactivity—the point where the dog reacts. When working with such cases it’s imperative to keep the dog below threshold at all times and systematically increase its tolerance to stressful stimuli.
As an owner you play a vital role in keeping your dog below threshold and you can achieve that goal be learning his body language.

Another way to keep the dog below threshold is to begin walking it at off-times—meaning times of the day when there is a lesser chance of running into other dogs and their owners. As the dog begins to experience uneventful walks it may begin to relax a bit.
Your trainer will teach you techniques on how to “get out of Dodge” quickly if you run into other dogs so you will want to set up training sessions at these off-hours and practice walk-aways, pair a pleasant stimulus to areas that may generate stress and more.

When you become more aware of your dog’s emotional state you may begin noticing stress signals in areas around your home.

My German Shepherd is dog-aggressive. To be honest, my big 120-lb boy is afraid of little dogs. Over the years him and I have become aces at reading each other. On walks he becomes a bit hypervigilant (overly alert) whenever we approach a particular baseball field near our home—the site of his last dog fight two winters ago. I know he’s becoming stressed because he starts licking his lips and yawning. So, to change his emotional state when we arrive he gets hot dogs. The baseball field starts to take on a whole new meaning. We also change direction if we see a dog approaching us.

Types of Training
Your trainer may choose many techniques while working with your dog. If they have experience with stressed dogs they most likely will rely on two powerful learning techniques—classical conditioning, which is pairing a pleasant experience/sensation with something fearful; and operant conditioning which is based on the concept that every action has a consequence. You must make every effort to ensure that your dog is trained positively. No scary stuff.

Scary stuff to me is harsh training methods that rely on leash corrections and physical punishments. Such methods often make aggression worse—especially if the behavior has its foundation in fear. Other scary stuff to avoid is flooding. Flooding is the term used to describe forcing an individual to face its fears until it surrenders. An example would be forcing a person who’s terrified of spiders to lay strapped to a table (no escape) as spiders are poured on top of them. They will panic, scream, fight, beg it to stop, cry, seem to give in then fight once more (extinction burst) until finally they shut down (learned helplessness) or they pass out. Flooding should never be used in fearful dogs.

Helpful Tips
The key to success in helping a dog-aggressive dog is multi-faceted and includes the ability to read canine body language, actively practicing avoidance techniques and working to change the dog’s emotional state as it relates to other dogs.

Before you engage in any training it’s vital to rely on an experienced professional for advice and guidance so you don’t make mistakes that can make the dog worse. You should look for an individual who understands the science of learning and behavior to teach you new skill sets that are based on positive methods.


HeadshotAugust.jpgKaren Fazio, PDT

