Excitement and Aggression

I am often called to consult on a particular type of canine aggression—an excited dog suddenly becomes aggressive and bites. To the people involved, it seems as if the bite comes “out of the blue.” However, the bite only seems surprising if we assume that dogs process excitement in the same way that people do. They don’t.  

From a human perspective, excitement reflects happiness, anticipation, and fun. However, for many dogs, and especially dominant dogs, excitement is much closer to anxiety and agitation than joy. The physiological and mental effects of excitement are almost identical to those experienced when the dog is under stress. 

Physically, excitement causes a dog’s body to decrease production of serotonin (a hormone vital to impulse control) and increase production of cortisol—also called the “stress hormone.” All dogs produce some cortisol all the time, as it functions in regulating energy and glucose levels. However, during a period of excitement, a dog’s cortisol production spikes, just as it would during a period of negative stress. While many factors contribute to the potential for aggressive behavior, research indicates that high levels of cortisol correlate to increased aggression. The concurrent serotonin deficit impairs impulse control, making aggression even more likely—especially aggression that occurs without the usual warning signs.1 

Mentally, dogs crave predictability and order. Some dogs become overwhelmed in situations where the energy and activity seem out of control. A submissive dog may respond by retreating or by peeing on the floor. A dominant dog, however, responds by trying to control the situation and all its participants, including you. If things are out of control, he will try to take control—by force if necessary.  

Excitement aggression is particularly dangerous because an excited dog often does not show any of the usual warning signs such as snarling or stiffening his body before he bites. And, because excitement looks to us like happy exuberance, we aren’t expecting aggression and may miss any subtle clues the dog does give that aggression is coming. To be safe, take steps to prevent being taken off guard by excitement aggression.  

  • Don’t purposely encourage excitement in your dog. 
  • Avoid including your dog in situations that could generate too much excitement. 
  • Be alert for triggers that escalate your dog’s excitement level. 

Most importantly, if your dog has shown any signs of aggression, consult a professional trainer. A trainer can teach you how to correct and control your dog safely, thereby minimizing the chances of injury to you or anyone else. 

Greeting Calmly 

One of the most common scenarios in which people build up excitement is when they are greeting their dog or introducing someone to their dog. When we raise the excitement level around a greeting it says to the dog “This is HUGE! This is UNIQUE! Who KNOWS what will happen next?” Some dogs just can’t handle the excitement. They are confused about why we are making such a fuss over a simple greeting—an event dogs usually handle with a cursory butt-sniffing.  A dominant dog will often snap or bite in a misguided—and aggressive—attempt to stop the madness.   

Other dogs may initially respond with jumping or mouthing. While these behaviors are not overtly aggressive, they should be discouraged because they can cause accidental injury. In addition, these behaviors increase the excitement level all around, initiating the systemic changes that can escalate to the point of aggression. 

When dealing with a puppy or an adult dog, it is extremely important not to build up the excitement level when greeting.  

  • Stay calm and use a normal tone of voice.  
  • Allow the dog to smell you and calmly gather some information before you reach toward him with your hand.  
  • Do not bend directly over the dog’s head. A fearful or aggressive dog will feel threatened or challenged, and even a non-aggressive dog can give you a concussive head shot if he jumps up while you are bending down.  
  • Pet him calmly and soothingly.  
  • Do not make a big deal over the fact that you have just walked in the door. You want your dog to view your comings and goings as a matter of routine.  

Dogs Are Not People 

An illustration of the difference between the canine and human experience of excitement is the arrival of guests. To us, it’s exciting because we anticipate an evening of fun. However, from a dog’s perspective, a lot of stressful things are happening.  People’s voices get louder, “outsiders” are “inside” their territory, and there is a lot of physical contact and activity. From your dog’s point of view, no one seems to be in charge. In the midst of all this chaos, his stress hormones are through the roof and his impulse control is tenuous. Why are we surprised when this excitement causes the dog to snap?  

Playing Appropriately 

Another instance in which too much excitement can build up is during playtime. Playtime should not be a free for all.  Just as games have rules, your playtime with your dog should have parameters that your dog understands and respects.  

  • Do not allow your dog to jump on you, mouth your arm, or nip you during play. 
  • Don’t let your dog get so rambunctious that he is unable to rein himself in when you give a command.   
  • Have a clear command that signals the end of any game. 
  • Avoid games that put your dog in competition with you, such as tug-of-war. The hormonal shifts caused by the excitement of the game, combined with your dog’s predisposition for control, can transform a playful struggle for dominance into a real struggle, which your dog may attempt to win with his teeth.  
  • Dominant dogs that become too excited do not belong in dog parks. Being around other dogs barking and chasing one another will almost certainly trigger the aggressive urge to control the situation. In fact, I am not a fan of dog parks for any dogs. You have no way of knowing how well other people can control their dogs or what the temperament and health of the other dogs is. 

Being One Step Ahead of Your Canine Partner 

The good news is, you can stay one step ahead of your canine partner. Because you know what precipitates the excitement, you can avoid contributing to it.  Also, you can be prepared with a game plan to short-circuit any out of control behavior.  

Don’t ask questionsWhy do we ask our dogs if they want to go out? Canines don’t debate or discuss walking. The leader decides when the group will move; the others follow. It’s that simple. Asking your dog if he wants to go out just gets him excited and frantic. At the very least, encouraging excitement before the walk makes it difficult for you to put the collar and leash on your dog. Worse yet, if your dog has a tendency for excitement aggression, you are creating the perfect circumstances for a bite.  Keep your dog calm before a walk by being a calm leader. When it is time for a walk, call your dog to you; put on his collar and leash; tell him to heel; and walk out the door.  

Similarly, asking your dog “Do you want a cookie?” or “Are you hungry?” does not give him an enjoyable sense of anticipation, but rather a sense of excited frustration. His frantic body language is saying, “Of course I want it! Why are you still talking? GIVE ME THE TREAT NOW!!!”  As his excitement grows, so do his frustration and his need to control the situation. Stress rises and impulse control goes out the window. Suddenly, using his teeth to hurry you along seems like a good idea to him.  Don’t ask your dog if he wants something before giving it to him. The only thing that should precede giving your dog a treat or his food is obedience.  

Replace excitement with obedience. To be fair, even when people don’t verbally communicate what’s coming up, their dogs often sense it and become excited. Your dog may sometimes seem “pyscho,” but he probably isn’t psychic. More likely, he has learned to recognize the routine that signals you will be taking him for a walk or feeding him. Make obedience part of that routine. Before your dog can pick up any signals, make sure he is wearing his training collar and leash. Then, before you put on your coat for a walk or pick up the bowl to feed your dog, give him a command to sit or down. If, in his excitement, he disobeys the command or breaks the command before you release him, correct him. Until your dog learns to respond more calmly to the cues, you may have to keep his collar and leash on all the time when you are at home. Whenever you see your dog start to get excited, give him a command to sit or down.  If he continues his excited behavior, correct him for not complying with your command. This makes clear to your dog that he is being corrected for disobedience, not for being excited. 

Watch for triggers. Even without your input, there may be some events and circumstances that trigger excitement in your dog.  Your dog may become overexcited when he sees other people or dogs while you are out walking. Some dogs are triggered by noisy or fast vehicles passing by.  When you are out and about with your dog, he should walk in heel. Be alert for triggers that will cause excitement.  Before your dog can react, reinforce the heel command and get his focus on you.  If he does not obey, correct him.  
Be alert for triggers that set your dog off at home as well. If the mail delivery creates a frenzy each day, schedule a little training practice to begin just before the mail carrier’s usual arrival time.  If your dog is working with you, he cannot work himself into an overexcited state. 
Don’t expect miracles. It will take time before your dog is able to control his response reliably. Use praise to reinforce good behavior, but don’t praise so energetically that you initiate an excited response. The key is to be insistent that your dog obeys the commands, consistent in correcting disobedience, and persistent over time.   

Accept reality. If your dog has already shown aggression when excited, you cannot take any chances. You must accept that your dog will always need some limitations on how, when, and if he can interact with people and other animals. Do not place your dog in situations that increase his excitement and stress.  

  • If visitors are coming to your home, crate or kennel your dog in a separate area, away from the action.   
  • If you are out in public with your dog and see his excitement level escalating, remove your dog from the situation calmly, but firmly, with obedience commands.  
  • Never allow strangers to pet your dog.   

Your dog will have to be involved in a training program most of his life. This problem never goes away completely. If you relax your training, your dog will begin to test you.  You and your trainer will determine the type and frequency of training needed to ensure you stay on top of the situation and recognize setbacks or improvements.  

You can’t change temperament. Although effective training can change your dog’s behavior, it cannot change his temperament. If he has even a slightly aggressive temperament, then encouraging or allowing excitement increases the likelihood of a bite. You have no room for error with a dog that bites. Most likely, your dog will always have to be closely supervised around other people and animals because to your dog, they are inherently exciting. Unless your trainer advises otherwise, do not give your dog second chances to interact with others. Every “second chance” to interact is a “second chance” to injure someone. In addition, every bite puts your dog in increasing danger of being removed from your home and/or euthanized because of his aggressive behavior. 


Excitement aggression is, unfortunately, a problem that is never completely solved. However, with proper training and some common sense, it is a problem that can be effectively and safely managed. By limiting excitement, anticipating triggers, and using training to modify your dog’s response to exciting stimuli, you can minimize the chances that your dog will have the impulse or the opportunity to bite.   

The consequences of getting the training wrong are significant and sometimes irreparable. For this reason, you must get some professional training to ensure you do not make mistakes that exacerbate the problem. A professional trainer can teach you techniques, recommend a game plan, and help you identify the necessary precautions. These tools are useless, however, unless you use them. Ultimately, you are responsible for implementing the techniques, the plan, and the precautions so that you and your dog can share a calm, happy, and safe life together.  

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