Aggression and Fear in Dogs

The number one reason people call a dog trainer or behaviour consultant is because of aggression issues with their dog.  Dog bites are on the rise and the media fans the flames, especially nowadays for certain breeds like the Pit Bull, the new 'craze' aggressive dog, along with the Doberman Pinscher, German Shepherd Dog, Rottweiler, etc.  Pages like this abound on the world wide web, so it is no wonder we're full of misinformation.

The first thing to understand about aggressive behaviour is that it's - complicated.  Aggression is "one of many social behaviours dogs use to communicate information to other dogs, animals, and humans" (Aloff, 2002).  It is communicative, and it is a sign given which conveys intent or purpose from the sender to the recipient.

If you are living with a dog who is displaying aggressive behaviour it's paramount that you contact a professional educated in, and experienced with, dogs who behave aggressively.

Ethologists and behaviourists have yet to agree on a specific definition of aggression, but here is a link to Dr. Roger Abrantes thoughts on the subject. Generally speaking, aggression has four parts:  The sender (the one displaying aggressive behaviour toward someone or something); a recipient or target of the action or behaviour; an observable action or behaviour; and a purpose/intention.

When assessing a dog displaying aggressive behaviour, we want to know who is the actor (sender)?  What do we know about this dog?  Who is the recipient or what is the target?  What is the focus of their behaviour?  What form does the behaviour take?  How can it be described cleanly and objectively?  What does the dog do?  What purpose does this behaviour serve?  What is it designed to do?

The last question is complicated and engages in a degree of speculation that should be aided by psychological, physiological and medical information.

The first step is to get a full medical exam and blood work done.

Teach your dog to love wearing a muzzle.  Another good resource for muzzles is the Muzzle Up Project website.

Be aware that when your dog is wearing a muzzle another dog approaching may have a hard time reading your dogs body language.  Normal signals dogs give to other dogs, like a tongue flick, may not be seen by the other dog because the muzzle distracts from the ability to see facial expressions and signals.

A growl can change in to a bite in a split second depending on the circumstances.  This can be due to trigger stacking.  Here is a video that explains it well, and here is another one.  Some dogs do not give any warning at all before landing a bite.

Here is a video on how to work with the fearful dog.  Note:  this is intended as general information, not necessarily intended for reactivity or a dog behaving aggressively - a professional should always be contacted as soon as you start to see any out of the ordinary behaviours.

Once common medical factors have been ruled out, our key question is about the dog in front of us.  Friedman (2017) states that behaviour is a combination of "genetic history, individual behavioural history, and current conditions". 

It can be a learned behaviour.  Somewhere, sometime the dog likely experienced something in its life that made it feel anxious, afraid, or not safe. Roger Abrantes tells us that the feeling of safety is more important, even over hunger and thirst.  Instinctually, when an animal feels these emotions the first response is to flee.  If the choice to flee was taken away from them, for example they were on the end of a leash and were prevented from running away, they may have tried another tactic, and that was to try to frighten off what they believed was a threat to them.  This is the flight or fight response.

In human and dog terms, fear is considered an emotion.  An emotion is a mental state that arises spontaneously rather than through conscious effort. Every animal experiences fear in the same way a human does - spontaneously and not under conscious control.

*Geek talk* Normally, when a person is in a serene, unstimulated state, the "firing" of neurons in the locus ceruleus is minimal. A novel stimulus, once perceived, is relayed from the sensory cortex of the brain through the thalamus to the brain stem. That route of signaling increases the rate of noradrenergic activity in the locus ceruleus, and the person becomes alert and attentive to the environment.

If a stimulus is perceived as a threat, a more intense and prolonged discharge of the locus ceruleus activates the sympathetic division of the autonomic nervous system (Thase & Howland, 1995). The activation of the sympathetic nervous system leads to the release of norepinephrine from nerve endings acting on the heart, blood vessels, respiratory centers, and other sites. The ensuing physiological changes constitute a major part of the acute stress response. The other major player in the acute stress response is the hypothalamic-pituitary-adrenal axis.

While roaming around the web looking for backup articles to add to this page, I ran across an article by someone claiming to be "The Canine Calmer". He presents a convincing arguement to never coddle or comfort a fearful dog and goes on to describe all sorts of things, like how would a mother dog treat its pup if it was fearful. He says that a mother dog or wolf would do nothing if the pup was afraid of something.  He states that a fearful pup would never even survive into adulthood.  "Fear is totally self consuming."  "Fear is anti-pack."  These ideas have been around for a long, long time and, as we can see, are still perpetuated today.

When we look at fear and aggressive behaviour from scientific, professional, reliable sources we learn that fear is not under conscious control.  The brain and nervous system act instanteously, and there is nothing we, nor our dogs, can do to change that.  It motivates us to protect ourselves, thus - aggressive behaviour pops up.

Fear is generally considered a reaction to something immediate that threatens our security or safety, such as being startled by someone suddenly jumping out at us from behind a bush.  It is alerting us to the possibility that our physical self might be harmed, which in turn motivates us to protect ourselves.  Thus, the notion of "fight or flight" is considered a fear response and describes the behaviour of various animals when they are threatened - either hanging around and fighting, or taking off in order to escape danger.  It has also been recognized that animals and people have other responses to a threat:  a person or animal might play dead or just "freeze" in response to being threatened; yell or scream as a fighting response rather than get physical; or, isolate as a flight response. (1)

Mostly what we see as "aggressive" behaviour in our dogs is the yelling and screaming as a fighting response rather than getting physical part.  If we do not understand, and respect, this communication the next thing that may happen is a bite.  It is extremely important to learn how to read dogs communication and body language to nip aggressive behaviour in the bud.  Dogs communicate using a complex language of body signals that reflect what they are thinking and feeling. They use these signals consciously and unconsciously to communicate intent and ensure their personal safety by affecting behavior in others.  Another resource to understand body language is:  Incredibly Detailed Charts Will Help You Speak Your Dog’s Language.  There are more resources on the Learning Resources page.

*Geek talk* The Fight Response in Dogs

As the term implies, this response depicts a defensive response from a dog who will use aggressive displays in hopes of removing the threatening stimulus.  Dogs may lunge, growl, snap and attempt to bite.  Examples include dogs who snap when they are cornered, dogs who lunge at other dogs, dogs who attack other animals they perceived as threatening.  

The fight response is also adaptive considering that it may be used when the animal cannot escape a confrontation and is forced to protect himself.

Fight or flight responses are as normal in our canine friends as in our human friends.  When you see a dog use a fight response such as a growl with a specific stimulus, consider if the dog has a good reason to do so.  Is the dog trapped?  Is this dog given a chance to use flight?  Could this dog have a good reason to not trust a particular stimuli? (2)

The worst thing you can do is to add a startle or correction to an already highly emotional situation.  The dog is already feeling fear and is in an emotional state.  Adding a leash pop, yelling at the dog, or worse, will only make the dog more fearful and can increase the aggressive behaviour.  Aversive and punitive actions will create anxiety in the dog, and the problem will get worse - not better.  Some "trainers" advocate this sort of action, and yes, sometimes smacking a dog will stop the aggressive activity, but - it does not change the underlying emotion, and that emotion may easily rear its ugly head again, and the response will likely be far worse than it was before.  This is precisely how you create a dangerous dog.

For instance, many dog trainers and behavior specialists agree that the indiscriminate use of aversives may be deleterious and may actually contribute to further behavior problems on top of the ones already being displayed. It is not casual, indeed that with the resurgence of the "dominance alpha wolf theory" fueled by Cesar Millans' National Geographic show the "Dog Whisperer" the number of dog bites are one the rise. Indeed, according to veterinarian and animal behaviorist Sophia Yin, dog behavior experts agree that dog owners who mimic what they see on television is one of the contributing factors for the 4.7 million dog bites that occur each year.

Once you identify a dog as being fearful or anxious, you should:

  1.  RESPECT their space: let them approach you (do not approach them).
  2. Do not attempt to pet the dog even if they do walk up to you.
  3. Make the experience rewarding.  The use of primary reinforcement in training is invaluable.  Toss high value treats on the ground:  don't attempt to hand a fearful dog food. (3)


(1) The Complexity of Fear, Mary C. Lamia, Ph.D

Dog's Fight or Flight and other Stress Responses

(2) Fight or Flight Response in Dogs?

Understanding the Dog Fight or Flight Response

A Guide to Dog Behavior Modification Techniques and Terms

(3) Flight or Fight! Fear Response in Dogs.