According to the latest studies, there are at least 25 motor patterns of aggression in dogs, influenced by genes. But what exactly is aggression ? It's a threat or physical act against an individual's physical or psychological equilibrium. By this we mean any behavior that results in forcing another individual to remain at a distance, either spatially or socially, but without necessarily resulting in physical harm. Aggression does not necessarily mean "danger", but rather an estimate.

In this chapter, we'll be focusing on domestic dogs. As we shall see below, they are responsible for the greatest number of aggressions and bites in Switzerland, and quite logically, since dogs are all around us. Documentation and descriptions have therefore mainly been drawn up with the dog in mind, although they are still valid for all other canids.

Aggression stems from genetic factors (the animal and its ancestors) as well as epigenetic factors such as the repercussions of pregnancy, primary socialization (the first three months) and secondary socialization (beyond 3 months), the education given by the mother & other adult congeners, the environment provided by the breeder & owner, incidents/accidents in daily life, positive and negative social encounters, illnesses, etc. It therefore has multiple origins which can predispose certain dogs to be aggressive, make aggressiveness appear or aggravate it. It's important to remember that, depending on the circumstances and many other factors mentioned earlier in this dossier, any animal can represent a danger, aggressing defensively or offensively. If you want a 100% guarantee that a dog will never bite, then you have to make an irrevocable decision to choose...a plush dog ! It's vital to get it out of your head that your dog will never bite - nothing could be further from the truth, and nothing could be more dangerous !

As far as the canine is concerned, he has no choice but to use his motor patterns, genetically programmed for dogs and prey, towards humans. It cannot invent or learn a new language, independent of his intrinsic motor patterns, to communicate with humans (J. Dehasse).

There are two types of aggression towards humans :

- defensive/reactive : the canine reacts when the person moves towards him.
- offensive/proactive : the canine moves towards the person to attack. For wild predators, this is called a predatory attack.

According to the evaluation of dog and wolf attacks (OSAV/NINA report), the vast majority are defensive. This clearly demonstrates the canid's "non-conflict" stance, as he doesn't see human as prey first and foremost. But as mentioned above, the canine remains a predator, and offensive aggression or predatory attack is also possible, in specific circumstances. 

In terms of aggression, we can also mention that there are three categories for assessing it :

- Predictable aggression --> the canine emits a phase of identifiable (facial expressions, postures, vocalize ) and comprehensible threats.
- Less predictable aggression --> the threat phase is difficult to identify or is almost simultaneous with the attack.
- Unpredictable aggression --> the attack is immediate, with no prior warning.

Any canid, in a situation of discomfort, fear or surprise (unexpected and close encounters with humans for wolves), finds himself in a defensive position. If the so-called "safety distance" is very short, he will show clear and identifiable signs :

- Ears back
- Mydriasis (dilated pupils)
- Wrinkling of forehead and muzzle (curling up and uncovering the whisker pads)
- Herringbone on nape of neck and dorsal spine
- Tail between hind legs
- Small C-shaped jaw (or large C in case of offensive aggression) showing teeth
- Grunting
 
These signs indicate to the person/congener that the individual is in a very uncomfortable situation, that he is uncomfortable or afraid and that the action in progress must be stopped immediately. Walking, approaching, petting, trying to take the bowl, the human must stop short and leave the animal alone.

The growl, often seen as a sign of behavioral deviance or aggressiveness by those who doesn't know much about the canine behaviour, is nothing more than the last warning given by dogs/wolves to signify the same state of unease, which arises when the previous signals have not been understood or ignored. It's part of the canid's accoustic communication. In the wolves, this growl occurs when there is a surprise effect and the distance separating them from what they consider to be a danger to their physical integrity is short. It's important to remember, however, that growling doesn't necessarily lead to biting, as long as the person immediately stops the action in progress and gently backs away from the canine (set back the distance). It's a warning sound that must be respected but not misinterpreted.

With canids, in the case of defensive attacks, signals are very often given before the bite. But in certain cases, where a canid's instincts are stimulated, such as when a jogger, trailer or cyclist passes by, the aggression will be immediate and without warning signs. Unfortunately, this is what we shall call "prey play", since a fast-moving person, animal or thing that runs or flees awakens the canine's predatory instinct, and dogs/wolves set off in pursuit. We would like to remind you that an instinct cannot be modified and is specific to the species, so in the presence of dogs or wolves, it is essential to stop running/cycling, walk (beside the bike for cyclists) and not set off again until the animal is out of sight.

But in specific circumstances, such as unpredictable attacks, canids may give little or no warning. This can vary from one individual to another, depending on many factors such as the behavioral and physical changes discussed above, or pathological disorders (hyperreactivity, hypervigilance, OCD, senile dementia), among others. It's also worth mentioning that reactions will depend, once again, on many factors such as genetics, epigenetics, circumstances, situation, current emotional/physiological state, but also on the individual's personality and character, which are specific to each individual (as for every living being). We should never forget this. 

In dogs, there are four phases/sequences of the act of aggression :

1) Intimidation phase (threat)
2) Attack phase (action/bite)
3) End phase (appeasement)
4) Refractory phase (ceases and does not return unless the threat continues)

There's a little-known fact about dogs that's vital to integrate : as soon as an individual is confronted with a disruptive element (strong excitement or frustration), this will generate an emotion that's very difficult for him to manage. The only way to calm down and return to a normal state is to...bite ! He'll turn to anything nearby, whether a toy, a fellow dog or a human. This is the cause of the famous "redirected aggression". It's unfortunate that canine communication patterns, all the signals of appeasement but also those indicating discomfort, fear or stress, are not known or mastered by every owner and, beyond that, by the population in a more general sense.

There are several types of aggression in canines : parental (weaning, disciplinary and educational), competitive/social, sexual control, irritation (frustration, pain), maternal (protection), space defense (distancing, group defense, territorial), redirected, pursuit and pack (infanticide, group predation).

After reading the previous paragraphs, it's very important to learn how a canid works, through his mimics, postures, instincts, behaviour and communication. By understanding our own dog, we can spot the signs and, with the help of a professional dog trainer or veterinary behaviorist, understand the causes and remedy them wherever possible. 

There are several types of canine bite :

- Single bite                   The dog bites once and releases.
- Single bite and hold    The dog bites once but does not release.
- Multiple bites              The dog bites several times, releasing each time.    
- Multiple bites/hold     The dog bites repeatedly, does not release, shaking his mouth, causing muscles to tear.
                     
To understand the possible physical consequences of a bite, you need to know that the power of a canine's jaw oscillates between 100 and 150kg/cm2. However, it can reach 700kg/cm2 for a Kangal, one of the largest dog breeds. The wolf, on the other hand, is 150kg/cm2.

To conclude this chapter, we turn to appeasement signals, practiced by all canines. These are preventive behaviors applied to prevent conflict. They are used at an early stage to avoid escalating situations that could degenerate and seriously damage the integrity of individuals. Their aim is to calm oneself and the other person, with a dual effect. It should be noted that they are genetic, the yawn being the very first acquired at birth.

Here are a few of the canine's signals to help you understand him better :

- Looking away                            
- Yawning                                                    
- Lowering the head                                              
- Licking nose                                         
- Lie down                                                     
- Show flanks (T position)                   
- Stop all movement (freezing)
- Scratching
- Raise paw
- Lower ears
- Tail wagging
- Walk in an arc

Vocalizations are also used to soothe and communicate :

High : they express a complaint (pain, fear, need for help).
Normal (yo-yo) : they refer to everything that's cool (games).
Low : they express a threat, an aggression.

To appease a canine, we can also use soothing signals such as :

- looking and then looking away (with a slight turn of the head)
- walking in an arc (rounding off to approach a dog, i.e. not coming straight at it)
- yawning, ignoring the individual
- walking slowly  

As far as wolves are concerned, the chapter on "wolf attacks on humans" will provide you with detailed answers.

We hope we've been able to provide you with a few explanations of the different types of aggression associated with canids. Knowing and understanding how they work not only helps to avoid many incidents, but also enables you to communicate better with your dog, which is highly beneficial to his quality of life. 

For those interested in finding out more about canine behavior, aggression and genetics, there's a very comprehensive and interesting book called "Tout sur le comportement du chien" ("all about dog behaviour, only in french), by Joël Dehasse, a leading veterinary behaviorist and recognized authority in his profession. Michel Georgel's "Éthologie du loup, éthologie du chien" is also well worth a read.

Dictionary

Motor pattern       Innate sequence of genetically programmed behaviors (sequences of a behavior).
Intrinsic               Inherent in someone or something, belonging to it.
Pathology             Disorder, disease.
Pathological          Pertaining to a disease or disorder.
Deviance              Character of something that deviates from the norm.
Genetic                Everything relating to genes, heredity.
Epigenetic            Everything that comes from parents' upbringing, learning and experiences throughout an individual's life, whether positive or negative. 
Hyperreactivity     Excessive reactivity or reaction to an external stimulus.
Hypervigilance      State of alertness abnormally exacerbated by the anticipation of imminent danger, real or imagined, and accompanied by heightened anxiety.

Photos : Illustration, FSIFP, D. Mech, J. Dehasse

NEXT CHAPTER : WOLF ATTACKS ON HUMANS (2002-2020)