For most human minds it might be inconceivable, but aggression in dogs is actually considered— to some extent of course— a normal canine behaviour.
If we look at a definition of aggression, it may be defined as any threat or harmful behaviour which is directed towards another individual or group. Aggression is a strong violent reaction to a perceived external threat. Generally it can be said that essentially all aggression is born out of some kind of fear.
Just like humans, dogs have four basic natural responses to fear: fight, flight, freeze and fawn. Aggression is the manifestation of the fight response. Fearful dogs cannot discern between an actual threat and a perceived threat, which makes it for dog owners sometimes very difficult to understand the underlying triggers which cause their dog to act in an uncontrolled and aggressive manner.
Aggression in dogs doesn’t necessarily just mean that the dog actually bites, but can include a lot lesser degrees starting from „grumbling“, growling, snarling to showing teeth, up to snapping in the air without actually biting.
But why do our beloved furry friends resort in certain situations to aggressive behaviour? Can’t Fluffy just be chilled and enjoy his life in harmony with the other dogs at the dog park? What did the mailman do to upset him so much that he welcomes him every morning in berserk attack mode? Often the answer is not a simple one and consists of complex factors coming together.
It’s important to understand that in the canine world aggression is the outward expression of certain emotions and is used to communicate various intentions by a dog. Aggression is just one option of a whole range of behaviours which dogs have available to deal with unfolding events as part of their daily life’s challenges.
No dog resorts to aggressive behaviour without good reason and even there are a whole number of triggers which cause a dog to resort to violence, it is almost invariably linked to some form of real or perceived threat. In theory, even the most mellow dog, if pushed just far enough can and will use some form of aggression in order to stop the threat.
Aggression: Just a case of bad parenting?
Unfortunately not all dogs have grown up in a perfect puppyhood and have been exposed to situations in which they learned that aggression can solve problems for them and thus, for some dogs, it became the first choice to solve problems. Humans easily label those dogs as kind of „naturally aggressive“ but they actually just respond to the conditioning they have picked up in their learning experience while growing up.
But even a dog has had a balanced and happy childhood, it will still use a certain degree of aggression which it feels is appropriate in a given situation. What appropriate means for the dog depends a lot on what they have learned previously and also depends on factors like breed, health, past socialisation and the environment they live in.
Body signals – Will you just f*** off!
Its extremely unlikely that a dog will immediately resort to the highest level of aggression – going for the kill bite – without having first communicated certain non-aggressive signals and postures to signal that they want the other one to stop whatever it is that they do not like. But it can sometimes just be milliseconds between sending out a warning signal and a bite.
Those „calming signals“ or „threat reduction signals“ show that they are uncomfortable in a given situation and do not want to escalate the situation if the other one does the right thing in their eyes and just buggers off. It often starts with the dog becoming very still and its body rigid. Sometimes dogs send out signals like yawning, licking their nose, turning their head or body away from the perceived threat, avoiding eye contact by squinting, flattening their ears tightly to the head or can even lead to mouthing or what is called a „muzzle punch“, when a dog literally punches another dog or a human with its nose. But of course dogs don’t always follow this escalating sequence and often display several behaviour simultaneously.
If the other dog or a potential human threat does not back off, then dogs quickly resort to more threatening signals higher up on the ladder of aggression like baring their teeth, narrow the eyes and raise hairs on their back. They begin to growl and snarl, shift their weight to allow for a possible escape, let out sharp barks or snap in the air. If all those threatening signals don’t work to ward off danger, then it is often unavoidable that the dog will use brutal force, which inevitably leads to a quick nip that leaves no mark, to bites which cause bruises or bites which puncture the skin. The ultimate aggression level is reached when the dogs bites repeatedly in rapid succession and even shakes its head to break the neck of its victim. No need to mention that this inflicts severe injuries.
Dogs are usually experts in reading another dogs body language and can perfectly judge the threat level of its opponent, unlike most humans can. People often don’t understand the warning signals, which dogs send out to actually calm down or diffuse a certain situation or they just don’t pay much attention to them. Overtime some dogs learn that the subtle gestures they are sending out just don’t work with humans and go straight to the more obvious ones and bite.
Some people think that dogs are just born mean and therefore aggressive, but that’s entirely wrong. Aggressive dogs become that way through a complex interaction of many factors of which the majority are beyond the dog’s control.