First Things First
Before we can discuss a method for treating aggressive behaviour in dogs, we have to understand one core concept: "aggressive" is how we describe behaviours such as snarling, growling, lunging or biting. It is not a core personality trait of a dog. Your dog is not aggressive, they are displaying aggressive behaviour. When we remove the label, we can see things more clearly.
Any individual is capable of displaying aggressive behaviour and whether these behaviours are witnessed is a combination of genetics, life experience, learning history, environment and breakdowns in communication.
What's the Function?
The first thing we need to consider when training a dog to decrease aggressive behaviour is the function of the behaviour. This is a scientific way of asking what outcome your dog is trying to achieve with the aggressive behaviour. All behaviour occurs for some reason, and aggression is no different. For most dogs who display aggressive behaviour, the function is to create more space.
Here's are a few examples.
Example 1: Robbie the Border Collie is unsure of new people. During a holiday party, the family invites many family and friends who Robbie has never met before into the home. Robbie avoids the new people, tucks his tail and looks to his family for help. Despite his fearful body language, strangers continue to pet him and cuddle him. He growls a few times but is told to knock it off. Finally, he's had enough. He bites.
Robbie is not an "aggressive dog". Robbie is a dog who has displayed aggressive behaviour. The function of Robbie's behaviour is to put more space between him and the strangers.
Example 2: Kiko the chihuahua is sitting in her mom's lap. Mom loves to hug and kiss Kiko.
The first couple of times this happens, Kiko stiffens, licks her lips and tries to move her head away to communicate her discomfort. Mom doesn't catch on and continues to kiss Kiko. Kiko has reached her limit. She bites mom in the face. The function of Kiko's behaviour is to get mom to stop kissing her.
Stopping the Aggression in the Short-Term
The first step for a dog with a history of aggressive behaviour is to stop putting them in situations where they feel the need to behave aggressively. For Robbie, this might mean not having visitors over for a while, or creating a safe space for him to retreat to and asking visitors to refrain from petting him. For Kiko, this might mean finding ways to show affection without kissing or hugging.
Understanding Body Language
We will not successfully improve aggressive behaviour if we don't understand the beginning signs that our dog is becoming uncomfortable. When we don't catch on and intervene in early signs of discomfort, we find ourself always playing damage control when the dog has escalated to growling or biting.
Changing The Aggressive Behaviour
The first thing we should consider is whether we need to change the behaviour in the first place. For a dog like Robbie, the answer is probaby yes. We want to be able to have visitors to our home without fear of a bite and we want Robbie to be more comfortable around new people.
For a dog like Kiko, let's consider our options. We could just not hug or kiss Kiko and accept that most dogs do not enjoy this type of affection. Or we could work on helping Kiko feel better about hugging and kissing. In Kiko's case, I would lean toward skipping the kisses.
So how do we change aggressive behaviour? Once we know why the dog is behaving aggressively, we want to improve the underlying emotional response that is causing the aggression, starting with the easiest version of the problem scenario. For Robbie, visitors coming into the house is very difficult, so let's start outside, in a neutral area away from home.
Let's train Robbie that when strangers are around, cheese rains from the sky. Let's keep the stranger at a distance where Robbie feels safe and slowly bring them closer as he progresses. Robbie is starting to think that maybe having strangers around is not so bad. Once Robbie is happy to have a stranger around outside in that neutral area, we can move our training to his home base.
Don't we need to correct the dog so they know aggression is not okay?
No, we don't need to correct the dog. Why?
The behaviour is a symptom of an underlying emotion, not a bad behaviour your dog is doing on purpose
Correcting aggressive behaviour suppresses the behaviour itself without treating the root cause of the behaviour. This means the discomfort is still there, but your dog is unable to express it. This makes it more likely that your dog will bite without warning next time (because we've told them it's not okay to warn).
Using corrections in training weakens the bond between you and your dog and gives them an icky feeling about training
Correcting a dog when they see the thing they don't like will make them like it even less
A Note About the Vet
When aggressive behaviour occurs, a vet check should be a requisite part of your process. This is because underlying pain or discomfort is a leading cause for aggressive behaviour (I would be more cranky if I were in pain, wouldn't you?)
Another reason to visit your vet is to discuss underlying mental health conditions that could be exacerbating the problem. A trip to a veterinary behaviourist may also be in order to get to the root cause of the problem and treat it holistically.
Tess Morgan is a dog trainer in London, Ontario. She offers sessions in London and online to help families with reactive, aggressive, fearful and anxious dogs.