Reactivity to other dogs, people, cars and bikes when out walking is becoming a more common issue for guardians these days, which in a nutshell is largely to do with how our lives and the world has changed over the last 30 years. So many people must now walk their dogs late at night to avoid going through the extreme stress we feel when our dogs aggress and start lunging, growling or barking at the end of the lead, not to mention the judgment from other people. 

Aggression, however, is an emotional response with a function – to attempt to control the situation when faced with the uncertainty of perceived danger, with the purpose of avoiding injury. Basically, they are very afraid and want the ‘thing’ to go away so that they can feel safe again. 

When a dog’s fear threshold is surpassed, the nervous system takes over, inhibiting the cerebral cortex (high cognitive function and learning) and creates a brain bath of chemicals including adrenaline, cortisol and endorphins, which means they can no longer hear, think, or respond to cues. Its why they never ‘listen’ when we try to intervene, they physically cannot process what we are asking, let alone hear us in that moment. They are merely panicking/reacting. They don’t choose to experience this chemistry; it just happens and is dependent on the individual’s threshold when something is deemed scary enough to cause an intense negative emotional response. Dogs that haven’t had any or little training are subject to much lower thresholds for stress than dogs that have been educated, thus are more prone to fear based reactivity. 

But why react that way, it’s just another dog/person, etc? Negativity Bias is a term meaning that even low or moderate concern/negativity perceived by the brain will be responded to with much more intensity than equally intense positive things.  This is a primal survival mechanism because ignoring any potential threat could lead to death, but ignoring a pleasant thing merely leads to a missed opportunity for fun. 

Aggressive behaviour at the end of the lead is highly reinforced. They can learn that their reaction makes the ‘scary thing’ go away, because from their perspective, that’s how it seems. They do not know the scary thing was going to go away anyway, they simply associate their reaction with it going away. The chemicals that flood their brain when they aggress can become addictive, and learning the behaviour ‘works’ means there are both internal and external reinforcers at work, its why this behaviour does not go away without intervention, and often gets gradually worse. 

The most important thing with aggression and reactivity is to avoid all and any repetition of it, because the more they do it, the more hard wired it becomes and the harder it is to ‘re-wire’ their brains. The other factor at play is that with each instance of fear, the dog collects more data in that moment to associate with the original thing that caused the response, leading to fear of more and more things. For example, if the reactivity started when passing just one particular local dog, then one day the guardian appeared with said dog, but also holding an umbrella, the umbrella may now become part of the picture when the negative emotional response is triggered, so the next random person walking a dog with an umbrella may well trigger the negative emotional state again. It’s then possible that the umbrella on its own becomes associated as a source of fear, meaning that it’s not just dogs that cause the reaction now, but anyone with or without a dog, walking under an umbrella. One day someone passes with an umbrella over a pram, we can now add prams to the list and so forth. 

When it comes to reactivity therefore, we must avoid all situations that cause the behaviour, and seek help, otherwise it will likely snowball to the point that the dog eventually experiences negative emotions in response to a whole list of outside ‘things’, and ultimately becomes too afraid of the outside environment to enjoy being walked. 

If you have had trainers in the past that didn’t resolve this issue, it’s likely because they did not have an adequate understanding of the dog's mind, and simply tried to stop the behaviour itself, not address the reason for it.  Lead corrections, punishment, or aversive methods will NEVER cure fear, it only makes it worse. Reactive dogs need compassion, and therapy to help them through their fears. There is no quick fix when it comes to an emotional nervous system response caused by something perceived as danger. If we were terrified of spiders, no amount of shouting, pain or punishment would change that, we would still FEEL the same, but we’d simply learn to hide how we felt to avoid the pain that follows if we didn’t. What more, how would we feel about the person inflicting the pain? Aversive techniques severely damage our relationship with our dogs and are unethical.  We help fear-aggressive dogs by using positive reinforcement to help them realise there is nothing TO fear, and that must include us, this is what ‘stops’ the behaviour, there is no other way.