Reactivity as a Symptom, Not a Diagnosis: Why a Plastic Bag Can Trigger an Avalanche

“Fear is the enemy of learning. It is the negator of joy, the preventer of play, and the inhibitor of trust and love.” — Karen Pryor

In the cynological world, the term “reactivity” has become a sort of universal label for everything undesirable—from barking at the postman to lunging at other dogs. However, viewing reactivity in this way is a fundamental mistake. Reactivity is, in fact, merely a visible symptom of deeper processes in the dog’s mind.

The Myth of Dominance and Aggression: What Science Tells Us 

One of the most persistent myths is that a reactive dog is trying to “dominate.” Roger Abrantes, one of the greatest ethological authorities, clearly defines dominance as situational behavior aimed at gaining access to a resource without injury. If a fight or injury occurs, it is not dominance, but aggression. 

Konrad Lorenz, in his work On Aggression, reminds us that aggression is a natural instinct necessary for survival and the formation of social bonds. The problem arises when the natural social structure is disrupted—for example, by leash restriction, which prevents the dog from escaping and forces it into “fight” as the only defensive strategy. 

What is Reactivity in Reality? 

The word “reactivity” is somewhat overused in today’s cynology, and most people automatically imagine a dog aggressively attacking other dogs. In reality, however, it is any exaggerated or inadequate response to an external stimulus. Reactivity is essentially anything the dog evaluates as significant and fails to respond to with calm—from a person in a hat to a plastic bag fluttering in the grass. The essence is that reactivity far from represents only conflict behavior toward other dogs, as is commonly believed. It is an umbrella term for situations where the dog evaluates the environment as unmanageable and responds with an excessive emotional reaction, whether it be barking, lunging, or conversely, “freezing” and avoidance behavior.   

Anatomy of Reactive Behavior: From Excitation to Explosion 

A key element that distinguishes a reactive dog from an aggressive one is often the absence of intent to cause harm; a reactive dog is primarily trying to relieve its internal tension or increase the distance from a stress source.

Physiological Mechanisms and the Role of Arousal 

Behind every reactive episode lies a state of high internal tension called arousal. At this moment, the so-called sympathetic nervous system is activated in the dog’s body—a kind of internal “standby mode” that prepares the organism for immediate action. Stress hormones, particularly adrenaline and cortisol, are rapidly released into the blood, commanding the dog to instinctive reactions of the “fight, flight, or freeze” type.

The turning point is the so-called reactivity threshold. It is an invisible boundary beyond which the dog stops handling the situation calmly. If the dog crosses it, its brain literally switches from “thinking” mode to “reacting” mode. In this phase, cognitive thinking and logical reasoning are practically out of operation. The dog’s reflex arc is so burdened at that moment that the dog is unable to perceive you calling its name or learned commands; its entire attention is consumed by the stimulus that caused this state. Below this threshold, the dog is able to cooperate with the handler, perceive the surroundings, and learn; above it, however, the cognitive component of the brain is “switched off,” and any attempt at training at that second misses the mark.   

Why Even a Plastic Bag Can Trigger an Avalanche?

 The phenomenon known as “trigger stacking” explains why a dog sometimes reacts explosively to a stimulus it ignores at other times. Imagine it as a metaphorical cup: every stressful or exciting event during the day pours a little “liquid” in the form of stress hormones into it. If the dog does not have enough time for deep rest and calming so that cortisol levels return to normal, its nervous system remains in constant tension.

In such a state, even an absolute trifle—for example, the aforementioned plastic bag—is enough for the cup to overflow, triggering a massive reactive explosion. The dog at that moment is not responding only to that one bag, but to the sum of all stressors that have accumulated in it throughout the day.

Debunking Myths: Dominance, Disobedience, and Passivity

The Myth of Dominance 

❌ Myth: A dog’s reactive behavior is a manifestation of its effort for dominance and gaining an “alpha” position. 

🟢 Reality: Dominance is not an innate personality trait of a dog, but a situational and dynamic relationship regarding access to a specific resource. It is behavior aimed at gaining access to a resource without injury. A reactive outburst is thus not a power struggle, but a manifestation of internal tension that the dog cannot solve otherwise at that moment.

The Myth of Disobedience and Punishment

 ❌ Myth: Outbursts on the leash are a manifestation of intentional disobedience or aggression that we must suppress by force. 

🟢 Reality: Outbursts on the leash are a symptom of high internal tension. The dog, due to stress, temporarily loses the ability to self-regulate and has not yet been taught how to constructively process this state at that moment. Physical corrections on a dog under the influence of fear or stress accelerate the entire situation and deepen its internal anxiety and stress, confirming that the surroundings represent a threat.

The Myth of Avoidance (Passive Approach) 

❌ Myth: The only way is to avoid triggers, passively lure the dog away, and thus “solve” the situation for it. 

🟢 Reality: By this approach, we may protect the dog in that moment, but we do not teach it its own self-control. Our goal is not just to “survive” situations, but to equip the dog with skills that allow it to go through demanding moments with minimal emotional exertion and stress, to maintain internal calm and the ability to self-regulate even in a busy environment.

From Reactivity to Activity: How We Transform the Dog’s Internal World in Training 

We do not solve only what the dog DOES, but how it FEELS. We teach it that even under pressure, it can achieve a sense of its own competence and internal satisfaction, making it a confident and cooperating partner.

From a training perspective, it is crucial in these situations to teach the dog that other options exist where it can redirect its stress, which it must get rid of, as nature says: “get rid of stress”. The principle of behavior redirection consists of equipping the dog with a functional alternative that brings it biological relief and social gain. Once the dog, through this experience, understands that this new strategy is more advantageous for it in a given context, it will begin to seek it out preferentially in stressful situations.

Conclusion 

Reactivity is not a diagnosis of the dog’s or the owner’s failure. It is an opportunity to build a relationship based on a deep understanding of the dog’s mind and instincts. In our training, we do not look for blind obedience based on repression, but confident partners who cooperate with us “with heart and soul”.

If you want to truly lead your dog, if you want to move from theory to practice and start building your dog’s real self-control, we have our new reactivity course for you: Reactivity in Context: The Path from Understanding Causes to Certainty on Both Ends of the Leash, which starts on March 7th.

Let’s create a relationship together where you no longer have to fight, but where you will be an understandable and trustworthy partner for each other. Our goal is to be your guides on the path to harmony that is built on science but experienced with the heart.

“In NePoPo®, dogs do not fight the system because they always find an advantage in it. They do it with heart and soul.” — Bart Bellon