What Is Reactivity in Dogs? Understanding the Causes and What It Really Means

Learn what reactivity in dogs really means, why it happens, and how understanding emotional drivers is key to supporting dogs ethically.

Reactivity in dogs is a term used to describe a heightened emotional response to specific triggers or situations. These responses may include behaviours such as barking, lunging, growling, freezing, or attempts to escape, and can feel sudden or intense for both dogs and their owners.

Reactivity is not a training failure, a lack of control, or a dog being “naughty”. Instead, it is a sign that a dog is struggling to cope emotionally in that moment. Understanding what drives reactive behaviour is an essential step in supporting dogs in a way that prioritises welfare, safety, and long-term emotional wellbeing.

What Does Reactive Behaviour Look Like?

Reactive behaviour can vary widely between individual dogs and contexts. Some common signs include:

Barking or vocalising at particular triggers
Lunging or pulling strongly on the lead
Stiffening, freezing, or intense staring
Growling or snapping when feeling overwhelmed
Attempts to increase distance or avoid a situation

These behaviours are forms of communication. They tell us that the dog is experiencing stress, fear, frustration, or uncertainty, and does not yet have the skills or emotional capacity to cope comfortably with the situation.

Common Underlying Causes of Reactivity

Reactivity does not have a single cause. It usually develops through a combination of emotional, environmental, and sometimes biological factors. Understanding these influences helps us respond with empathy rather than judgement.

Fear and Anxiety

Fear-based reactivity is one of the most common presentations. A dog may react because they perceive a situation, person, or other dog as threatening. The behaviour is often an attempt to create distance and feel safe, rather than an intention to cause harm.

Frustration and Over-Arousal

Some dogs experience reactivity when they are unable to access something they want, such as greeting another dog or moving freely. When arousal levels rise and the dog lacks coping strategies, this frustration can spill over into reactive behaviour.

Defensive or Protective Responses

Dogs may react defensively when they feel their personal space, resources, or sense of safety is at risk. These responses are rooted in self-preservation, not dominance or a desire to control.

Limited or Inappropriate Early Experiences

Dogs who did not have positive, carefully managed exposure to a variety of environments, people, or dogs during early development may find unfamiliar situations overwhelming later in life. This does not mean they were “poorly socialised”, but that their experiences may not have supported emotional resilience.

Pain, Discomfort, or Health Factors

Physical discomfort can significantly affect behaviour. Pain, illness, or sensory changes may reduce a dog’s ability to tolerate stress, making reactive responses more likely. Veterinary input is always an important part of assessing behaviour change.

Reactivity and Aggression: Understanding the Difference

Reactivity and aggression are not the same, although they can appear similar from the outside.

Reactive dogs are typically overwhelmed or unsure, responding to emotional pressure rather than acting with intent to harm. However, if a dog is repeatedly exposed to situations they cannot cope with, and their signals are not recognised or respected, reactivity can escalate over time.

This is why early, welfare-centred intervention is so important. Approaches that rely on punishment or suppression may stop visible behaviour temporarily, but they do not address the underlying emotional state and can increase fear, stress, and risk.

Why a Force-Free Approach Matters

From a force-free and behaviourally ethical perspective, the goal is not to “stop” behaviour, but to change how the dog feels about the situations they find difficult. This involves:

Reducing exposure to overwhelming triggers
Supporting emotional regulation
Teaching alternative coping skills
Using desensitisation and counter-conditioning appropriately
Respecting the dog’s thresholds and individual needs

When dogs feel safer, behaviour changes naturally follow.

A Supportive Next Step

If you’re living with a reactive dog and want a clear, compassionate understanding of reactivity, alongside practical, welfare-focused guidance, my online course From Reactive to Relaxed was created to support you.

The course explores:

What reactivity really is and why it develops
How stress and emotional overload affect behaviour
Creating calmer foundations in daily life
Ethical equipment and motivators
Foundation and lead skills that prioritise safety and choice
Desensitisation and counter-conditioning explained clearly
Bringing everything together in real-world situations

The course is self-paced, designed to fit around your life, and includes lifetime access, so you can return to any section whenever you need to.

You can learn more about From Reactive to Relaxed here: https://www.victoria-cooper.co.uk/courses/from-reactive-to-relaxed

Categories: : Reactivity