Quick Answer

Reactivity describes an intense or disproportionate response to a trigger — often involving barking, lunging, freezing, pulling, or escape. It is not a complete diagnosis or identity. Reactivity can be influenced by frustration, fear, overarousal, pain, learning history, and genetics. Effective support starts with understanding the individual dog's triggers and context.

What This Term Means

Reactivity is a behavioural description, not a diagnosis. It describes an intense response to a trigger. Common triggers include other dogs, people, vehicles, movement, sounds, barriers, and leashes. The function of the response varies — it may be fear-based, frustration-based, overarousal-based, or related to pain or health. Understanding the function is essential for effective support.

What It May Look Like

Reactivity may appear as barking, lunging, pulling, freezing, staring, spinning, redirected behaviour, or escape. The specific presentation varies by dog and trigger. Some dogs are reactive only to specific triggers; others are reactive in multiple contexts. The intensity can range from mild alertness to severe, difficult-to-redirect responses.

Why It May Happen

Reactivity can be influenced by frustration, fear, overarousal, pain or health, learning history, genetics, and breed tendencies. A dog who is frustrated by barriers may become reactive at fences. A dog who is fearful of strangers may become reactive when approached. A dog in pain may have a lower threshold. The cause is often multifactorial.

Why Context Matters

Reactivity is contextual. A dog may be reactive on leash but comfortable off leash. A dog may be reactive to large dogs but not small dogs. A dog may be reactive in the evening but not in the morning. Understanding the specific contexts where reactivity occurs helps identify triggers and build an effective plan. Reactivity is not a fixed trait — it can change with training, management, and experience.

What to Observe

• What triggers the response — specific dogs, people, vehicles, sounds, or movement
• Distance — how far away the trigger is when the response begins
• Body language — stiffness, fixation, vocalization, or escape
• Recovery — how long it takes to return to regulation after the trigger passes
• Whether the response is the same in different contexts
• Whether the response has changed recently or suddenly

Management

Management includes distance, visual barriers, route planning, equipment, avoiding rehearsal, supporting recovery, muzzle conditioning where appropriate, and predictable exits. The goal is to prevent the dog from rehearsing the reactive response while building alternative skills. Management is not failure — it is an essential tool that keeps the dog below threshold.

Training Principles

• Work below threshold — if the dog cannot take food or respond, increase distance
• Change emotional associations through positive pairing with triggers
• Reinforce functional behaviour — looking at the handler, disengaging, choosing calm
• Build disengagement — teach the dog they can look away from the trigger
• Support recovery — allow time to return to regulation after each exposure
• Generalize gradually — practise in different contexts only when the dog is ready

Common Mistakes

• Getting too close to triggers too quickly
• Repeating cues the dog cannot respond to when over threshold
• Punishing the reactive response, which may suppress communication without changing the emotion
• Not accounting for trigger stacking from earlier in the day
• Expecting quick results from a complex behaviour pattern
• Treating all reactivity as the same regardless of function

What Not to Assume

• Do not assume reactivity means aggression — they are related but distinct
• Do not assume the dog is being dominant or stubborn
• Do not assume one technique works for every reactive dog
• Do not assume reactivity is permanent — it can change with training
• Do not assume management is failure — it is an essential tool

When to Seek Professional Help

Seek professional help if there is a bite history, redirected aggression, severe distress, sudden change, inability to function, or safety concerns. A qualified trainer or behaviour professional can help assess the function of the reactivity, build a structured plan, and ensure safety. Do not attempt to address severe reactivity without professional guidance.

When to Speak to a Veterinarian

Put It Into Practice

For members: Explore pattern games, orientation, distance work, recovery, U-turns, and handler check-in exercises in the training app. Use Build My Session to create sessions that work below threshold. For visitors: Understanding reactivity is the first step. Explore the Academy training app for structured exercises that support reactive dogs.

Related Definitions

Frequently Asked Questions

Sources and Further Reading