Dog training glossary
Leash Reactivity
Quick answer
A dog that barks, lunges, or growls at triggers specifically while on leash, despite behaving differently off leash.
Written by the TailorPup team, updated September 2026. See our editorial approach.
What it means
Leash reactivity is distinct from general reactivity because the leash itself is often part of the cause, it removes a dog's ability to create distance or flee, which can push a dog toward an exaggerated "fight" response instead. Many leash-reactive dogs are perfectly comfortable with the same trigger off leash in a controlled setting, which is a useful diagnostic clue rather than a contradiction.
A real example
A dog that plays calmly with other dogs at daycare, off leash, lunges and barks at those same dogs when passing them on a leashed sidewalk walk.
Common mistake
Assuming a leash-reactive dog is simply "aggressive" based on leashed behavior alone, without considering how much the leash itself, and the restricted ability to move away, is contributing to the reaction.
Related terms
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