Glossary

Leash reactivity

Barking, lunging or growling at other dogs or people when on a leash, often from fear or frustration at being unable to move freely.

Also called: leash aggression, leash frustration, barking and lunging on leash, reactive on leash

Leash reactivity is a pattern in which a dog that is calm or friendly off leash barks, lunges or growls on leash. The leash removes the option to move away, so a nervous dog may feel it has to fight off a threat, and an eager dog may become frustrated when held back from a greeting.

It is often called leash aggression, but many dogs are scared or frustrated and not intending to harm. Tight leashes and nervous handlers can make it worse, as the dog feels the tension and links dogs with it.

Trainers work by finding the dog's threshold distance, rewarding calm behavior at that distance and shrinking the gap slowly. Avoiding the trigger in the meantime helps. Seek professional help if the dog has bitten or the owner feels unsafe.

Last reviewed November 8, 2026

In the index now

Related terms

Reactivity A dog's exaggerated reaction, such as barking, lunging or freezing, to a trigger like other dogs, people or noises. Threshold The point at which a dog goes from noticing something to reacting to it, often described as a distance or an intensity. Desensitization and counter-conditioning A training plan that exposes a dog to a fear trigger at a level it can handle while pairing it with something good, to change how the dog feels. Loose-leash walking Walking with a dog beside or near the handler on a slack leash, without the dog pulling.