What makes a dog reactive?
Reactivity is a big reaction to something your dog sees, hears or smells: barking, lunging, growling or whining that’s hard to call off once it starts. From the outside it often looks the same. What differs is what your dog wants in that moment, and that changes what helps. In our consultations, we see four common patterns.
Fear: wanting distance
A worried dog wants more space. It may back away, freeze or hide, or bark to make space when it can’t leave, such as on a lead or in a lift lobby. Help starts with keeping it far enough away to feel safe, and pairing what it fears with something good.
Frustration: wanting to get there
Some dogs want to reach the other dog or person to sniff, greet or play, and the lead or a gate stops them. They whine, strain and pull, and are often calmer off the lead. Teaching your dog to turn back to you, and making it clear when it can say hello, helps.
Wanting it gone
Some dogs run up or hold their ground and bark until whatever set them off leaves, then settle. In our experience, some of these dogs aren’t scared in the moment. They’ve learnt that barking makes things go away, and each time it works, the habit grows. Stopping your dog from practising the reaction and teaching it something else to do carry the work.
Wanting to take it on
A few dogs go quiet, stare and close the distance, or go after the other dog or animal to chase or fight. This can come from prey drive, or in some dogs from competing with dogs of the same sex. Careful management, planned introductions and an alternative behaviour matter most here.
Most dogs show a mix, and the mix can change as training goes on. If your dog has bitten, or the change came on suddenly, start with your vet and a behaviour professional. For the training itself, read our guide to reactive dog training.
Common questions
Is my dog reactive or aggressive?
Reactivity is a big reaction your dog struggles to call off once it starts: barking, lunging or growling at whatever sets it off. Aggression covers anything from a warning growl to a bite. The two overlap, and reactivity left alone can grow into aggression over time, so it’s worth taking seriously whichever word fits best right now.
Why is my dog fine off lead but not on lead?
Being held back adds frustration, and that extra arousal can be what tips a dog over the edge. A worried dog on a lead also can’t get away from what worries it. Off lead, a dog that wanted to greet can go and greet, and a worried dog can move away.
Can a fearful dog become aggressive?
It can. A dog that barks and then sees the scary thing leave learns that barking works. Over time some dogs grow more confident and start running at things to drive them off, and a few go further and start going after them. That’s why stopping your dog from practising the reaction matters, whatever is driving it.