Why is my dog aggressive to strangers and other dogs? Barking or growling at other dogs or people, lunging on the lead with a full threatening display, this usually comes down to fear. A dog that feels unsafe is reacting with a survival response, the same fight, flight or freeze reflex that shows up in any animal facing a threat. Some dogs default to confronting the trigger (fight), others would rather move away (flight), but a dog trapped on a lead or in a confined space doesn't have that option, leaving a threatening display as the next best thing. What this looks like: Posturing tall, tensing up, raised hackles, a hard stare, snarling, lip-curling, growling, barking, lunging, air-snapping and, in the worst case, biting are all part of the same threat display. If it works, the scary thing backs off, or an owner drags the dog away, the dog feels relief, and that relief reinforces the behaviour. How we approach a reactive dog: The first step is understanding your dog's baseline arousal and anxiety level. A generally easy-going dog who only reacts to specific triggers is a different starting point to a dog who's restless and hyper-alert most of the time. Identifying and working with triggers: Triggers are identified one at a time, and effective approaches include classical and operant counter-conditioning combined with desensitisation, Behaviour Adjustment Training (BAT), and matwork. Practical steps that help: Muzzle training and understanding your own reactions are key to managing reactive dogs. Getting the right support: A skilled, experienced behaviourist can make the difference between ongoing frustration and a clear, workable plan.