Leash reactivity is when a dog exhibits fearful behaviors that may become aggressive when the dog is restrained by a leash, confined to a small space, or otherwise feels trapped. It is characterized by barking, lunging, growling, air snapping, or even biting. If left untreated, leash reactivity can develop into a long-term and chronic problem as fear develops into anxiety and stress. There is also a risk of redirection of the aggression, where the dog unpredictably turns their aggression on other animals or people, potentially causing harm. Causes of Leash Reactivity in Dogs Leash reactivity is caused by a variety of factors, including fear, anxiety, lack of socialization, and past negative experiences. Dogs that have not been properly socialized with other dogs and humans are more likely to develop confinement/leash reactivity, as they may feel threatened, nervous, or uncomfortable when they encounter people or other dogs. This feeling increases when the stimulus or trigger moves closer into your dog’s comfort zone. There are certain risk factors that can lead to this type of reactivity. These include being physically or mentally punished during training; having negative experiences while being on leash, such as being attacked by another dog; being shocked or choked during training; hearing loud noises; or exhibiting fearful behaviors while outside due to a lack of socialization. In some cases, leash reactivity may be due to an underlying medical condition such as pain, discomfort, or illness. It’s always important to chat with your veterinarian regarding anything related to your pet’s health and behavior.