Leash reactivity — aggressive or fearful behavior toward other dogs or people on leash — is one of the most common behavioral welfare problems in pet dogs, requiring systematic behavior modification for improvement.
Leash-reactive dogs often have severely restricted lives — unable to enjoy normal walks, avoiding other dogs, and causing stress for owners who struggle to manage them. This restriction affects both the dog welfare through reduced exercise and social opportunity and the owner-dog relationship. The fear or frustration underlying reactivity represents genuine emotional distress that is inadequately addressed by management alone. Professional behavior modification using counterconditioning to change the emotional response to triggers produces lasting welfare improvement. Owners who attribute reactivity to dominance or spite and use punishment-based responses typically worsen both the behavior and the welfare problem.