Leash reactivity in dogs is primarily a welfare problem caused by fear or frustration, not a training failure requiring punishment.
Leash reactivity welfare involves recognizing that the reactive dog is experiencing genuine emotional distress - fear, frustration, or overarousal - that is being expressed behaviorally. The welfare problem is the emotional state, not the behavioral expression. Punishment that suppresses barking and lunging while leaving the underlying emotional state unchanged, or worsening it through added aversive experience, reduces welfare while giving the appearance of improvement. Treatment that changes the emotional response to triggers genuinely improves the dog's subjective experience and welfare, not just the owner's experience of walking their dog.