Training methods have profound impacts on dog welfare, with evidence strongly favouring reward-based over punishment-based approaches.
Training methods affect dog welfare beyond the training session. Aversive methods including shock collars, choke chains, and physical punishment cause acute pain and fear, suppress normal behaviours, damage the human-dog relationship, and increase risk of fear-based aggression. This is not a matter of debate in animal behaviour science — the evidence for harm from aversive methods is robust. Reward-based training achieves equivalent or better results without these welfare costs.