Dog aggression towards humans is frequently rooted in fear, pain, or inadequate socialisation, and welfare-centred assessment examines the dog's motivations rather than simply the behaviour.
Aggressive dogs are frequently welfare-compromised animals living in chronic fear or pain, for whom biting is the only effective communication of distress available after other signals have been ignored. Welfare-centred assessment investigates underlying pain, fearfulness, and socialisation history before recommending behaviour modification. Punitive approaches that suppress warning signals without addressing underlying fear can produce dogs that bite without warning — a welfare harm to both dog and humans. Successful treatment reduces the dog's need to express aggression by addressing the fear or pain driving it. Euthanasia for aggression, while sometimes necessary, is most ethically defensible when all welfare-centred approaches have been exhausted.