Aggression assessment in dogs affects welfare through both the evaluation process itself and the life-altering decisions about euthanasia, management, or rehabilitation that follow from assessments.
Aggression assessment has profound welfare implications for individual dogs whose life or death depends on behavioral evaluation. The limitations of behavioral assessment tools — particularly their poor predictive validity when applied in artificial shelter environments to stressed dogs — means that assessment errors in either direction cause welfare harm. False positives — identifying dogs as dangerous that are not — leads to unnecessary euthanasia of treatable animals. False negatives — missing genuinely dangerous behavior — risks human injury and subsequent dog euthanasia. The welfare-appropriate approach to aggression assessment prioritizes medical investigation to exclude pain as a cause, careful behavioral observation in naturalistic rather than artificial testing conditions, and access to treatment resources including behavioral modification and medication before euthanasia decisions are made for dogs with treatable behavior.