Fear of unfamiliar people is common in dogs and significantly impairs welfare and human-animal bonds. Early socialization and behavioral treatment improve outcomes dramatically.
Fear of strangers causes repeated acute stress during normal social situations that most dogs encounter regularly. Dogs that cannot comfortably greet visitors, strangers on walks, or veterinary staff experience significant chronic psychological distress. The social consequences also affect welfare - fearful dogs may be isolated from enriching environments, have reduced activity opportunities, and experience secondary stress from owner frustration or management failures. The risk of defensive aggression creates secondary welfare consequences including muzzle use and potential rehoming or euthanasia.