The socialisation window in puppies - typically 3-14 weeks - is a critical welfare period that shapes lifelong behaviour, and inadequate socialisation is a leading cause of fear, aggression, and relinquishment.
Puppyhood socialisation welfare is one of the most impactful welfare interventions available because it shapes the entire lifetime experience of the dog. Puppies that miss appropriate exposure to people, environments, sounds, and other animals during the sensitive period become fearful adults who experience chronic stress in everyday situations. Fear is a significant ongoing welfare harm. Conversely, well-socialised puppies develop resilience, confidence, and the ability to cope with novel stimuli. Puppy farm conditions that restrict movement, social contact, and environmental exposure during the sensitive window create lifelong welfare deficits. Age of separation from mother also significantly affects adult behaviour.