The first 3 to 14 weeks of a puppy's life represent a critical socialisation period whose experiences shape behaviour and welfare for life. Understanding this window saves countless dogs from behavioural problems.
Puppy socialisation represents one of the highest-leverage welfare interventions in companion animal care, because experiences during this brief window determine lifetime behavioural outcomes for millions of dogs. Dogs with inadequate early socialisation face a lifetime of fear-based responses to normal everyday stimuli, requiring ongoing management and limiting their quality of life and the relationships they can form with humans. The welfare responsibility for socialisation lies primarily with breeders, who control the environment during the most critical early weeks, and with new owners who must continue the process through adolescence. Puppy farms and pet shops that separate puppies from mothers and littermates too early, fail to provide diverse experiences, and sell puppies without adequate socialisation create the behavioural welfare problems that present to rescue organisations and behaviourists for years afterward.