The critical socialisation period in puppies determines adult behaviour, and failure to provide appropriate experiences during this window causes lifelong welfare problems.
The socialisation window is brief and cannot be reopened. Puppies that spend this period in kennels, isolated environments or with limited human exposure frequently develop adult anxiety and fear that significantly reduces quality of life for both dog and owner. Responsible breeding means puppies are raised in home environments with appropriate stimulation. Early puppy classes — even before full vaccination using appropriate health protocols — provide critical experiences. The welfare consequences of poor early socialisation — fearfulness, aggression and anxiety requiring lifelong management — are severe and largely preventable with appropriate preparation.