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  • Writer's picturePuppy Talk

Critical periods in puppy development: 21-49 days

Updated: Feb 1, 2020

Puppy playtime is more than just puppy fun time. Between four and sixteen weeks of age, play is mayhem, fun and adorableness but also a critical period of learning. During this time, the pups must learn how to be loving, enjoyable, confident members of a human pack - to become well-prepared for their forever homes.

"At the 28th day the learning stage has just become established, and the puppy is emotionally stabilized to where he can be taught simple things. What he learns during the next few weeks he will not forget. Like a child, he will learn things on his own if not taught, and what he learns may be things that he should not have learned; having been learned at a this age, they will be very hard indeed to correct later." - Pfaffenberger, The New Knowledge of Dog Behavior 1963

Critical Periods in the Development of Social Behavior in Puppies Adapted from J.P. Scott, PhD

  • Canine Socialization Period - 21 to 49 Days Awareness Period - 21 to 28 Days

  • Human Socialization Period - 50 to 84 Days (7 to 12 weeks) Fear Impact Subperiod 8 to 11 Weeks

  • Seniority Classification Period - 12 to 16 Weeks

  • Second Fear Impact Period - 6 to 14 Months

  • Young Adulthood - 18 to 24 months

  • Maturity 2-4 years

To ensure the best possible start in life, provide young puppies a variety of physical, mental and social experiences. Learn more about puppy training and dog behavior.

Pics of puppy "playtime" at 32 days old below.

© Lori Rodriguez and www.ctgermanshepherddogs, 2020. Unauthorized use and/or duplication of this material without express and written permission from this site’s author and/or owner is strictly prohibited. Excerpts and links may be used, provided that full and clear credit is given to Lori Rodriguez and www.ctgermanshepherddogs with appropriate and specific direction to the original content.

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