Puppyweeks

Puppy guide

Puppy development, week by week

Every puppy moves through the same developmental stages — socialisation, fear periods, teething, adolescence — just on a timeline that shifts with their breed size. Here’s what’s happening, what’s normal, and what to watch for at each one.

• Training schedule by weekWhat to work on at each age, with links into the week-by-week guide.
• Guides comparedWeek-by-week vs AKC, blogs, and training apps — who each is for.

1. Weeks 1–2NeonatalIn their first two weeks, puppies are almost entirely dependent on their mother — eyes and ears closed, unable to regulate body temperature, movement limited to crawling toward warmth and milk.
2. Weeks 3–4TransitionalWeeks 3–4 are a sensory awakening.
3. Weeks 5–7Peak SocializationWeeks 5–7 are the peak of the socialisation window — puppies are learning, at a neurological level, what counts as normal and safe.
4. Weeks 8–10First Fear PeriodWeeks 8–10 are a puppy’s first fear period.
5. Weeks 11–12JuvenileBy weeks 11–12 the socialisation window is starting to close, so what a puppy has met by now largely sets their baseline for “normal.” Learning is fast but attention spans are short — keep training to 2–3 minutes.
6. Weeks 13–16Teething & Boundary TestingWeeks 13–16 bring adult teeth, relentless chewing, and boundary-testing as confidence grows.
7. Weeks 17–32Adolescence OnsetAdolescence is the canine teenage phase — hormones, selective hearing, distraction, and for many owners the hardest stretch.
8. Weeks 25–52Peak AdolescenceThis is the hardest stretch of adolescence, and it usually overlaps the second fear period — your confident dog may suddenly go wary of familiar things.
9. Weeks 37–78ConsolidationIn consolidation the frantic edge of early adolescence softens.
10. Weeks 53–104Young AdultThe first birthday is a handover, not a finish line — dogs are physically mature or close, but emotional maturity keeps developing, often into the second year.

Grounded in established canine behavioural science — see our sources.