New Dog Owners
Puppy developmental stages: what to expect from birth to adulthood
11 min read
TL;DR
Puppies move through predictable stages. The socialisation period (about 3 to 12–14 weeks) is the most important: positive experiences with people, places, sounds, and other dogs during this window shape how confident your dog will be for life. Expect a fear period around 8–11 weeks, teething from about 3 to 6 months, and adolescence from about 6 to 18 months, when many dogs seem to forget their training. Large and giant breeds mature more slowly.
- Socialisation window: roughly 3 to 12–14 weeks. Make every new experience positive and gentle.
- First fear period: about 8–11 weeks — often just as puppies go home.
- Teething: about 3–6 months. Provide safe chews and expect mouthing.
- Adolescence: about 6–18 months (longer for big breeds). Training dips are normal.
| Stage | Approximate age | What is happening |
|---|---|---|
| Neonatal | 0–2 weeks | Eyes and ears closed; puppy relies entirely on mother |
| Transitional | 2–3 weeks | Eyes and ears open; first wobbly steps |
| Socialisation | 3–12/14 weeks | Learning what is safe and normal in the world |
| Juvenile | 3–6 months | Rapid growth, teething, testing boundaries |
| Adolescence | 6–18 months | Sexual maturity, independence, training dips |
| Social maturity | 1–3 years | Adult temperament settles |
Ages are approximate. Every puppy develops at its own pace, and small breeds generally mature faster than large and giant breeds.
Next in The First Year
Frequently asked questions
- When is the puppy socialisation period?
- The socialisation period runs from about 3 to 12–14 weeks of age. Positive experiences with people, places, sounds, and other dogs during this window have the biggest impact on adult confidence.
- When do puppies go through a fear period?
- Most puppies have a fear period at about 8–11 weeks, and many have a second one during adolescence, somewhere between 6 and 14 months. Keep experiences gentle and positive during these times.
- When does puppy adolescence start and end?
- Adolescence usually starts around 6 months and lasts until about 18 months, or up to 2–3 years for large and giant breeds. Training setbacks during this time are normal.
- When do puppies stop teething?
- Teething usually runs from about 3 to 6 months of age, with all adult teeth in by around 7 months. Some dogs keep chewing heavily for a while after.