Dog life stages by age
Senior status starts at age 6 for giant breeds and not until age 11 for small ones — the same birthday means very different things.
| Stage | Age / human equivalent |
|---|---|
| Puppy Growth, vaccinations and the socialisation window. | 0–6 months ≈ 0–10 human years |
| Adolescent Adult body, teenage brain. Most training setbacks happen here. | 7 months – 2 years ≈ 10–24 human years |
| Adult The long stable stretch. Length depends heavily on breed size. | 2 years – senior onset ≈ 24–50 human years |
| Senior Giant breeds hit this at 6, small breeds not until 11. | Senior onset – +3 years ≈ 50–70 human years |
| Geriatric Mobility, cognition and pain management take priority. | Beyond that ≈ 70+ human years |
When each size becomes a senior
| Small (under 20 lb / 9 kg) | 11 years |
|---|---|
| Medium (21–50 lb / 10–23 kg) | 10 years |
| Large (51–100 lb / 23–45 kg) | 8 years |
| Giant (100 lb+ / 45 kg+) | 6 years |