At what age is a dog “senior”?

There is no single birthday when a dog becomes “senior” — it depends mostly on size. Knowing the rough idea helps you start paying attention at the right time, without either worrying too early or missing the slow changes.

It is a proportion, not a birthday

Veterinary guidance defines “senior” as roughly the last quarter of a dog’s individually estimated lifespan, not a fixed age — and that estimate depends on the dog’s breed and size (AAHA, Canine Life Stage Definitions). Because larger and giant breeds tend to have shorter expected lifespans, they typically reach the senior stage earlier than smaller breeds do. There is no single number that fits every dog; your veterinarian can give the closest estimate for yours.

Source: AAHA, Canine Life Stage Definitions (2019)

Why the idea is only a prompt

The idea is a reminder to start noticing, not a diagnosis. What matters more than an exact age is the pattern of small changes — and, if anything looks sudden or painful, a veterinary check rather than a guess.

Adult and senior, together

BounceBack is made for adult and senior dogs — the whole span where a daily routine starts to make sense. It is a serving over food, weight-based, judged over time.