When Is a Dog Considered a Senior?

How veterinarians define senior

The canine life stage guidelines from the American Animal Hospital Association (AAHA, 2019) don't tie the senior stage to a specific number of years. Instead, senior is described as the last quarter of a dog's expected lifespan. A dog expected to live to 12 would, by this definition, be a senior from around nine.

That makes the definition fairer across breeds: a small dog with a long life expectancy becomes a senior later than a giant dog with a shorter one.

Typical senior age by size

The table shows roughly when dogs in each size class are considered seniors on this site, and what that equals in human years with our model. Notice that all sizes land close to the same human age, even though the dog's age differs. Our breed pages use the breed's own senior age where it differs from this.

Signs your dog is getting older

• Less stamina on walks and a need for longer rests.
• Stiffness when getting up, especially after resting.
• Grey hair around the muzzle and eyes.
• Changed sleep patterns, reduced hearing or eyesight.
• Changes in appetite, weight or how much your dog drinks – these should always be checked by a veterinarian.

What changes when your dog becomes a senior?

AAHA recommends that healthy adult dogs see a veterinarian at least once a year, and many veterinarians recommend closer follow-up as dogs age. That makes it easier to catch dental problems, joint issues or changes in blood work early.

Many senior dogs also benefit from an adjusted diet, shorter but more frequent walks and non-slip surfaces at home. Ask your veterinarian what suits your dog.