When is a dog "senior"?
There is no single age — it depends on breed and size:
| Size | Approximate weight | Senior threshold |
|---|---|---|
| Small | < 10 kg | 10-11 years |
| Medium | 10-25 kg | 8-9 years |
| Large | 25-45 kg | 7-8 years |
| Giant | > 45 kg | 5-6 years |
Giant breeds age fastest — a Great Dane is "old" at 6, while a Yorkshire Terrier can be in full swing at 12.
Typical physical changes
- Joints and mobility: arthritis is very common. Signs include stiffness on rising, morning lameness that eases with warmth, reluctance on stairs.
- Sight and hearing: a cloudy lens (cataract or harmless nuclear sclerosis) is normal with age, as is partial deafness.
- Cognition: canine cognitive dysfunction (the dog equivalent of Alzheimer’s) affects many older dogs. Signs: disorientation, disrupted sleep-wake cycle, night-time vocalisation.
- Weight: tendency to gain or lose weight. Both warrant a vet visit.
- Teeth: tartar build-up and dental infections that can affect kidneys and heart.
Senior vet checks
From 7-8 (sooner in large breeds), step up from yearly to six-monthly health checks. Each check should include:
- Full physical examination
- Blood and urine tests (early detection of kidney, liver and thyroid disease)
- Blood pressure
- Dental assessment
- Joint mobility check
Senior nutrition
Nutritional needs shift with age. Good senior diets are formulated with:
- Fewer calories: metabolism slows and activity drops.
- More high-quality protein: contrary to the old myth, older dogs need more protein to maintain muscle mass, not less.
- Omega-3 and antioxidants: for joints and cognition.
- Glucosamine and chondroitin: joint support.
- Lower sodium: for dogs with cardiac issues.
Talk to your vet about whether a senior food is right for your specific dog, or whether a prescription diet is needed.
Adapting the home
- Orthopaedic bed: memory-foam beds ease arthritic joints.
- Ramps instead of jumps: for the sofa or the boot of the car.
- Non-slip flooring: smooth wood and tile floors are hazardous for arthritic dogs — runners and rugs help.
- Raised feeder: easier to eat and drink for dogs with neck pain.
- Temperature: older dogs tolerate cold less well. Coats and warm bedding in winter.
Exercise in the senior years
Exercise should not stop — it should adapt. Several short walks beat one long one. Swimming and canine hydrotherapy are excellent for joints. Mental exercise (snuffle mats, Kong toys, scent games) keeps the brain active without joint strain.
Supplements that help
- Glucosamine + chondroitin + MSM: joint support.
- Omega-3 (EPA+DHA): krill or salmon oil. A natural anti-inflammatory.
- Antioxidants (vitamin E, selenium): cognition and immune function.
Always check with your vet before adding supplements — some interact with medication.
How CanAI helps
The CanAI senior section tracks mobility, weight, medication and check-up cadence so nothing slips through. Ask the AI chat for breed-specific senior care plans.