Large and giant breeds are often considered senior from as young as five or six, while small breeds may not reach that stage until nine or ten. Ask your vet where your own dog's breed and size actually falls, rather than assuming. What follows applies once a dog reaches that stage, whenever it arrives for them.
Weight, in both directions
Slow weight gain is common as activity naturally drops, and it puts real extra strain on ageing joints. Slow weight loss can be just as easy to miss and is often the first sign of dental pain, organ changes, or reduced appetite. Either direction is worth tracking properly rather than trusting the eye, since gradual change over months is exactly what's hardest to notice day to day.
Mobility and stiffness
Slower to get up, more hesitant on stairs, reluctant to jump into the car. It's easy to write all of this off as "just getting old," but arthritis is genuinely manageable with the right support, and catching it earlier means more comfortable years, not just longer ones.
Cognitive changes
Canine cognitive dysfunction, the dog equivalent of dementia, is more common than most owners realise. Watch for disorientation in familiar spaces, changed sleep patterns, increased confusion or anxiety, and house-trained dogs having accidents indoors. These are medical signs, not behavioural ones.
Dental health
Dental disease is one of the most common, and most under-treated, conditions in older dogs. Bad breath isn't just unpleasant, it's usually a sign of real disease underneath, and untreated dental pain can quietly suppress appetite and energy for a long time before anyone connects the dots.
What to actually track
- Weight, checked and logged monthly rather than estimated by eye
- Mobility, noting new stiffness, hesitance on stairs, or reluctance to jump
- Appetite and water intake, since both often shift before anything else does
- Sleep and confusion, especially any new disorientation in familiar places
- Lumps and bumps, checked regularly since new growths become more common with age
Why a written record matters more now
The whole point of senior-year monitoring is catching slow trends, and slow trends are exactly what memory is worst at holding onto. Halo logs weight and daily notes automatically over time, so a genuine change stands out clearly instead of getting lost between one vague impression and the next.