Quick answer: when an older dog starts lagging behind on walks, the most common reason is discomfort, usually arthritis in the hips, knees, elbows or back. "Lags behind on walks" is one of the questions vets use to screen for chronic pain in dogs. But it can also be a sign of a heart or breathing problem, an underactive thyroid, extra weight, sore feet or simply that the walk is now too long. Rather than putting it down to age, book a vet check, and shorten walks in the meantime.
Transparency note: this page is written by MedPaw, which makes a joint supplement. It is general information, not a diagnosis. Checked 9 October 2026.
Likely causes
Why an older dog might lag behind on walks
| Cause | What you might notice | What to do |
|---|---|---|
| Arthritis or joint pain | Stiff after rest, slower on hills, sits down mid-walk, sleeps more, reluctant to jump | Vet check; pain relief if needed; shorter, more frequent walks |
| Muscle loss in the back legs | Thinner thighs, bony hips, struggles to get up | Vet check, then gentle strength work |
| Heart disease | Stops for rests and won't go on, worse in warm weather, coughing, faster breathing at rest | Vet appointment soon; urgently if they faint or struggle to breathe |
| Breathing or airway problems | Noisy breathing, a changed bark, tiring very quickly, heavy panting | Vet appointment; urgently if breathing is laboured |
| Underactive thyroid | Weight gain, low energy, feeling the cold, fur loss | Vet check and blood test |
| Extra weight | Puffing, wanting to stop, harder to feel ribs | Weigh your dog and agree a target with your vet |
| Sore feet or nails | Licking paws, limping on hard ground, long nails | Check pads, between toes and nails |
| Eyesight, hearing or confusion | Hesitant in dim light, unsure in new places, stops and stares | Vet check; keep to familiar, well-lit routes |
For guidance only, not a diagnosis.
Arthritis is the most common culprit
PDSA lists "slowing down on walks" alongside stiffness, limping, sleeping more and reluctance to jump as signs of arthritis in dogs. Dogs rarely cry out with long-term joint pain. They just do less: they walk more slowly, stop more often, or turn for home early. Our guide to spotting arthritis in older dogs covers the early signs in more detail.
Heart and breathing problems
Agria's senior veterinary adviser describes reduced exercise tolerance as a sign of heart disease: "dogs with heart disease will stop unexpectedly for rests on walks and refuse to go on as they usually would", often more noticeably in warm weather. Other clues are a soft cough that is worse in the evenings and a resting breathing rate that creeps up over time. Older dogs can also develop airway problems such as laryngeal paralysis, which makes them tire and pant heavily.
Thyroid and other illness
PDSA lists "struggling to keep up on walks" among the signs of an underactive thyroid, along with weight gain and low energy. Its guide to low energy in dogs also includes anaemia, kidney and liver disease, diabetes, pain and obesity. A blood test is often part of the check-up for this reason.
Red flags: when to see a vet
Book a routine appointment for any new, lasting change in how your dog walks. Contact your vet the same day if your dog:
- collapses, faints or seems wobbly or disorientated
- is breathing hard, noisily or fast after only a short distance, or at rest
- has pale, grey or blue-tinged gums
- has a cough, a swollen belly, or has stopped eating
- is limping badly, won't put a leg down, or cries out
- drags or scuffs their back paws or their back legs shake
- slows down suddenly on a hot day: stop, get them into shade and cool them, and call your vet
What you can do at home
- Shorter, more frequent walks. Two or three short walks are usually kinder than one long one. Let your dog set the pace and turn back before they flag, not after.
- Let them sniff. A slow, sniffy walk is still good exercise and mental stimulation. A dog who has stopped sniffing and just pants may be uncomfortable.
- Choose easier routes. Flat, soft ground and fewer hills. Walk in the cooler parts of the day in summer.
- Don't drag them on. Pulling a reluctant dog forward on a collar can hide a problem and makes walks unpleasant. A comfortable harness helps.
- Check their feet. Look at pads, between toes and nail length after walks.
- Keep a note or video. Note when they lag (start, middle, end of walk, hot days, hills) and film it for your vet.
- Watch their weight. See our guide to weight and joint health.
Once your vet has ruled out heart and other medical causes, gentle exercises to strengthen the back legs and our guide to exercising older dogs safely can help keep them moving.
Can a supplement help?
If your vet finds your dog is lagging because of stiff, sore joints, a joint supplement can support joint health alongside their plan, which may include pain relief, weight loss and adjusted exercise. It won't help a heart, breathing or thyroid problem, and it isn't a painkiller. The strongest evidence among joint supplements is for omega-3s, according to a 2022 review of 72 trials; glucosamine and chondroitin did not relieve pain in that review.
For an older dog with stiff joints, we'd suggest MedPaw Hip & Joint Chews: a soft chew given like a treat, with all six key joint actives including green-lipped mussel, a source of omega-3s, and a 60-day money-back guarantee. It contains mollusc and gluten, so it isn't suitable for dogs with a shellfish allergy, and you should check with your vet if your dog has a condition or takes medication. See the best joint supplements for senior dogs for how to choose, or the best supplement for a dog losing muscle if their back legs look thinner.
Frequently asked questions
Is it normal for an old dog to slow down on walks?
Older dogs often want shorter, slower walks, but a clear change, such as lagging behind, stopping or refusing to go on, is worth a vet check. Arthritis, heart disease and thyroid problems can all look like "just getting old", and most are treatable or manageable.
How far should I walk my old dog?
There's no set distance. Go by your dog: aim to finish while they are still keen, and check they are no stiffer the next day. Several short walks are usually better than one long one. Your vet can advise if your dog has a condition.
Should I make my dog keep walking when they lag behind?
No. Encourage gently, but if they keep stopping, head home and make a note of when it happened. Pushing a dog who is sore or breathless can make things worse and can hide signs your vet needs to know about.
Why does my dog lag on the way out but walk fine on the way home?
That pattern is common and can simply be about motivation. But if it's new, or your dog is also stiff, sleeping more or reluctant to jump, mention it to your vet, as dogs with joint pain often show it in small ways first.
Could my dog's heart be the reason they lag behind?
It can be. Stopping for rests and refusing to go on, especially in warm weather, along with coughing or faster breathing at rest, can be signs of heart disease. Your vet can listen to your dog's heart and arrange tests if needed.
Will a joint supplement help my dog keep up?
Only if stiff joints are part of the problem, and only alongside your vet's plan. MedPaw supports joint health; it isn't a painkiller and won't help heart, breathing or thyroid problems.
