Quick answer: when an older dog's back legs tremble while they stand, the most common reasons are weakness and discomfort: back leg muscles that have lost bulk tire quickly holding the dog up, and sore hips, knees or a sore back can make the legs quiver. Trembling is one of the signs vets ask about when screening for chronic pain. But tremors in the back legs can also point to a spinal cord problem, and less often to illness such as kidney disease, an underactive thyroid or low blood sugar, so it deserves a vet check rather than being put down to age. If the shaking came on suddenly, affects the whole body, or comes with collapse, pain or wobbling, call your vet the same day.
Transparency note: this page is written by MedPaw, which makes a joint supplement. It is general information, not a diagnosis. Checked 9 October 2026.
This page is about trembling in the back legs of older dogs. For shaking all over (excitement, cold, fear, nausea), see our guide to why dogs shake and tremble.
Likely causes
Why an older dog's back legs might shake when standing
| Cause | What you might notice | What to do |
|---|---|---|
| Muscle weakness or loss | Thin thighs, bony hips, shaking worse after walks or when standing still for a while | Vet check, then gentle strength work |
| Arthritis or joint pain | Stiff after rest, slower on walks, reluctant to jump, shaking when getting up | Vet check; pain relief if needed |
| Back or spinal problems (including a slipped disc) | Hunched back, yelping when lifted, wobbly legs, scuffing feet | Call your vet promptly; same day if sudden or painful |
| Nerve disease such as degenerative myelopathy | Gradually weaker, wobbly back legs, scuffing or crossing feet, usually not painful | Vet check, including a neurological examination |
| Illness: kidney disease, underactive thyroid, low blood sugar | Drinking more, weight change, low energy, feeling the cold, weakness | Vet check and blood tests |
| Cold | Shaking eases once warm; thin-coated or lean dogs | Warm bed, coat on cold walks; check if it persists |
| Poisoning | Sudden tremors, often whole-body, twitching, vomiting, agitation | Emergency: call your vet straight away |
For guidance only, not a diagnosis.
Weakness and pain
Standing still is hard work for weak muscles. In many older dogs, the back legs lose muscle first, often because sore joints mean they've quietly been taking weight on their front legs. PDSA lists "narrowing of the hips and back end" among the signs of arthritis in dogs, along with stiffness after rest and slowing down on walks. If the trembling is worse after exercise, or eases once your dog lies down, weakness or pain is a likely part of the picture. Our guides to muscle wasting and back legs giving way go into more detail.
Spine and nerves
The Canadian Veterinary Medical Association notes that when tremors affect the hind legs, "there may be problems with the spinal cord", and lists kidney failure, hypothyroidism and low blood sugar among other possible causes. PDSA's guide to IVDD (slipped disc) lists back pain, wobbliness, weak legs and scuffing feet, and degenerative myelopathy causes weak, wobbly back legs that gradually get worse, usually from around nine years old. These need a vet's diagnosis, not home treatment.
Red flags: when to see a vet
Book an appointment for any new trembling that keeps happening. Call your vet the same day, or your emergency vet out of hours, if your dog:
- started shaking suddenly, or the tremor involves the whole body or head
- might have eaten something toxic, such as medication, chocolate or slug pellets
- collapses, can't stand, or can't use their back legs
- yelps, has a hunched back, or seems in pain
- is wobbly, knuckles over, crosses their back legs or scuffs their back paws
- is also vomiting, off food, drinking much more than usual or very lethargic
- seems confused or unresponsive while shaking, which could be a seizure
What you can do at home
- Film it. Tremors often stop in the consulting room. A short video, plus a note of when it happens (after walks, standing to eat, first thing in the morning, when cold), helps your vet a lot.
- Make floors grippy. Weak legs shake more on slippery floors. Put rugs or runners on laminate and tiles; see our guide to non-slip flooring.
- Keep them warm. A thick, supportive bed away from draughts (see beds for senior dogs) and a coat for cold walks.
- Short, frequent walks rather than one long one, on flat ground. Let them rest when they want to.
- Support them if needed. A rear support harness or sling can help with steps and getting up; see our harness and sling guide.
- Keep them slim. Less weight means less work for weak back legs.
Once your vet has ruled out spinal and medical causes, gentle exercises to strengthen the back legs can help build back some of the muscle that keeps them steady.
Can a supplement help?
Be clear about what a supplement can and can't do. It won't stop a tremor caused by a spinal, nerve or hormonal problem, and it isn't a painkiller. If your vet finds that stiff, sore joints and muscle loss are behind the shaking, a joint supplement can support joint health alongside their plan, helping your dog stay comfortable enough to keep moving, which is what protects muscle. 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, and you should check with your vet first if your dog has a condition such as kidney disease or takes medication. See the best supplement for a dog losing muscle and the best joint supplements for senior dogs.
Frequently asked questions
Is it normal for an old dog's back legs to shake?
It's common, but that doesn't mean it should be ignored. Weakness and joint pain are frequent causes and can often be helped. Spinal, nerve and medical causes need ruling out, so book a vet check.
Why do my dog's back legs shake after a walk?
Tired, weak muscles often tremble after exercise, and sore joints can add to it. It may mean the walk was too long for your dog now. Try shorter walks and mention it to your vet, especially if the shaking is new or getting worse.
Can arthritis make a dog's legs shake?
Yes, it can. Pain and the muscle loss that often comes with arthritis can both cause trembling, particularly when standing still or getting up. Trembling is one of the signs vets ask about when screening for chronic pain.
Do shaking back legs mean my dog is dying?
Not on its own. Many causes, such as arthritis, muscle loss or an underactive thyroid, can be managed. A vet check is the best way to find out what's behind it and what can be done.
Should I keep walking my dog if their back legs shake?
Usually yes, but shorter and gentler, on flat ground, until your vet has seen them. Stop if the shaking gets worse, your dog wobbles, or they want to lie down. Gentle, regular movement helps protect muscle.
Could it be degenerative myelopathy?
It's possible, especially in older German Shepherds, Boxers, Corgis and Bernese Mountain Dogs, but many other conditions look similar. Degenerative myelopathy usually causes gradually worsening wobbliness and scuffing of the back feet. Only a vet can diagnose it.
