Dog Back Legs Shaking: Causes and When to Worry

Many owners notice the quivering when their dog is standing still, waiting for food, or getting up after a nap, and it often settles once the dog lies down.

That said, shaking in a dog's back legs can also be the first visible sign of a joint or spine problem that is worth catching early, and a small number of causes need same day care. This guide walks through the everyday explanations first, then the conditions worth knowing by name, how to tell trembling from true weakness, what to expect at the vet, and what helps at home. If you want the wider picture of hind end problems, start with our overview of back leg problems in dogs and come back here.

The everyday causes to rule out first

Before anything medical, check the simple explanations, because they account for a lot of what owners see. Dogs shiver when they are cold, the same as we do, and a thin coated or lean senior dog will tremble on a tile floor or after a wet walk. Dogs also quiver with adrenaline: excitement at the door, nerves at the vet, fireworks, a stranger in the house. That kind of shaking starts with the trigger and stops when the trigger goes away.

Over-exertion is the other big one. In a dog with sore joints, this matters more than it sounds: high impact activities such as running or jumping should be limited because they can cause more inflammation and pain, and are better replaced with more controlled activities like leash walks.¹

If your dog's rear legs are quivering at rest but the walking, standing and stair work all look the same as last year, that is reassuring. Still mention it at the next check up, because some dogs are very stoic and will hide their pain until it becomes severe.²

Sore joints and tired muscles: the most common reason

Osteoarthritis, also called degenerative joint disease, is a progressively worsening inflammation of the joint caused by the deterioration of cartilage, the smooth cushioning layer inside a joint.² Any joint can be affected, but the condition most commonly affects the limbs and lower spine.²

Owners often notice these signs of osteoarthritis: a stiff hind limb gait, a waddle or sway through the body, being unwilling or unable to jump up onto furniture or into the car, sitting with a leg straight or on one hip, and difficulty rising from lying down.¹ Loss of muscle mass over the limbs and spine is part of the same picture and is listed as one of the signs of osteoarthritis.²

The most common cause of arthritis in dogs is another orthopedic problem that came first, such as a torn cranial cruciate ligament (one of the stabilising ligaments inside the knee), osteochondrosis (a fault in the way joint cartilage develops in young dogs) or trauma, and cruciate tears in the stifles (knees) are one of the joint injuries that can lead to arthritis.¹ Hip dysplasia, a poorly fitting hip joint, is the other: a prior diagnosis of elbow or hip dysplasia predisposes a dog to arthritis, and among dogs having cruciate ligament surgery, 74.0% of those with hip dysplasia showed X-ray evidence of osteoarthritis.²³ Risk also tilts toward certain dogs: osteoarthritis is a common problem in dogs, particularly in seniors and large breeds,² and young large breed dogs with developmental bone disease and older, overweight large breed dogs are commonly affected.¹

If this sounds like your dog, we go deeper into the pain side of the picture in our guide to arthritis pain and trembling hind legs.

Less common causes worth knowing by name

Beyond joint pain, a short list of spinal and whole body problems can show up as shaking or weak back legs, and it helps to know their names before the vet says them.

Intervertebral disc disease (IVDD). It is a neurologic condition in which the protective material around the spinal cord has changed, and the result can be pain, dysfunction or paralysis.⁴ It is a common source of back pain in dogs, especially older dogs but also younger dogs of predisposed breeds.⁵ What an owner sees can be subtle at first: at times the dog may appear to walk with a wobbly gait, and it may look like they are battling weakness in the rear.⁵ Type I disc disease, where disc material bursts out suddenly, is very common, especially among Dachshunds, French Bulldogs, Beagles and Shih Tzus,⁶ while Type II, where the disc slowly bulges instead, is more common in larger breeds.⁶ Discs in the very lowest part of the back count too: the type of IVDD depends on which part of the spinal cord is affected, and sacral IVDD involves the area near the dog's tail.⁴

Degenerative myelopathy (DM). This is a disease that affects the spinal cord in dogs, causing progressive muscle weakness and loss of coordination, usually starting in the hind limbs of older dogs.⁷ It is an inherited neurologic disease typically affecting dogs around eight years of age or older.⁷ The clinical signs often start in one hind limb and then progress to include both, and scuffed toenails on the hind limbs are one of the signs to watch for.⁷

Things outside the legs entirely. When a dog develops new tremors, a vet does not only look at the legs. In a dog with a new onset of muscle tremors, the veterinarian will first perform blood tests and a urine test to rule out medical conditions that may cause nerve related signs, such as liver disease or kidney disease.⁸ They may also test for infectious diseases.⁸ Infections that affect the joints, such as Lyme disease, are on the list of osteoarthritis risk factors.² And if you think your dog has eaten something they should not have, do not wait and watch. Call the vet or an emergency line straight away.

Shaker syndrome is a different thing, and probably not your senior dog

Shaker syndrome is a condition that involves generalized head and body tremors in dogs, also called steroid-responsive tremor syndrome or idiopathic generalized tremor syndrome, meaning tremors with no identified cause.⁸ You may hear it called "Little White Shaker Syndrome" because it is most common in small-breed white dogs, such as the Maltese, West Highland White Terrier and Bichon Frise,⁸ though any color and size of dog is susceptible.⁸

The timing is the giveaway. Affected dogs typically develop tremors during early adulthood, at one to two years of age.⁸ In many dogs the tremors worsen with excitement and exercise, and may improve or completely resolve when the dog is resting or sleeping.⁸ Most dogs are normal except for the tremors.⁸ So if your eleven year old Labrador's back legs quiver while his head and front end are rock steady, this is not the explanation. It is worth knowing anyway, because it is the first thing that comes up when people search why dogs' back legs shake.

Is it trembling, or is it real weakness?

The useful question is whether the back end is just shaky or is actually failing, and you can gather most of that answer at home in a week. Watch for these, and write down what you see:

• When it happens. Only when standing, or also while lying down and asleep?
• One leg or both.
• Nails. Look for scuffed toenails on the hind limbs.⁷
• Dragging. Dogs with IVDD may limp, drag their legs, or hunch their back.⁴
• Floors and stairs. Slipping on tile or laminate, hesitating at the bottom of the stairs, needing a run up to get onto the sofa.
• Getting up. Stiffness, lameness, limping or difficulty getting up² is a classic early pattern.
• Balance. Looking drunk while walking is listed as a sign of IVDD.⁴
• Muscle over the hips. Run both hands over the back end weekly. Loss of muscle mass over the limbs and spine is one sign of osteoarthritis, a condition that can be hard to spot early.²
• Toileting. Difficulty getting into a position that lets them poop, and pressure on the spinal cord making it hard to urinate or pass a bowel movement⁴ both matter, as does incontinence.⁵

When shaking back legs need a vet the same day

Some signs are not a "mention it at the next appointment" situation, they are a today situation. Get seen urgently if your dog's back legs are shaking and any of these are true:

• They cannot walk. "All of these symptoms require immediate veterinary attention," says Dr. Amy Attas. "The symptom that is an absolute emergency is if the dog is unable to walk."⁴
• It came on suddenly. Sudden hind leg collapse or paralysis is an emergency; we cover what to do in the first hours in our guide to a dog who suddenly cannot walk.
• They cried out, or the back is arched. You might see your dog arching their back to try and relieve the compression on the spine and make themselves more comfortable.⁴
• They have lost feeling in the feet. Dogs that become paralyzed and have also lost pain sensation are considered an emergency.⁶
• They are vomiting, collapsing, have pale gums, or you suspect poisoning.

Time counts with spinal problems. If you notice limping, leg dragging or a hunched back, bring your dog to your vet immediately to avoid further injury or loss of function.⁴ The sooner the vet examines your dog and administers treatment, the better your dog's chances of recovery.⁴ If your dog is both shaking and struggling to move the back end at all, read our guide on a dog who cannot move their back legs and is shaking on the way to the appointment.

What to expect at the vet visit

Expect a hands on exam of both the joints and the nerves, then bloodwork and imaging if the exam raises questions. Your vet will perform a full physical examination, including feeling your dog's joints and assessing their range of motion.² Examination of the bones and joints often shows pain on manipulation, grinding during range of motion, limited range of motion and swelling, and patients often limp or have a stiff gait.¹ On the nerve side, the first step is a neurologic examination by a veterinarian, a check of reflexes, balance and sensation.⁶

For imaging, your veterinarian may recommend X-rays of the affected joints, which help rule out other conditions that cause similar symptoms and let them evaluate the degree of damage.² X-rays have limits for discs: they confirm IVDD only 60 percent of the time, so the preferred imaging techniques are MRI or CT.⁶ That is when a specialist comes in. For dogs with more than mild pain, a referral to a veterinary neurologist may be recommended.⁵

If degenerative myelopathy is on the table, be ready for a process rather than one test. There is no specific test to diagnose DM while a patient is living, and several tests may need to be performed to rule out other potential spinal cord diseases.⁷

Before you go, do two things. Film your dog on video: standing still for thirty seconds, walking away from the camera on a flat non-slip surface, and getting up from lying down. Shaking is often shy at the clinic. Second, bring a one page diary: when it started, what time of day it happens, how far they walk before it shows, which leg, and anything new with stairs, toileting or sleep.

Day to day support at home

The management list for dogs losing hind end function includes using rugs, carpets or yoga mats on hardwood or tiled surfaces, adding pet ramps or steps where necessary, using a sling or harness to assist with walking and standing, wearing booties to decrease damage to scuffed paws, maintaining a healthy weight, physical therapy, and addressing any factors, like arthritis, that may also contribute to mobility issues.⁷

A few practical notes on each:

• Traction. Runners down the hallway, mats at the food bowl and by the door, and nails kept short.
• Ramps over stairs. Especially off the deck and into the car.
• Warmth and bedding. A thick orthopedic bed off the cold floor, and a coat for winter walks.
• Shorter, more frequent walks. Three ten minute flat walks beat one long one. Low impact consistent exercise is good to help build the muscles around the joints and will eventually promote joint stability.¹
• Weight. A slender body weight is by far the most critical aspect of arthritis management.¹
• Rehab. Animal rehabilitation such as range of motion exercises, therapeutic exercises and water based therapy including an underwater treadmill and swimming helps improve joint mobility, increase muscle mass and improve exercise endurance.¹ Ask your vet or a rehab vet for a home program: sit to stands, slow figure eights and controlled leash walking are the usual starting points. On a treadmill, set the speed and keep it consistent rather than choosing it at random, since hind leg joints move through a greater range as walking speed increases.⁹
• Gentle massage over the thigh and hip muscles after walks, as long as it does not make your dog flinch or move away.

For dogs who need more hands on help through the day, our guide to looking after a dog with weak back legs covers lifting, slings, hygiene and routine.

Where a rear support wheelchair fits in

A rear support cart takes the dog's back end weight off the legs, so a dog with weak hind limbs can keep moving without their legs trembling under full body weight. It is support, not treatment: it does not fix a joint or a disc, and it works alongside your vet's plan rather than instead of it. Veterinary management lists for dogs losing hind limb function include considering a wheelchair to support the hind limbs,⁷ and after spinal cord injury, if the dog's front limbs are strong enough, the vet may recommend a mobility device like a cart to help your dog get around.⁴

Signs a dog is ready for one: the back legs give out partway through a normal walk, you are using a towel or sling under the belly most days, the dog is enthusiastic but the back end will not keep up, or the quivering is now constant whenever they stand.

The OldPal Rear Support Dog Wheelchair is our one wheelchair, made for dogs with weak or failing back legs. The padded harness carries weight through the hips and chest rather than the spine, every strap adjusts, and the frame is set so the back legs hang free or lightly brush the ground, which means a dog who can still move their legs keeps using them. Dogs can squat and go to the bathroom while in the chair. The frame is lightweight aluminum with all-terrain wheels and adjusts in height within its size range.

Sizing comes down to one measurement: rear leg height, from the top of the hip straight down to the toe pad, with your dog lying on their side and the leg at its natural bend. Five sizes, Mini through XL, cover 3 to 27 inches. Use the measuring guide and fit finder, or email a photo and your measurement to help@oldpalpets.com and a person will check it with you. If the size is wrong, our Fit Guarantee lets you exchange the frame for the one that fits. Mini, Small and Medium arrive within 1 to 2 weeks of ordering, Large and XL within 2 to 3 weeks. We ship within the continental US.

Introduce the chair slowly. Harness on in the house for a few minutes with treats, then the frame attached for a short indoor walk, then five or ten minutes outside on flat ground, building up over a week or two. Supervise every session at first, check for rubbing under the straps, and keep out of chair time for rest, rehab exercises and sleep.

Tracking it week to week

Keep a simple log, because what matters is the trend, not today. Dogs have bad days after a long walk or a cold night, and one shaky evening is not a decline.

Once a week, in the same place and at the same time of day, record three things: a thirty second video of your dog standing and walking away from the camera, the distance or minutes they walked comfortably, and how long they can stand still before the trembling starts. Add a note about stairs, slipping and toileting.

That log tells you which story you are in. Joint disease is usually slow: osteoarthritis is a progressive disease and there is no known cure,² but medical management will allow most dogs to live a long and active life.¹ Degenerative myelopathy causes gradual muscle wasting and loss of coordination in the hind limbs, and then progresses to an inability to walk after six to twelve months, though routine physical therapy may delay the progression.⁷ Any sharp change from one week to the next, especially a sudden one, is a call to the vet rather than another week of watching.

Frequently asked questions

Related guides

• Shaking back legs in older dogs
• Hind leg arthritis in dogs
• When a dog will not put weight on a back leg

Sources