Degenerative Myelopathy in Dogs: Signs, Stages and What Helps

Your dog's back legs are going, and someone has said the words "degenerative myelopathy." Here is the short version: degenerative myelopathy (DM) is a disease that affects the spinal cord, resulting in slowly progressive hind limb weakness and paralysis.¹ Dogs with the condition are usually older than 8 years of age and slowly start to display nonpainful incoordination and weakness of the hind limbs.² It acts similarly to Lou Gehrig's disease, or ALS (amyotrophic lateral sclerosis), in humans.³

But wobbly, weak back legs have plenty of other causes. According to canine neurology expert Dr. Roger Clemmons, only about 25% of German Shepherds showing these signs actually have degenerative myelopathy, and the rest have potentially treatable conditions.⁴ That is why a thorough workup is worth doing. Start with our overview of back leg problems in dogs, then read on.

What is degenerative myelopathy in dogs?

DM is a spinal cord disease in which the protective myelin around nerve fibers is gradually destroyed, so the nerves lose their ability to transmit signals, leading to weakness and paralysis that starts in the hind legs.⁴ The symptoms result from degeneration of the white matter of the spinal cord, the part that carries signals between the brain and the body.¹ The exact cause of DM is unknown.¹

The important thing for owners: degenerative myelopathy is not a painful disease.⁵ Your dog is not suffering silently. Their legs simply stop doing what they are told.

Early signs owners notice first

The first signs of DM can be subtle, like your dog dragging a rear foot, having a wobbly gait, or taking a wrong step here or there.⁴ The clinical signs often start in one hind limb and then progress to include both.³

Watch for these:

• The hind paws "knuckle" or turn under so that the dog walks on its knuckles, especially when turning.¹
• The dog's hindquarters appear to sway when standing still.¹
• The hind feet seem to scrape the ground when walking, and sometimes the top surface of the feet become hairless and irritated from repeated trauma.¹
• The dog falls over easily when pushed from the side.¹
• The dog has difficulty getting up from a lying position.¹

Keep a simple diary: date, what you saw, which leg. It is the most useful thing you can hand your vet.

Why most wobbly back legs are not DM

Rear end weakness can be caused by many other problems besides DM, and a good number of them are treatable.⁴ The usual suspects:

• Arthritis and hip dysplasia. In its early stages, the symptoms of DM resemble those of osteoarthritis, which often occurs secondary to hip dysplasia in many large breed dogs, making diagnosis challenging.¹
• Disc disease (IVDD). It is a common cause of spinal cord disorders in dogs, especially small breeds like Dachshunds, Beagles, Shih Tzus, Lhasa Apsos, and Pekingese.²
• Degenerative lumbosacral stenosis. Signs may include difficulty using the hind legs, tail weakness, and incontinence, and dogs often experience pain when the lower back is touched or moved.²
• FCE, where a piece of cartilage, likely from a disc between the vertebrae, blocks blood flow to the spinal cord.² It typically begins after jumping or running and causes a sudden, nonpainful change in the dog's gait.²
• Spinal tumours and infections, which your vet will also look for.

Two clues separate them. Pain: if the dog appears to be in pain, there may be another condition such as arthritis complicating the picture.¹ And foot placement: dogs with degenerative myelopathy have difficulty sensing and placing their feet normally whereas arthritic dogs do not.²

Sudden weakness or paralysis is an emergency. Go now, not tomorrow. If surgery is delayed for more than 24 hours after pain perception is lost, the chances of recovery decrease.²

How vets diagnose it

DM is a diagnosis of exclusion, meaning your vet only makes the diagnosis after other causes of rear end weakness have been ruled out.⁴ Testing may include a neurological exam, blood work, X-rays, MRI or CT scan, and spinal fluid analysis.³

Genetic testing can show whether your dog carries one or two copies of the variants linked to DM, but there is no specific test that can diagnose the disease in a living dog, so vets must rule out other spinal cord problems first.³ For dogs showing clinical signs with a presumptive diagnosis of DM, an "affected" (A/A) test result can be used as an additional tool to aid in the diagnosis.⁵ Not all dogs testing as A/A have shown clinical signs of DM.⁵

Is degenerative myelopathy hereditary?

Largely, yes. DM is an autosomal recessive genetic disease, meaning a dog usually needs to inherit the faulty gene (SOD1) from both parents; inheriting one or two copies increases the risk of developing the disease.¹ Results come back in three main forms, plus an inconclusive "equivocal" result if the sample is poor: a normal (N/N) dog is unlikely to ever develop DM; carriers are far less likely to develop DM, but DM has been confirmed in a few carrier dogs; an A/A dog has two mutated copies and is at risk.⁵ Still, not all A/A dogs show signs, and DM is typically a late-onset disease.⁵

DM seems to be more common in some breeds, like Pembroke Welsh Corgis, German Shepherd Dogs, Boxers, Rhodesian Ridgebacks, and Chesapeake Bay Retrievers.⁴ If you breed, at-risk breeds should be tested for the SOD-1 mutation prior to breeding to avoid passing on the abnormal gene.¹

How it progresses

DM causes gradual muscle wasting and incoordination in the hind limbs, and then progresses to an inability to walk after six to twelve months.³ Over 6 months to 2 years after the onset of signs, progressive paralysis spreads to affect all limbs.⁶ Bladder and bowel function are usually normal in the early stages of DM, and urinary and fecal incontinence develop only as the disease progresses toward paralysis.¹ Survival time following diagnosis of DM in dogs can vary.⁴

Treatment and rehab: what actually helps

No effective drug treatment for DM exists, but staying active matters, since physical therapy has been shown to slow progression, preserve muscle mass, and prolong quality of life.¹ One study found that dogs with DM survived for longer if they received intensive physical therapy, and those dogs were able to walk significantly longer than dogs that received moderate or no physical therapy.⁴ It is important to avoid obesity, so diet and exercise (walking and swimming) are vital components of treatment, with the goal of maintaining the dog on its feet for as long as possible.¹

A realistic week looks like short flat walks several times a day, sit-to-stand practice on grippy ground, and gentle swimming or an underwater treadmill session if your rehab vet offers one.

Should you keep walking your dog?

Yes, within limits. Any dog with DM should be kept as physically active as possible for as long as possible.¹ Aim for short, frequent, flat outings rather than one long one. Stop when the back end starts knuckling badly, crossing over or dropping: fatigue makes every stumble worse. A support sling or rear-support harness lets you take weight off the back end on the way home.

Mobility gear and when to add a wheelchair

Management 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, and considering a wheelchair to support the hind limbs.³

Common signs owners are ready for a cart: daily knuckling, repeated falls, and lifting the back end to get out to the yard. The OldPal Rear Support Dog Wheelchair supports the back end so the front legs do the driving, with a padded harness that carries weight through the hips and chest rather than the spine. The back legs hang free or lightly brush the ground, and dogs can still squat to go to the bathroom in the chair. It comes in five sizes and is fitted by one measurement, rear leg height: check the size guide and fit finder, or email help@oldpalpets.com with a photo. Start with ten minutes indoors, then short familiar routes.

Day-to-day care at home

Rugs and runners on slick floors. Nails trimmed short so they catch less. Boots or paw protection for scuffed toes. Try soft bedding to prevent bedsores, which may result if your dog can't walk.⁴ Turn a dog who cannot reposition themselves, keep the back end clean and dry, hold weight steady, and lift with both arms under the chest and hips rather than hauling from the hips alone.

Frequently asked questions

Related guides

• Can degenerative myelopathy in dogs be cured?
• Treatment options and what they realistically do
• Choosing a wheelchair for a dog with degenerative myelopathy

Sources

Related guides

• Dog Can't Walk: Causes, Care and Next Steps
• Cushing's Disease and Weak Back Legs in Dogs: Why It Happens and What Helps
• Dog Back Legs Shaking: Causes and When to Worry
• Hip Dysplasia in Dogs: Signs, Diagnosis and Treatment
• Wobbler Syndrome in Dogs: Why the Neck Weakens the Back Legs