Home Neurological Problems Degenerative Myelopathy

Degenerative Myelopathy in Dogs

By the Dog Health Handbook team · Updated · Fact-checked against current veterinary references (see sources)

Key takeaways

  • DM is a slow, painless spinal cord disease that weakens the back legs of older dogs.
  • It usually starts at 8 or older, most often in German Shepherds, Corgis and Boxers.
  • The gene test shows risk, not the disease itself.
  • Most dogs can't walk within about 6 to 12 months of the first signs.
  • Physical therapy, nursing care and a cart help keep dogs mobile and comfortable.

Table of Contents

Research Signs and stages Breeds and gene test Diagnosis Treatment Life expectancy FAQ Sources

Brain, Spine and Nerve Quicklinks

Neurological Problems IVDD Degenerative Myelopathy Vestibular Disease Stroke and FCE Dementia Seizures

Degenerative myelopathy (DM) is a slow, painless disease of the spinal cord in older dogs. It causes gradually worsening weakness and wobbliness in the back legs, and eventually paralysis.1,2,3 It usually starts at 8 years or older, at an average age of about 9.4,1,5 It's most common in German Shepherds, Pembroke Welsh Corgis and Boxers, but it's been confirmed in about 30 breeds.4,6 DM is linked to a mutation in the SOD1 gene, the same gene involved in some forms of ALS in people.7,2 There's no cure, and there's no test that confirms DM in a living dog. Vets diagnose it by ruling out other causes.8,9 Most dogs lose the ability to walk within about 6 to 12 months of the first signs.10,11,1 Physical therapy, good nursing care and a wheelchair can keep dogs mobile and comfortable for longer.12,8,10

See your vet if your older dog:

  • Scuffs its back toenails, knuckles its back paws or sways when walking1,10
  • Has trouble getting up, or its back end seems weak or unsteady10

Go the same day if weakness comes on suddenly or your dog seems to be in pain. DM is slow and painless, so these point to another problem, such as a slipped disc.13,11

What the Research Says

  • The gene test shows risk, not disease. Almost all confirmed cases carry two copies of the SOD1 mutation, but many dogs with two copies never develop DM.4,14,5
  • The decline takes about a year. In a 2025 Zurich study of 39 dogs, the median time from first signs to losing the ability to walk was about 9 months. The median time to euthanasia was 12 months.11
  • Physiotherapy may help. In a 2006 Swiss study, dogs given daily intensive physiotherapy lived longer (a mean of 255 days) than dogs with none (55 days). The study was small, and a 2025 study didn't find a clear benefit.12,11
  • Gene-silencing is being tested. In a 2026 pilot, an RNA-targeting therapy injected near the spinal cord was well tolerated and lowered SOD1 levels in the spinal cord. All 4 treated dogs still got worse.15

Signs and Stages of DM

Early DM is often mistaken for arthritis or hip dysplasia.6,13 Unlike arthritis, dogs with DM have trouble knowing where their feet are, and they don't seem to be in pain.13,1 The disease moves through stages:5,1,10

StageWhat you see
1. EarlySwaying back end, scuffed back toenails, knuckling, crossing the back legs, often worse on one side. Still walking.
2. Back-leg weaknessTrouble rising, falling, needing help on stairs, losing muscle in the back legs
3. Back-leg paralysisCan't walk without support or a cart. Loss of bladder and bowel control may begin.
4. LateWeakness spreads to the front legs, then trouble swallowing and breathing

DM is usually described in 4 stages. We didn't find a published 5-stage scheme.5 Small dogs tend to progress more slowly and are easier to care for.14,1

Breeds and the DM Gene Test

DM has been confirmed by spinal cord examination in about 30 breeds.4 These include:

  • German Shepherds, Pembroke and Cardigan Welsh Corgis, Boxers and Rhodesian Ridgebacks
  • Chesapeake Bay Retrievers, Bernese Mountain Dogs, Golden Retrievers, Labrador Retrievers and Siberian Huskies
  • Poodles, Pugs and Collies

The DNA test looks for the SOD1 mutation. Results mean:4,14

  • Normal (N/N): very unlikely to develop DM
  • Carrier (A/N): one copy. Rarely affected, but can pass it on.
  • At risk (A/A): two copies. Almost all confirmed cases are A/A, but many A/A dogs never show signs.

Bernese Mountain Dogs can carry a second SOD1 mutation, so they need testing for both.4,14 An A/A result in a dog with signs supports a DM diagnosis but doesn't prove it. A normal result makes DM very unlikely.5,1 Breeders use the test to avoid producing at-risk puppies.4

How DM Is Diagnosed

DM can only be confirmed by examining the spinal cord after death.9,8 In a living dog, a "presumptive" diagnosis is based on:2,8,9

  • Typical slow, painless signs in an older dog
  • An A/A gene test result
  • MRI or myelography, and sometimes a spinal fluid test, to rule out look-alike diseases

The look-alike diseases include slow disc bulges, tumors, spinal inflammation and orthopedic problems. Some of these are treatable.2,6 Disc bulges are common in older large dogs and can occur alongside DM.11 Researchers are testing new markers, including a spinal fluid protein that was about 80% sensitive and 94% specific for DM in one study. These aren't yet routine.16,17

Treatment and Care

No medicine, steroid or supplement has been shown to slow DM.2,8,6 Care focuses on keeping your dog moving and comfortable:10,1,18

  • Physical therapy and daily walks: controlled exercise and range-of-motion work12,19,10
  • A healthy weight, to make it easier to support the back end
  • Grip and support: rugs on slippery floors, ramps, a sling or rear harness, and booties to protect scuffed toes
  • A wheelchair (cart) once the back legs fail
  • Nursing care: padded bedding and turning every 4 to 6 hours to prevent pressure sores; emptying the bladder about 3 times a day if needed; watching for urine infections
  • Treating arthritis or other painful problems that make things worse

Research is active. A multicenter US trial is testing a drug approved for human ALS, and gene-silencing therapies are in early testing.20,15 Stem cell treatments are experimental. A small 2023 study couldn't separate their effect from intensive rehabilitation.19

Life Expectancy and When to Say Goodbye

Estimates vary. Most dogs can't walk within about 6 to 12 months of the first signs. Many are put to sleep within about a year of the first signs. Older reference figures give 1 to 3 years after diagnosis, but in a 2025 study the median was about 6 months after diagnosis.10,11,1,2 With a cart and good nursing, some dogs live longer, but the disease eventually affects the front legs and breathing.10,8

DM isn't painful, so the decision usually depends on quality of life. Large dogs are often put to sleep when they can no longer walk.1 A quality-of-life scale can help. It scores Hurt, Hunger, Hydration, Hygiene, Happiness, Mobility and More good days than bad.21,22 Talk to your vet as signs progress.

See also neurological problems in dogs, IVDD in dogs and hip dysplasia.

Frequently Asked Questions

Is degenerative myelopathy painful for dogs?

No. Dogs with DM don't seem to feel pain from the disease itself.

How fast does degenerative myelopathy progress?

Most dogs lose the ability to walk within about 6 to 12 months of the first signs.

Is walking good for a dog with DM?

Yes. Regular controlled exercise and physiotherapy may help dogs stay mobile longer.

At what age do dogs get degenerative myelopathy?

Usually at 8 or older, with an average of about 9.

Can a carrier dog get DM?

Rarely. Almost all affected dogs carry two copies of the mutation.

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Sources and further reading

This article was written and fact-checked on October 26, 2026 against current veterinary references and specialist guidelines:

  1. University of Missouri Veterinary Health Center. Degenerative Myelopathy. MU Veterinary Health Center, 2016, modified October 2025.
  2. Thomas WB. Degenerative Diseases of the Spinal Column and Cord in Animals. Merck Veterinary Manual (professional version), reviewed October 2021, updated April 2025.
  3. Gardiner J. Degenerative Myelopathy. UC Davis Veterinary Neurology Service, September 2019.
  4. Orthopedic Foundation for Animals. Degenerative Myelopathy. OFA, accessed October 2026.
  5. DogWellNet staff. Degenerative Myelopathy: Diagnosis and Inheritance. DogWellNet (International Partnership for Dogs), revised November 2021.
  6. Flegel T. Degenerative Myelopathy in Dogs: Current Issues on Diagnosis, Pathogenesis and Treatment. WSAVA World Congress, Geneva, 2010 (IVIS).
  7. ScienceDaily (University of Missouri). Gene Mutation for ALS Found in Dogs (title paraphrased). ScienceDaily, January 23, 2009 (reporting Awano T et al. PNAS 2009).
  8. University of Missouri College of Veterinary Medicine. DM: Degenerative Myelopathy. MU CVM research, accessed October 2026.
  9. AKC Canine Health Foundation. Exploring New Tools for Degenerative Myelopathy Diagnosis. AKC CHF, November 2021, updated June 2025.
  10. Cornell University College of Veterinary Medicine. Degenerative Myelopathy. Cornell Riney Canine Health Center, accessed October 2026.
  11. Sebestyen P, Kowalska ME, Golini L. Survival and deterioration time of walking abilities in dogs homozygous for the SOD1 gene mutation with and without thoracolumbar intervertebral disc protrusion. Front Vet Sci 2025;12:1555889. doi:10.3389/fvets.2025.1555889
  12. Kathmann I, Cizinauskas S, Doherr MG, Steffen F, Jaggy A. Daily controlled physiotherapy increases survival time in dogs with suspected degenerative myelopathy. J Vet Intern Med 2006;20(4):927-932. doi:10.1892/0891-6640(2006)20[927:DCPIST]2.0.CO;2
  13. Thomas WB. Disorders of the Spinal Column and Cord in Dogs. Merck Veterinary Manual (pet owner version), reviewed February 2018, updated September 2024.
  14. UC Davis Veterinary Genetics Laboratory. Degenerative Myelopathy (DM). UC Davis School of Veterinary Medicine, accessed October 2026.
  15. Olby NJ, Panek W, Galifi C, et al. Development and pilot testing of U1 Adaptor therapy targeting SOD1 expression for dogs with degenerative myelopathy. J Vet Intern Med 2026;40(1):aalaf072. doi:10.1093/jvimsj/aalaf072
  16. Toedebusch CM, Bachrach MD, Garcia VB, Johnson GC, Katz ML, Shaw G, Coates JR, Garcia ML. Cerebrospinal Fluid Levels of Phosphorylated Neurofilament Heavy as a Diagnostic Marker of Canine Degenerative Myelopathy. J Vet Intern Med 2017;31(2):513-520. doi:10.1111/jvim.14659
  17. Kowal JB, Verga SA, Pandeya SR, Cochran RJ, Sabol JC, Rutkove SB, Coates JR. Electrical Impedance Myography in Dogs With Degenerative Myelopathy. Front Vet Sci 2022;9:874277. doi:10.3389/fvets.2022.874277
  18. Williams K. Homecare for Paralyzed Pets. VCA Animal Hospitals, March 2024.
  19. Gouveia D, Correia J, Cardoso A, et al. Intensive neurorehabilitation and allogeneic stem cells transplantation in canine degenerative myelopathy. Front Vet Sci 2023;10:1192744. doi:10.3389/fvets.2023.1192744
  20. AKC Canine Health Foundation. AKC Canine Health Foundation Funds Groundbreaking Study to Evaluate Potential Treatment for Degenerative Myelopathy. AKC CHF news release, June 1, 2023.
  21. Hunter T, Downing R. Quality of Life at the End of Life for Your Dog. VCA Animal Hospitals, updated August 2024.
  22. Merck Veterinary Manual. The HHHHHMM Scale. Merck Veterinary Manual (after Villalobos AE, 2004).

About this article

Last updated : new page, written using the Merck Veterinary Manual, the University of Missouri, UC Davis, Cornell, OFA, IVIS proceedings and studies published 2006 to 2026.

This page is for general information and is not a substitute for an exam by your veterinarian.