Degenerative Myelopathy

Degenerative myelopathy (DM) in dogs: what it means

Degenerative myelopathy (DM) is an incurable disease that causes a slow deterioration of the spinal cord and eventually leads to paralysis. Unfortunately, there’s no cure. However, intensive physical therapy has been shown to slow progression.

Some supplements promoted online, such as aminocaproic acid and N-acetylcysteine, haven’t been shown to be effective in clinical experience or research studies, so Remedy doesn’t include them in DM care recommendations.

In DM, nerve fibers in the spine called axons die off. This process is similar to the human disease amyotrophic lateral sclerosis (ALS), also known as Lou Gehrig’s disease. The cause of this axon death is unknown, but DM has been associated with a genetic defect (the SOD1 mutation). A test for this mutation exists, which we’ll cover in the diagnostics section below.

Which dogs are at risk for degenerative myelopathy

Degenerative myelopathy is usually diagnosed in middle-aged and older dogs. Any dog can develop DM, but German Shepherds, Boxers, Rhodesian Ridgebacks, Chesapeake Bay Retrievers, and Corgis appear to be at increased risk compared to other dogs. When DM occurs in Corgis, it tends to appear later in life, often after age 11.

Degenerative myelopathy symptoms & Progression

In the early stages of degenerative myelopathy, dogs are uncoordinated in their rear legs. They may trip over their feet or scuff their toenails. As this progresses, some dogs may stand on the tops of their feet, or their legs may cross and become tangled as they walk.

That said, DM isn’t painful.

Over about 6–12 months, many dogs with DM become paralyzed in their back legs. The disease often progresses more slowly in Corgis, with time to paralysis averaging 19 months.

Paralysis often occurs gradually, but some dogs show a “stair step” pattern, where they’re stable for long periods with sudden drops in function.

As dogs with DM become paralyzed in their back legs, they may also lose bladder and bowel control, leading to incontinence. Dogs who are incontinent may need assistance emptying their bladder. If your dog needs help relieving themselves, ask your veterinarian for instructions on expressing their bladder.

Some pet parents choose euthanasia when their dog is no longer able to walk. Others choose to have their dog fitted for a wheelchair. This decision is very personal. Talk to your veterinarian about your situation and what feels right for you and your dog.

If you choose to continue care after their back legs are paralyzed, the disease will eventually progress to cause front limb paralysis and then affect the brainstem. This can cause difficulty breathing, difficulty staying awake, difficulty swallowing, and eventually death. Remedy recommends euthanasia once your dog’s front legs are significantly affected.

Diagnosing degenerative myelopathy

It’s a common misconception that a dog can be diagnosed with degenerative myelopathy by an exam alone, or that all older dogs with incoordination and weakness have DM. Degenerative myelopathy cannot be diagnosed this way. It takes an extensive set of tests to be confident your dog has the disease.

DM symptoms can be identical to many other spinal diseases, such as a slipped disc, infection, or a spinal cord tumor. Some of these other diseases are treatable, which is why it’s important to look for other causes before deciding a dog has DM.

Spinal X-rays, MRIs, & spinal taps

Degenerative myelopathy testing may include spinal X-rays, MRI, and a spinal tap to help rule out other spinal conditions that can look similar, such as a slipped disc, infection, or a spinal cord tumor. If a dog truly has DM, these tests are expected to be normal because they aren’t finding another cause for your dog’s symptoms.

Genetic testing (SOD1 mutation)

You can screen for the SOD1 mutation through the Orthopedic Foundation for Animals, which offers cheek swab test kits you can order directly. This test is also commonly included in over-the-counter genetic health screening tests, such as Wisdom Panel Premium. Remedy can also help run this test during your appointment.

Interpreting the genetic screen

Having two copies of the SOD1 mutation has been associated with degenerative myelopathy. However, two copies don’t confirm that your dog has DM. The lifetime likelihood of developing DM with this genetic makeup isn’t fully known. Because of that uncertainty, it’s important to rule out other conditions that can cause similar signs through appropriate testing, such as an MRI.

Having one copy, or no copies, of the mutated gene strongly suggests your dog does not have degenerative myelopathy, and your veterinary team should continue looking for other causes of your dog’s symptoms.

This genetic test also matters in dog breeding because it can help reduce the spread through bloodlines. For that reason, dogs with any SOD1 mutation (one or two copies) are recommended to be spayed or neutered. If you learn your dog has one or two copies of the mutated gene, it’s also important to inform your breeder.

Treatment & supportive care for degenerative myelopathy

Physical therapy

Physical therapy is the only treatment that has been shown to help dogs with degenerative myelopathy. Outcomes are best with higher intensity and more frequent sessions, so a structured program done as often as possible, ideally daily, is recommended. If you’d like a referral to a certified canine rehabilitation therapist, ask your veterinarian.

Supplements

Many supplements, including vitamins and antioxidants, are promoted online for degenerative myelopathy. However, these therapies haven’t proven helpful, and Remedy doesn’t recommend them at this time.

Diet

Some diets are promoted online as treatments for degenerative myelopathy. Like supplements, these diets haven’t proven effective, and Remedy doesn’t recommend them at this time. If you’d like to explore diet therapy, a board-certified veterinary nutritionist can help create a balanced plan for your dog. If you’d like a referral, Remedy will be happy to connect you.

Stem cell therapy

Stem cell therapy is sometimes discussed for degenerative myelopathy, but there are only limited reports to date. The cells are grown from material collected through a surgical procedure, and for the best chance of success, they must be injected around your dog’s spinal cord. Because this approach is experimental and invasive and hasn’t yet been proven effective, pet owners should consult carefully with a veterinarian before considering it.

Monitoring at home & when to contact your veterinarian

Skin irritation & pressure sores

Wetness and pressure are the two most common causes of skin problems in a dog who cannot walk, and both can worsen quickly if they are missed.

  1. Start with wetness: After any urinary accident, use a waterless shampoo and soft towels to clean and dry the skin. Pay close attention to the groin area between your dog’s legs, since moisture often builds up there.

  2. Check for pressure: Look for pressure sores every day. These can occur anywhere, but they’re most common where bone is close to the surface, such as the hips, shoulders, and elbows. Early pressure sores may look like mild redness, but they can progress quickly to dangerous open wounds. Contact your veterinarian with any concerns.

Urinary tract infections

Urinary tract infections are very common in pets with spinal problems. Each time your dog urinates, check the urine for changes in color or smell. If your dog urinates in grass, blot the spot with a white paper towel to evaluate the color. Concerning changes can include urine that looks pink or red, brown or unusually dark, cloudy, or has a very strong, foul smell. If you have concerns, contact your veterinarian.

Toenail & foot health

As incoordination progresses, many dogs with DM scuff their nails and may injure their feet. Boots that may help protect your dog’s feet from injury can be purchased at retailers such as REI or through online pet mobility retailers.

Boots vary widely in fit and style, so it may take a couple of tries to find a pair that works well for your dog. Choose a retailer with a good return policy so you can test fit at home. To help prevent moisture buildup and infections, make sure your dog spends at least half the day with boots off.

Emergency signs for dogs with degenerative myelopathy

If your dog has any of the following signs, emergency veterinary care immediately.

  • Difficulty breathing

  • Difficulty staying awake, or your dog cannot be roused

  • Difficulty swallowing, including trouble eating or drinking

  • New or severe weakness in the front legs

As symptoms progress, dogs with DM will typically stumble or walk on the tops of their feet.

The loss of blue color at the edges shows the degeneration of the spinal cord in dogs with DM.