Degenerative Myelopathy in Dogs: What Pet Owners Should Know

Degenerative myelopathy in dogs is a heartbreaking progressive neurologic disease that attacks the spinal cord. Also known as chronic degenerative radiculomyelopathy and canine degenerative myelopathy, the disorder causes the slow breakdown of the white matter in the spine.

DM is a common cause of paralysis in large breed, older dogs between the ages of 8 – 14 years-old. Younger dogs can be affected as well, but it’s rarely seen in canines under 5-years-old.

Dogs first show signs of wobbly hind legs and loss of coordination that progresses into weakness and paralysis. It later attacks the front legs and ultimately dogs succumb from organ failure.

The life expectancy of victims is 2-3 years. Some dogs pass away sooner at 1 year and others have been known to live for 5 years. It all depends how fast the disease advances.

The goal of this article is to make you familiar with the symptoms of DM, the DNA test, diet, treatments and good news about what you can do.

DM is close to my heart. The symptoms and the way it develops were nearly identical to the progression of the neurological disease that took my dog, Sophie. For that reason, I’ve tried to stay up-to-date about latest advances.

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What researchers know

DM was first classified as a disease in 1973. At the time, veterinarians thought it was a condition exclusive to German shepherds and for a while it was called German Shepherd Degenerative Myelopathy. Today we know many large dog breeds are prone.

We also know the symptoms are similar to a human disease called ALS (Amyotrophic Lateral Sclerosis), or Lou Gehrig’s disease. Much of the research has revolved around this idea, trying to duplicate the treatment of ALS patients to canines.

In 2009, scientists also discovered a genetic mutation in DM victims. The cause is a DNA mutation in a specific gene called SOD1. This development led to the development of a DNA test your dog can take.

Progression of the disease

DM slowly attacks a dog’s central nervous system by stripping away the protective coating called myelin. This leads to a breakdown of the white matter in the spine which controls movement.

As the white matter deteriorates, less commands about mobility are received from the brain to the limbs and fewer physical sensations are sent from the limbs to the brain. (I hope that makes sense.)

Dogs prone to the condition

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Here’s a list of the breeds deemed susceptible by the University of Missouri.  That doesn’t mean every dog will have the mutated SOD1 gene. It means these breeds have had the genetic mutation and “microscopic examination of spinal cords from deceased  dogs exhibited symptoms.”

• American Eskimo Dogs
• Bernese Mountain Dogs
• Borzoi
• Boxers
• Cardigan Welsh Corgi
• Chesapeake Bay Retrievers
• German Shepherd Dog
• Golden Retriever
• Great Pyrenees
• Irish Setters
• Kerry Blue Terriers
• Pembroke Welsh Corgis
• Poodle
• Rhodesian Ridgeback
• Shetland Sheepdog
• Soft Coated Wheaton Terriers
• Wire Fox Terrier

Symptoms of Degenerative myelopathy

I’ve broken down the signs of DM into common early symptoms and advanced stages. If your dog is suspected to have Degenerative myelopathy, they won’t have every symptom listed.

Here are common early symptoms:

• Weakness in the hind limbs that gets progressively worse
• Difficulty getting up from the floor
• Wobbly legs
• Walks by swaying the hips
• Worn down nails
• Knuckles under the paws. (The medical term for this is proprioception. It happens because a dog isn’t aware or can’t feel how they’re placing their paw on the ground.)
• Dragging the back feet
• Muscle loss in the back legs
• Tremors or spasms in the hind legs
• Paralysis in the hind end

Meet Skye

Photo courtesy of Skye’s family.

Skye was the treasured German shepherd of Dorri and Karol. I met the family when Skye had been diagnosed with DM for two years. I’ll be sharing their story throughout this post.

The first symptoms Skye showed were pretty typical for the disease.

One day, out of the blue, she stumbled down the front steps of her house. Dorri and Karol checked her for injuries, but she seemed fine. They chalked it up to the fact that Skye was becoming an old dog.

Not long after, Dorri and Karol noticed that Skye’s hind legs wobbled and crisscrossed when she walked around the house. They would get tangled and cause her to fall.

After six months Skye was paralyzed from her hind legs to the middle of her body. She was incontinent as well.

Advanced stages:

• The symptoms of weakness and knuckling move to the front limbs
• Urinary and fecal incontinence
• Muscle wasting
• Pneumonia
• Infection
• Organ failure

Most DM dogs go from being healthy to paralyzed within 6 months – 1 year from the onset of their symptoms. The advanced signs appear from 1 – 3 years, with some dogs surviving up to 5 years.

Here’s a video of a dog showing the early signs of DM. It was submitted by a devoted pet dad who wanted to help pet families.

A disease without pain

When DM starts it can resemble other conditions, like hip dysplasia, a ruptured disc, cancer or a spine infection. So, if you’re worried about getting an accurate diagnosis, here’s a clue to keep in mind.

Degenerative myelopathy is not a painful condition in the early stages. I like to think of this as an act of kindness from nature, but being pain free is an important unique aspect of the disease.

On occasion a dog can experience neuropathy as the nerves in their spine die. These pups tend to bite and chew on their paws, but they don’t show other signs of pain. If your dog experiences this problem, you can wrap the paws in gauze or add soft booties to protect them from injuries. You can also talk with your vet about medications and other treatments.

How veterinarians diagnose DM

Veterinarians make their diagnosis based on your dog’s symptoms and by ruling out other conditions, like the ones mentioned above.

The only precise way to diagnose the disease is by examining the spinal cord after an animal passes away.

If your vet suspects DM the diagnosis process will probably begin with a physical exam and a basic neurological exam. Blood work and X-rays are also routinely ordered.

Many dogs are then referred to a veterinary neurologist where they undergo a thorough neurological assessment along with a CT scan or an MRI. These powerful imaging tests examine the layers of the spine. They’re valuable tools to rule out other disorders.

A DNA test

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The gene mutation for DM was discovered during a research study conducted by the University of Missouri. It led to the development of a DNA test which has been a big benefit to vets and pet owners.

If your veterinarian suspects DM, you’ll probably be asked to order this test for your dog. The DNA test is inexpensive and can be ordered online through the Orthopedic Foundation for Animals (OFA). It’s done in your home with an easy to use swab of your dog’s cheek. Pet owners then mail the test to OFA for the results.

The test identifies whether or not your dog has two copies of the mutated SOD1 gene associated with Degenerative myelopathy. Unfortunately, it isn’t able tell you that your dog has an active case.

The test gives pet owners the following information:

1. At-Risk (A/A) – If your dog receives a test result of A/A, it means they’re in the highest risk category. It says your dog’s DNA has two mutated copies of the SOD1 gene associated with DM. If your dog is exhibiting DM symptoms, this test result will give your vet an important piece of information.  On the other hand if your dog is being tested because their breed is prone, an A/A score doesn’t mean they have a 100% chance of developing the disease. Not every dog with two mutated genes will have Degenerative myelopathy during their lifetime.
2. Carrier (A/N) – This test result means your dog was identified to have one mutated gene and one normal gene. Dogs in this category are less likely to develop DM, although the possibility is there.
3. Normal (N/N) – Dogs in this category were identified to have two normal copies of the gene. It means your dog is unlikely to develop DM, although it doesn’t rule out the possibility completely. Two dogs in the University of Missouri study with this result, went on to develop DM. This was probably due to other risk-factors in the breed.

Treatment, holistic care and nutrition

Unfortunately, no treatment will cure DM, but one study proved that daily physical therapy can increase the survival rate. If you choose to go this route, please work with a professional canine physical therapist.

Here are treatment options to consider:

• Physical therapy – Dogs work with a canine PT several times a week to maintain muscle strength and quality of life.
• Water therapy – Dogs love this type of rehab. Your dog and a canine aquatic specialist will do a series of exercises in a specially designed and heated indoor swimming pool. Water therapy keeps the leg muscles flexible and the core strong.
• Holistic veterinary care – Chris Bessent, DVM, MSOM, Diplomat of Oriental Medicine is the founder of Herbsmith Inc. Dr. Bessent treats DM dogs with electro-acupuncture. She likes this particular form of acupuncture because it sends a warm wave of electricity to a dog’s spine. She also prescribes omega-3 oil that comes from Krill for her DM patients because it nourishes the spine.

A special diet – R.M. Clemmons, DVM, PhD has spent most of his career researching DM. He developed a diet to stabilize the immune system and eliminate toxins. You can find Dr. Clemmons homemade diet and supplement recommendations on his website.

Skye’s rehab program

During her first year with Degenerative myelopathy Skye spent a lot of time in water therapy. It was great way to keep her muscles strong without overtaxing her body.

She loved being in the water so much her owners also took her to a friend’s house where she could splash and play in the pool.

If you choose to go this route, be sure to have a “dog swim vest” on your pet the entire time they’re in and around the water. And be sure to stay with them in the pool, at all times.

Unfortunately, accidental deaths have been reported because pet owners didn’t notice the gradual decline of their pet’s health.

Good breeding practices to prevent DM

Because Degenerative myelopathy is an inherited disease, victims can be limited through responsible breeding practices.

If you’re planning to add a puppy who’s prone to the disease, ask the breeder about the history of DM in the dog’s lineage.

Good breeders are proactive and remove a dog from the breeding pool when their DNA test shows they’re in the At-Risk category.

What you can do for your dog

DM is a sad diagnosis, but the good news is that you can make a big difference to your dog’s quality of life.

Here’s a list of activities to help:

• Take your dog for a daily walk. Dogs love the fresh air. Purchase a support harness to make walking easier and booties to protect the paws.
• Ask your vet for a hands-on lesson about how to express your dog’s bladder. Expressing is the best way to prevent urinary tract infections.
• Talk to your vet about gentle range-of-motion exercises you can do with your dog at home. In will help to maintain your dog’s muscle tone.
• Invest in a dog wheelchair or stroller or dog trailer for the time when your pet won’t be able to walk on their own. Dogs feel better when they can be mobile.
• Make sure your pup has a good orthopedic bed to prevent pressure sores.
• If your dog is immobile, be sure to gently turn your every 2-4 hours. Lying in one position for too long increases the chance for the skin to breakdown.
• Show your pup love and affection. You mean the world to them.

How Skye spent her time

Skye’s day began with a sponge bath by one of her doting owners. It kept her fur clean and free from urine that dripped overnight. Then Dorri or Karol would take her outside to express her bladder. A support harness helped them lift and move her.

After breakfast there were visits to the pool or to a holistic veterinarian for acupuncture treatments and laser therapy.

In the afternoon Skye got to do one of her favorite activities. She loved her daily walks and being outdoors. A dog wheelchair allowed her to continue this ritual as her health declined and after she could no longer walk.

Later when DM made it hard for her to sit up on her own, Skye’s family transitioned to a dog stroller/trailer. It let her enjoy the sights and scents of her neighborhood and say hi to the people on her street. Skye lived with Degenerative Myelopathy for more than 3 years.