Degenerative Myelopathy in Dogs: What Happens and What Helps

Your dog has been diagnosed, or you suspect it: here is the plain version

Canine degenerative myelopathy is a fatal disease of the spinal cord in which nerve tissue breaks down over time.¹ It is inherited, follows a progressive course, and ultimately leads to the death of affected animals.² It is progressive and results in paralysis in dogs.³

If you already know where this is heading and you want to keep your dog upright and walking with support, start with our guide to a dog wheelchair for degenerative myelopathy.

What is degenerative myelopathy in dogs

Degenerative myelopathy, often shortened to DM, is an inherited disease passed on in an autosomal recessive way, and it affects many different dog breeds.⁴ Canine degenerative myelopathy has been associated with mutations in the superoxide dismutase 1 gene, known as SOD1, a gene that normally helps cells clear harmful waste products.⁵

Degenerative myelopathy is a late-onset disease, with signs usually appearing in older dogs at around eight years of age.¹

Some dogs that carried two copies of the SOD1 risk version of the gene did not develop clinical disease or the associated damage to nerve tissue, indicating that other factors in addition to the SOD1 mutation influence disease onset and progression.⁶

Does my dog have degenerative myelopathy, or is it something else?

An early DM sign is wobbliness and poor coordination in the back legs.⁶ This comes from damage to proprioception, the sensory system that tells a dog where its limbs are in space, and that damage is linked to the wobbly hind end seen early in degenerative myelopathy.⁶

Dogs with two copies of the SOD1 gene mutation and suspected degenerative myelopathy can also have a bulging spinal disc at the same time, which can cause similar signs.⁷

So rather than searching online for a verdict, track what you see. Note dates, which leg, and what surfaces cause trouble. Your vet can work with that.

How a a diagnosis of degenerative myelopathy in dogs is reached

In one documented case, scans of the spinal cord and tests of the fluid around it showed nothing abnormal,⁵ while DNA testing showed the dog carried two copies of the SOD1 mutation.⁵

We walk through that whole process step by step in our degenerative myelopathy dog diagnosis guide.

Which breeds are affected by degenerative myelopathy

The SOD1 mutation linked to degenerative myelopathy shows up in many breeds but at very different rates, with testing in Italy finding it most often in Pembroke Welsh Corgis (55.49%) and least often in Poodles (6.32%) and Australian Shepherds (7.14%).¹ In a Uruguayan study, the DM-related version of the gene had a frequency of 0.16 in the Pit Bull Terrier and 0.52 in the Boxer breed.² German Shepherds are also well represented: in one clinical group of dogs with the mutation, the most common breed was the German Shepherd.⁷

Mixed breed dogs can also develop degenerative myelopathy, as shown by a confirmed case in an 8-year-old male neutered Boston terrier-French bulldog mix that carried two copies of the SOD1 mutation.⁵

If you breed, or you are choosing a puppy, testing is the lever. Carrier dogs, meaning dogs that carry the gene change, can be identified so they are not bred from, reducing how often the disease occurs.³

What to expect as degenerative myelopathy in my dog progresses

This is the section owners search for at two in the morning, so here it is straight. DM has an invariably fatal outcome once the clinical symptoms begin.⁴

On timing, one study of dogs with the SOD1 mutation found that in the group without a bulging disc, half were still alive at 13 months from the onset of clinical signs, and at 6 months from the time of diagnosis.⁷ That same study found that dogs with the SOD1 mutation appear to have similar disease progression and survival, whether or not they also have a bulging disc.⁷ In the mixed breed case above, the dog continued to get worse over 37 months despite supportive treatment.⁵

Averages are not your dog. They are a planning tool, nothing more.

Is there a treatment for degenerative myelopathy?

A pilot study showed that monthly injections into the fluid around the spinal cord of a drug designed to switch down the canine SOD1 gene were well tolerated in dogs with degenerative myelopathy and reduced SOD1 activity in the spinal cord by more than 50%.⁸ That study described its own field plainly: it shows potential for therapeutic intervention in a fatal disease without a current cure.⁸ DM also matters beyond dogs, because it is an adult-onset disease of nerve breakdown considered a naturally occurring model of human amyotrophic lateral sclerosis, also known as ALS or motor neurone disease.⁹

Anything involving medication, supplements or therapy plans belongs with your vet, who knows your dog's whole picture. What stays in your hands is daily life: footing, rest, bathroom trips, lifting without hurting your own back, and support for walking.

Support for the back legs: the OldPal wheelchair

The OldPal Rear Support Dog Wheelchair is built for dogs with weak or failing back legs. A padded harness carries the weight through the hips and chest rather than the spine, and every strap adjusts. The frame is set so the back legs hang free or lightly brush the ground, and dogs can still squat and go to the bathroom while in the chair. The frame is lightweight aluminum with all-terrain wheels, and each frame adjusts in height within its range.

Sizing is one measurement, not a chart full of them: rear leg height, taken from the top of the hip straight down to the toe pad, with your dog lying on its side and the leg at its natural bend. Five sizes, Mini through XL, cover rear leg heights from 3 to 31 inches.

Next step: measure your dog and check it against the size guide and fit finder. If you would rather have a second pair of eyes, email a photo and your measurement to help@oldpalpets.com and a person will answer. If the size does not fit, our Fit Guarantee means we replace it with the size that does, and return shipping is your only cost. Most orders arrive within 2 to 3 weeks, shipping to the continental US only.

Frequently asked questions

Related guides

• Can degenerative myelopathy in dogs be cured
• Can degenerative myelopathy in dogs be treated

Sources