What is Degenerative Myelopathy?
Where does it come from?
The word degenerative means “progressive deterioration” and the word myelopathy means “disease of the spinal cord”.
Degenerative Myelopathy (DM) is a progressive, non-painful neurodegenerative disease of the spinal cord that mainly affects older dogs. It is often compared to ALS in people.
Some of the more commonly affected breeds include, but are not limited to, Boxers, German Shepherds, Corgis, and others. Dogs usually start showing weakness and ataxia (incoordination) of the hind legs. The neurologic exam is consistent with a T3-L3 myelopathy, meaning we suspect a problem somewhere between the third thoracic and third lumbar spinal cord segments. Patients affected with this disease will eventually become non-ambulatory in the rear, and fecal/urinary incontinent.
Most dogs with Degenerative Myelopathy have a genetic mutation involving the SOD1 gene, and there is a commercially available test for this mutation. This test is usually performed by submitting blood from veterinarian’s office, or by collecting check cells using a swab at the owner’s home. Results are reported as:
- Not Affected/Normal
- Not Affected/Carrier
- Affected/At-Risk
Dogs that are normal or carriers shouldn’t develop the disease, but carriers shouldn’t be breed. Affected/At-Risk dogs may develop the disease, but we don’t know at what age. Since Affected/At-Risk dogs could have another spinal cord problem, MRI +/- CSF tap is still recommended to rule out those other problems.
Commonly Affected Breeds
There are multiple dog breeds which are predisposed to DM including, but not limited to, the following:
- German Shepherd
- Boxers
- Pembroke & Cardigan Welsh Corgis
- Chesapeake Bay Retrievers
- Rhodesian Ridgebacks
- Bernese Mountain Dogs
- Standard & Miniature Poodles
- Terriers (Wire Fox, Kerry Blue, Jack Russell, Mini Schnauzer)
- Golden Retrievers, Pugs, Siberian Huskies, Collies
Although larger dogs are more commonly affected, smaller breeds like corgis often progress more slowly.
Clinical Signs & Symptoms
DM’s progression is gradual—typically unfolding over 9 to 12 months before eventual paralysis and euthanasia. Affected dogs are not in pain, but exhibit signs such as :
- Hind limb weakness, stumbling, difficulty rising
- Rear paw knuckling or dragging; nail wear/abrasions
- Wobbly gait or crossing of hind legs
- Muscle atrophy over time
Because of the slow onset, dogs are often walking with early signs for months before a diagnosis is made.
Diagnosis
Management & Support
Unfortunately, DM cannot be cured at this time. However, there are some things you can do to make a dog more comfortable during the disease process.
- Physical rehabilitation is the owner treatment that has been statistically shown to slow the progression of clinical signs.
- Assistive devices—harnesses, slings, booties, rugs, wheelchairs—reduce injury and help improve mobility.
- Home care—padded bedding, rotating to prevent pressure sores, hygiene management when paralysis leads to incontinence.
There are medicinal treatments marketed for the management of DM, but none have been shown to help.
Need help?
If your dog is showing signs of pelvic limb weakness and/or ataxia, consider scheduling a consultation with your veterinarian or a veterinary neurologist.
For more information or to schedule a consultation, contact Wisconsin Veterinary Neurology & Surgical Center.