Degenerative Myelopathy: Progressive Paralysis in Dogs
Degenerative myelopathy is a heartbreaking progressive spinal cord disease. Understanding the stages helps you plan for your dog's care.
Degenerative myelopathy (DM) is a progressive, non-painful disease of the spinal cord that causes paralysis in dogs. It resembles amyotrophic lateral sclerosis (ALS or Lou Gehrig's disease) in humans. The disease typically affects older dogs and progresses over 6-18 months.
Key Points
- DM is caused by a mutation in the SOD1 gene and is inherited in many breeds
- German Shepherds, Boxers, Corgis, Golden Retrievers, and Bernese Mountain Dogs are at highest risk
- The disease is non-painful but causes progressive weakness and paralysis
- There is no cure; treatment focuses on maintaining quality of life
- Physical therapy and mobility aids significantly improve quality of life
- The final stage requires 24/7 care and euthanasia is often considered
Understanding the Disease
DM affects the white matter of the spinal cord — the pathways that carry signals from the brain to the limbs. The myelin sheath and axons degenerate progressively. The disease starts in the thoracolumbar spinal cord and spreads. It's an autoimmune process triggered by the SOD1 gene mutation. The immune system mistakenly attacks the spinal cord tissue. The disease is non-inflammatory, which is why steroids don't help.
Clinical Stages
Stage 1: Rear limb weakness, knuckling (walking on the top of the feet), and asymmetric gait. One leg may drag. Stage 2: Both rear limbs are weak; the dog may cross the legs when standing or sitting. Falls occur frequently. Stage 3: Rear limb paralysis — the dog cannot stand or walk on the back legs. Urinary and fecal incontinence begins. Stage 4: Front limb weakness develops. The dog may be unable to rise at all. Stage 5: Complete paralysis with difficulty breathing. This stage is rarely reached as euthanasia is typically chosen before this point.
Diagnosis
Diagnosis requires ruling out other causes of rear limb weakness. Your veterinarian performs a neurological exam and tests spinal reflexes. Hip dysplasia, intervertebral disc disease, spinal tumors, and myasthenia gravis must be excluded. MRI of the spinal cord shows characteristic changes. A genetic test for the SOD1 mutation is available — two copies of the mutation confirm susceptibility. CSF analysis rules out inflammatory conditions.
Management & Care
There is no treatment that stops progression. Physical therapy — passive range of motion, swimming, and controlled exercise — maintains muscle mass. Mobility carts (wheelchairs) allow dogs to remain active once paralyzed. Harnesses with handles help support the rear end. Non-slip flooring prevents falls. Regular expression of the bladder prevents infections. The decision for euthanasia is deeply personal — most owners choose when incontinence becomes unmanageable or quality of life declines significantly.
When to See a Vet Immediately
- Your older dog is dragging one or both rear paws
- The rear legs seem weak or wobbly, especially after exercise
- Your dog is knuckling (walking on the top of the feet)
- The weakness is progressing over weeks to months
- There is no pain when you manipulate the legs or spine
How RVC Can Help
This article is for educational purposes only and does not replace professional veterinary advice. If your pet is showing any symptoms, please contact Royal Veterinary Center immediately at +853 6677 6611.