Early Signs of Degenerative Myelopathy in Dogs
Degenerative myelopathy (DM) is a progressive and ultimately fatal neurological disease that affects the spinal cord in dogs. Often compared to amyotrophic lateral sclerosis (ALS) in humans, DM primarily targets middle-aged to senior canines and results in muscle weakness and loss of coordination, starting in the hind limbs. Understanding the initial symptoms of this devastating condition can aid early detection and prolong the dog's quality of life.
What Is Degenerative Myelopathy?
Degenerative myelopathy is a chronic, non-painful neurodegenerative condition of the spinal cord. It typically develops between the ages of 4 and 14 and has a genetic association with a mutation in the
SOD1 gene. Over 40 dog breeds are known to be genetically predisposed, including:
- German Shepherds
- Pembroke and Cardigan Welsh Corgis
- Boxers
- Chesapeake Bay Retrievers
- Golden Retrievers
- Siberian Huskies
- Standard and Miniature Poodles
- Pugs
- Collies
- Soft-Coated Wheaten Terriers
The disease causes progressive white matter degeneration in the spinal cord, resulting in muscle atrophy, motor dysfunction, and eventual paralysis.
First Symptoms to Watch For
The initial symptoms of degenerative myelopathy are often subtle and may resemble normal aging or other musculoskeletal issues. Key early signs include:
- Hind limb weakness—dogs may have difficulty rising or appear to “wobble” when walking.
- Loss of coordination (ataxia)—unsteady gait or stumbling, particularly in one hind limb.
- Knuckling of the paws—the dog may drag its toes or walk on the top of its feet.
- Swaying of the hindquarters—unstable or shaky rear end when standing or walking.
- Scraping of nails—visible wear from dragging the feet during movement.
These symptoms often progress slowly but relentlessly. As both hind limbs become affected, mobility deteriorates further.
Progression of Symptoms
As DM advances, the affected dog will exhibit:
- Muscle loss in the rear limbs due to disuse
- Crossing of rear legs and difficulty maintaining balance
- Increasing difficulty rising or climbing stairs
- Dragging of hind limbs and reliance on front legs
- Loss of urinary and bowel control
- Eventually, forelimb involvement and respiratory decline
Most dogs become paraplegic within six to twelve months after diagnosis if no supportive care is given.
How Is DM Diagnosed?
Degenerative myelopathy is a diagnosis of exclusion, meaning veterinarians must first rule out other conditions:
- Herniated discs
- Spinal cord tumors
- Arthritis
- Infections or trauma
Testing may include:
- Spinal radiographs (x-rays)
- MRI or CT scans
- Myelography
- Cerebrospinal fluid analysis
- Genetic testing for the SOD1 mutation
A definitive diagnosis can only be made through post-mortem histopathological examination of spinal tissue.
Treatment and Management Options
There is currently no cure or definitive treatment for DM. Management focuses on maintaining quality of life and slowing disease progression:
- Physical therapy and hydrotherapy (e.g., swimming) to preserve muscle tone
- Mobility aids like harnesses, slings, and dog wheelchairs
- Supportive nursing care for hygiene, pressure sores, and urinary tract infections
- Weight control to reduce strain on limbs
- Environmental modifications such as ramps and padded flooring
Though ongoing studies are exploring therapeutic compounds, no medication has yet shown consistent benefit.
Genetic Considerations
DNA screening for the SOD1 mutation can identify:
- Clear dogs (no mutation)
- Carriers with one copy of the mutation
- At-risk dogs with two copies
Breeding programs should avoid mating carriers or at-risk dogs to minimize disease spread.
Prognosis
Due to the steady progression and lack of a cure, the prognosis is poor. Most dogs succumb to the disease or are euthanized within 12–24 months after symptom onset. Nonetheless, with proper care, some dogs live longer and maintain a decent quality of life.
Conclusion
Degenerative myelopathy is a heartbreaking yet non-painful condition that affects a dog's nervous system and steals away mobility. Recognizing the
first symptoms—such as subtle hind limb weakness, coordination issues, or paw dragging—can lead to early diagnosis and allow pet parents to implement supportive interventions. While there is no cure, compassionate care and diligent monitoring can significantly enhance the well-being of affected dogs.
