Canine Degenerative Myelopathy: Causes, Symptoms & Care

Canine degenerative myelopathy (DM) is a progressive, incurable neurological disease affecting the spinal cord in older dogs, similar to human amyotrophic lateral sclerosis (ALS). It typically manifests in dogs over seven years of age and leads to gradual weakness, loss of coordination, and eventual paralysis in the hind limbs.

Dog Breeds Most At Risk of Degenerative Myelopathy

The condition is hereditary and strongly linked to a mutation in the SOD1 gene. While over 43 breeds have been identified at risk, some breeds stand out due to a higher prevalence. These include the German Shepherd, Boxer, and Pembroke Welsh Corgi. Other breeds affected include the Cardigan Welsh Corgi, Wire Fox Terrier, and Rhodesian Ridgeback.

Understanding Genetic Testing and Its Importance

Genetic testing for the mutated gene involved in DM is an essential tool for responsible breeders and owners. Testing results fall into three categories:

• Normal (clear): The dog does not carry the mutated gene and is not at risk of passing it on.
• Carrier (normal/abnormal): The dog carries one copy of the mutated gene; it is unlikely to develop the disease but can pass the mutation to offspring.
• Affected (abnormal): The dog has two copies of the mutation, likely to develop DM and pass it on.

Breeding Considerations and Inherited Risks

When planning breeding, understanding genetic risks helps reduce the chance of affected puppies:

• If both parents are clear, puppies will not inherit DM.
• If one parent is a carrier and the other clear, about half the puppies may be carriers but unlikely to be affected.
• If both parents are carriers, approximately 25% of puppies may be affected, 50% carriers, and 25% clear.
• If one parent is affected and the other clear, all puppies will be carriers.
• If one parent is affected and the other a carrier, around half the puppies may be affected and half carriers.
• If both parents are affected, all puppies will be affected by DM.

Recognising Symptoms and Disease Progression

Symptoms typically begin with hind limb weakness and loss of coordination, often mistaken for arthritis at first. Dogs may drag their rear paws or scuff their toenails. Over time, symptoms worsen with paralysis of the hind legs, balance issues, incontinence, and eventually front limb involvement. The disease progression is variable but can span months to several years.

Supportive Care and Managing Quality of Life

Currently, there is no cure for DM. Treatment focuses on maintaining comfort and mobility for as long as possible. This can include:

• Physiotherapy and massage to preserve muscle tone.
• Hydrotherapy, which assists mobility without overexertion.
• Use of ramps instead of stairs to ease movement.
• Rear-leg slings or wheeled carts to help dogs exercise and stay mobile when paralysis starts.
• Regular, manageable exercise tailored to the dog's ability.

Providing supportive care with compassion can significantly improve quality of life and prolong comfortable mobility.

Early Recognition and Responsible Ownership

Early recognition of symptoms and genetic testing within at-risk breeds allow owners and breeders to make informed decisions, promoting responsible breeding practices to reduce the incidence of this debilitating disease. If you are considering acquiring a dog from a breed prone to DM, seek reputable breeders who perform genetic screening to help support the health and welfare of future generations.

Consult your vet promptly if your dog shows early signs of degenerative myelopathy or any changes in mobility for a thorough assessment.