A Dog Lover‘s Guide to Degenerative Myelopathy: Holding Onto Hope Through the Heartbreak

As a dog lover and veterinarian, few things break my heart quite like a diagnosis of degenerative myelopathy (DM). This progressive, incurable disease of the spinal cord robs once active, playful dogs of their ability to walk, play, and even control their bladder and bowels. It‘s a disease that tests the strength of the human-animal bond and challenges us to find ways to make every remaining day a good one.

I‘ve held the hands of numerous devoted owners as they grappled with the reality of a DM diagnosis. I‘ve cried with them, celebrated the good days, and ultimately helped them make the difficult decision to say goodbye when their beloved companion‘s quality of life was no more. Through it all, I‘ve been in awe of the resilience of these incredible dogs and their dedicated humans.

If you are facing a DM diagnosis, know that you are not alone. By better understanding this challenging disease, you can more fully support your dog through the journey ahead. As a veterinarian and dog lover, I‘m here to help you navigate degenerative myelopathy with knowledge, compassion, and a focus on savoring every moment with your sweet pup.

Understanding Degenerative Myelopathy

Degenerative myelopathy is a progressive disease of the spinal cord that leads to slowly worsening hind limb weakness and paralysis. It affects the white matter tissue, which contains nerve fibers that transmit movement signals from the brain to the limbs. Over time, DM causes degeneration of this white matter, disrupting the communication between the brain and hind legs.

The exact cause of DM is still not fully understood, but we know there is a strong genetic component. A mutation in the SOD1 gene, which codes for an important antioxidant protein, is a major risk factor for developing DM. This mutation is common in several breeds, especially German Shepherds, Boxers, Chesapeake Bay Retrievers, and Pembroke Welsh Corgis. However, not all dogs with the SOD1 mutation will develop clinical signs of DM.

Breed	Prevalence of SOD1 mutation	Lifetime risk of DM
German Shepherd	37%	20%
Boxer	39%	10%
Chesapeake Bay Retriever	39%	11%
Pembroke Welsh Corgi	68%	8%

Data from: Zeng R, Coates JR, Johnson GC, et al. Breed distribution of SOD1 alleles previously associated with canine degenerative myelopathy. J Vet Intern Med. 2014;28(2):515-521. doi:10.1111/jvim.12317

The SOD1 mutation is thought to cause an accumulation of free radicals that damage the nerve fibers in the spinal cord. However, not all dogs with two copies of the mutation develop DM, suggesting that other genetic and environmental factors likely play a role. Some researchers have proposed that intense exercise, such as that experienced by working dogs, could be an environmental trigger. However, more research is needed to fully understand the complex interplay of genes and environment in the development of DM.

Signs of Degenerative Myelopathy in Dogs

Degenerative myelopathy typically has a slow, insidious onset, with symptoms gradually worsening over the course of 6 months to 3 years. Most dogs are at least 8 years old at the time of diagnosis, although some may show signs as early as 4-5 years old. The progression of DM is often divided into three stages:

Early stage:

• Subtle hind limb weakness and loss of coordination
• Scuffing or dragging back paws
• Wearing of toenails
• Knuckling over and walking on tops of feet
• Swaying or staggering in hind end
• Difficulty rising, climbing stairs, or jumping

Mid stage:

• Worsening hind limb weakness and ataxia (uncoordinated movement)
• Crossing hind legs when walking
• Frequently stumbling and falling
• Significant muscle atrophy (wasting) in hind legs
• Limp, unresponsive tail
• Urinary and fecal incontinence

Late stage:

• Complete paralysis of hind legs
• Inability to walk or stand, even with support
• Front limb weakness in some cases
• Severe urinary and fecal incontinence
• Difficulty repositioning when lying down
• Potential for pressure sores and urine scald

Progression through these stages varies significantly between individual dogs. Most dogs with DM become paraplegic (unable to use their hind legs) within 6-12 months after the onset of signs. However, some may retain the ability to walk for 18-24 months or more with supportive care. Rarely, DM can progress to affect the front limbs in the late stages, although most dogs are euthanized due to quality of life concerns before reaching this stage.

It‘s important to note that DM itself does not appear to be a painful condition. However, the loss of mobility and inability to fully reposition can lead to discomfort. Pressure sores, urine scald, and even orthopedic pain from altered compensatory movement can all impact a dog‘s comfort and quality of life as the disease progresses.

Diagnosing Degenerative Myelopathy

Degenerative myelopathy is notorious for being difficult to definitively diagnose. No single test can confirm DM in a living dog. Instead, veterinarians must rely on a combination of clinical signs, diagnostic test results, and ruling out other conditions that can mimic DM.

If your vet suspects your dog may have DM, they will start with a thorough neurological exam to assess hindlimb reflexes, strength, and coordination. Affected dogs often have exaggerated hindlimb reflexes, even as their voluntary movement deteriorates. Proprioception, or the ability to sense the position and movement of the limbs, is often severely reduced in the hind legs.

Advanced imaging, such as magnetic resonance imaging (MRI), can be helpful to rule out other conditions that can cause similar symptoms. Intervertebral disc disease (IVDD), spinal tumors, and vertebral instability can all cause hind limb weakness and ataxia. While an MRI cannot diagnose DM, it can help rule out these other differentials.

Genetic testing for the SOD1 mutation can lend further support for a presumptive diagnosis of DM, particularly for an at-risk breed with characteristic clinical signs and imaging findings. However, a positive SOD1 test alone is not diagnostic for DM, as some dogs with the mutation never develop clinical disease. Similarly, a negative test does not completely rule out DM, as some affected dogs are negative for the SOD1 mutation.

Some veterinarians may recommend conducting a cerebrospinal fluid (CSF) tap to collect a sample of the fluid surrounding the brain and spinal cord. While there are no specific CSF changes diagnostic for DM, this test can help rule out inflammatory conditions.

Ultimately, a definitive diagnosis of degenerative myelopathy can only be made post-mortem by microscopic examination of the spinal cord tissue on necropsy. The characteristic histologic lesion is a loss of axons and myelin (nerve fiber insulation) in the white matter of the thoracic spinal cord. For many pet owners, a presumptive diagnosis based on clinical signs, SOD1 status, and ruling out other conditions is sufficient. However, some may choose to pursue a necropsy after euthanasia for closure and to advance our understanding of this challenging disease.

Living with a Dog with Degenerative Myelopathy

Learning to adapt and support your dog as DM progresses is an act of love, devotion, and incredible resilience. As your dog‘s mobility declines, it‘s important to work closely with your veterinarian to develop a plan for maintaining quality of life.

Supporting Mobility and Comfort

Physical rehabilitation is a cornerstone of DM management. This often includes:

• Passive range of motion exercises
• Massage to promote circulation and prevent stiffness
• Hydrotherapy in an underwater treadmill
• Assistive devices like slings, harnesses, and wheelchairs or carts

A veterinary rehabilitation specialist can tailor a program to your dog‘s specific needs and teach you techniques to continue at home.

As the disease progresses, your dog may need additional support to move around. Booties or toe grips can help with traction on slippery floors. Placing runners and area rugs along frequently traveled paths can also help with stability. When your dog can no longer walk unassisted, slings or rear-end harnesses can allow you to support their hind end on walks or trips outside to eliminate.

For dogs in the mid to late stages of DM, a custom-fitted cart or wheelchair allows them to continue enjoying walks and playtime once their hind limbs are too weak to support them. While these can be expensive (often $300-$600), many dogs quickly adapt to the increased mobility they provide.

Nursing Care

As DM progresses, your role often shifts from being your dog‘s playmate and walking companion to being their nurse and caretaker. Affected dogs often need:

• A soft, supportive bed to prevent pressure sores
• More frequent trips outside to urinate and defecate
• Help repositioning when lying down
• Diapering or expressing the bladder if urinary incontinence develops
• Gentle bathing if they experience urinary or fecal accidents
• Feeding in an upright position to avoid choking or regurgitation
• Moistening dry food or switching to a soft food for ease of chewing and swallowing

While these new responsibilities can feel overwhelming at times, know that your devoted care makes an enormous difference in your dog‘s quality of life.

Maintaining Mental Stimulation

One of the most heartbreaking aspects of DM is watching a once active dog slowly lose their ability to run, play, and even walk. However, there are still many ways to enrich your dog‘s life and keep that sparkle in their eyes.

Mental stimulation becomes increasingly important as physical activity becomes more difficult. Puzzle feeders, scent work games, and even trick training are all great ways to engage your dog‘s mind and keep them feeling valued and fulfilled.

Even as their mobility declines, sensory experiences like trips to the dog park to see friends or rides in the car to take in the sights and smells of their favorite places provide enrichment. Reading to your dog or just sitting quietly together in nature allows them to bask in your companionship.

Maintaining social connections is also important for dogs with limited mobility. Invite gentle, well-mannered dog friends over for visits. If your dog is very social, look into dog-friendly service organizations that may welcome well-behaved dogs in carts or strollers to come spread some cheer. The mental stimulation and mood boost of gentle social interactions can be powerful.

Deciding When to Say Goodbye

Making the decision to euthanize a beloved dog is never easy, but it is an all too common reality with degenerative myelopathy. Euthanasia is typically recommended when a dog reaches the point where they can no longer walk or stand on their own, even with sling support.

Some owners elect euthanasia sooner, particularly if incontinence or pressure sores develop. Others choose to continue supporting their dog with intensive nursing care, as long as they perceive their dog still has good quality of life and seems happy overall.

There is no single "right" time to say goodbye to a dog with DM. It is an intensely personal decision that depends on your dog‘s specific situation and your family‘s ability to care for them. Factors to consider include:

• Can your dog move around enough to prevent pressure sores?
• Are they continent, and if not, can you manage their bladder and bowels?
• Are they still eager to eat and engage with you and their surroundings?
• Do they seem generally content and peaceful most of the time?

While the thought of life without your beloved companion is almost too much to bear, euthanasia is often the final act of love we can provide for dogs with advanced DM. It is never an easy decision, but it is a privileged one. We can prevent suffering and ensure our faithful friends know only love and comfort in their final moments.

If you are considering euthanasia for your dog with DM, talk openly with your veterinarian. They can help you evaluate your dog‘s quality of life and will support you in making the best decision for your dog and your family.

Finding Support

One of the most important pieces of advice I give owners caring for a dog with DM is to cultivate a support system. Friends, family, your veterinary team, and even an online community can all provide much-needed emotional support, advice, and practical help along the way.

Consider connecting with other owners of dogs with DM through social media groups. Nobody else will quite understand the joys and challenges of life with a dog with this condition. Celebrate the victories together, trouble-shoot problems, share recommendations for helpful products, and know you have a safe place to share the more difficult moments.

Establishing a strong relationship with your veterinarian is also important. They can provide invaluable medical guidance and emotional support throughout your dog‘s DM journey. Don‘t hesitate to reach out with questions or concerns along the way.

Finally, be honest with friends and family about how they can best support you. Maybe it‘s coming over to sit with your dog while you run errands, preparing a meal, or just providing a listening ear after a difficult day. Accepting help is not a sign of weakness; it‘s an acknowledgement of just how much mental and physical energy it takes to care for a dog with a chronic, progressive disease.

Holding onto Hope

While it can be difficult to remain hopeful in the face of a degenerative myelopathy diagnosis, I encourage you to hold onto optimism whenever possible. Celebrate the small victories and good days. Cherish the quiet moments of connection with your sweet dog. Find joy in their resilience and ability to adapt to new challenges.

It‘s also important to hold onto hope for a better future for dogs with DM. Researchers are studying several promising therapies that may one day improve the outlook for affected dogs:

• Gene therapy: Scientists are investigating gene therapy techniques to reduce the accumulation of toxic SOD1 proteins in the neurons of dogs with DM. While still in early stages, this approach could one day slow or even stop the progression of DM.

• Stem cell therapy: Researchers are exploring the use of stem cells to regenerate damaged nerve fibers and support remaining healthy neurons. Results in DM-affected dogs have been mixed so far, but this remains an active area of study.

• Neuroprotective drugs: Several medications that protect neurons from damage are being evaluated for use in dogs with DM. While these are unlikely to reverse existing damage, they could potentially slow disease progression, especially if started early.

While these potential therapies are all likely years away from routine clinical use, it‘s encouraging to know that researchers continue to study DM. With dedicated scientists, veterinarians, owners, and dogs working together, I‘m hopeful that we will one day have better treatments or even a cure for this devastating disease.

Final Thoughts

My heart goes out to you and your dog if you are facing a diagnosis of degenerative myelopathy. This disease is challenging, heartbreaking, and at times, downright exhausting. But even in the face of such difficulties, you and your dog can and will experience moments of incredible joy, connection, and unwavering devotion.

The human-animal bond is never stronger or more apparent than when navigating a chronic, progressive illness together. Your dog will teach you about patience, adaptability, resilience, and unconditional love. You will stretch and grow in ways you never thought possible as you rise to meet their evolving needs. Through it all, you will know that you are giving them the greatest gift – the security of your love and presence every step of the way.

I hope that you have found this guide informative and comforting as you navigate your dog‘s DM journey. Know that you don‘t have to walk this path alone. Lean on your veterinarian, your support system, and your unbreakable bond with your beloved dog. Celebrate the good days and be kind to yourself on the difficult ones. Most of all, cherish every moment, every snuggle, every tail wag, and every precious day you have together.