Degenerative myelopathy is a disease of the spinal cord. It affects older dogs and is similar to ALS (Lou Gehrig’s Disease) in humans.
In dogs, it starts as a limp or a wobble in the hind before progressing to eventual paralysis. The paralysis is caused by the gradual deterioration of white matter from the spinal cord.
White matter consists of the fatty substance that surrounds nerve fibers.
You could call it the “wiring” of the nervous system. Naturally, if that breaks down, the communication signals from the brain become broken.
How Do I Know if My Dog Has Degenerative Myelopathy?
In the very early stages, the signs of degenerative myelopathy in dogs may look like osteoarthritis. It’s not unusual for aging dogs to feel stiffness when getting up after a nap. Senior dogs, like humans, begin to feel mild to moderate aches and pains as part of everyday life.
As the disease progresses, dogs with degenerative myelopathy will show signs of loss of coordination and may appear wobbly on their feet. Onset typically occurs in dogs over 8 years of age.
One of the most difficult aspects of this disease is getting a diagnosis. To date, there is no specific test that will point to DM. Instead, veterinarians must go through a checklist of potential causes to rule out everything else.
Degenerative Myelopathy typically paralyzes a dog within six months to a year after onset of disease.GVR, GA Veterinary Rehab, Fitness & Pain Management
What Other Conditions Cause Weakness, Limping, and Difficulty Standing?
Degenerative myelopathy is a disease that affects the spinal cord. However, there are other conditions that may have similar signs including:
- Herniated intervertebral disks
On assessment, a veterinarian will be able to rule out many of the above conditions based on your dog’s prior medical history.
Blood tests, urinalysis, CT scans, etc. are not able to diagnose DM. However, a veterinarian can use these tests to rule out other possible causes.
What Breeds are Prone to Degenerative Myelopathy
As mentioned earlier, the dogs that develop this condition are usually middle-aged to senior. A dog is considered “senior” when he/she reaches the age of 7.
Although the disease can make an appearance in any dog breed, the predominant breeds include:
- German Shepherd (predominant)
- Chesapeake Bay Retrievers
- Rhodesian Ridgebacks
- Standard Poodles
The disease can occur in male and female dogs.
Is Degenerative Myelopathy Painful for Dogs?
Thankfully, there is no pain associated with the condition.
What Does the Disease Do to the Dog’s Body?
The disease is caused by a mutation in the superoxide dismutase (SOD1) gene.
Certain dog breeds (noted above) develop the mutation after inheriting two mutated genes (one from each parent). This is known as a autosomal recessive pattern.
The mutation of the SOD1 gene directly affects axons (long nerve fibers that move electrical impulses) and myelin (the insulating cover that surrounds the nerve fibers).
In a normal, healthy body, the brain sends electrical impulses that communicate with nerve fibers throughout the body. The brain tells the nerve cells in the spinal cord what to do.
That message causes the nerves in the spinal cord to jump to action. In turn, the spinal cord sends the message out through the axons.
When those axons (long nerve fibers in the spinal cord) and the myelin are damaged (as they are with deteriorating myelopathy), the body loses its ability to function normally.
Can My Dog Be Treated for Degenerative Myelopathy?
Unfortunately, this disease is fast-moving and there is no quantifiable evidence that medical treatment halts or slows the progression.
The best a dog owner can do is treat the symptoms with the dog’s quality of life in mind.
Treating the symptoms as they progress can help maintain a good quality of life in a dog that has been diagnosed with this terrible disease.
Physical therapy, special hind end harnesses to aid a dog in walking, preventing foot damage, and increasing traction by walking a dog on grass instead of concrete and placing rugs on slippery floors may help delay the need for euthanasia.
Supportive Therapy for Dogs with Degenerative Myelopathy
There may not be much you can do for your dog medically, but there are some things you can do to help your dog experience all of the things he/she still loves. For example, an assistive sling will help your dog get outside for potty breaks.
Slings are useful tools for short walks as well.
As you dog slowly loses the ability to do the things he/she used to do (jump, for example), consider purchasing a supportive and comfortable dog bed that’s lower to the ground.
Depending on the size of your dog, carriages are a wonderful way to get your dog outdoors. Remember, your dog’s sense of smell and vision will remain acute for a while so getting them outside offers them familiar joy.
It’s thought that physical therapy may help delay the muscle atrophy/weakness associated with degenerative myelopathy.
Regular walking (assuming the dog is still able to walk) may help maintain mobility for longer.
Strengthening & Conditioning Exercises
Exercises such as swimming and climbing stairs are two examples of strengthening exercises for dogs. It’s important to have a physiotherapist who specializes in canine recovery monitor any activities undertaken.
Exercise should be monitored and carefully planned depending on the dog’s abilities. Too much exercise can cause pain and injury.
Proper execution of conditioning exercises may help to maintain strength, balance, and mobility for a little longer.
There is some thought to supporting dogs with degenerative myelopathy with a combination of mild exercise and nutritional supplements.
Although there are many types of nutritional supplements on the market, it’s unlikely they were formulated for the unique needs of a DM patient. The best advice for nutritional supplementation will come from your veterinarian.
Will a DNA Test Tell Me If My Dog Carries the Mutated Gene?
There are several canine DNA tests on the market, but the results may not be 100% accurate and shouldn’t be used as a diagnostic tool.
You can, however, discuss gene-testing with your veterinarian. In addition, you can obtain a legitimate DNA testing kit at the Orthopedic Foundation for Animals (OFFA).
The cost of the test is approximately $65 dollars and includes an explanation of the results.
You’ll go through a series of questions about your dog and what/how-much information you agree to release to the public.
In order to benefit others in their research, the application process also asks if you would be willing to donate blood/tissue samples. There is also an opportunity to agree to free clinical trials for dogs with degenerative myelopathy.
Further Reading: Life Expectancy of a Dog with Dilated Cardiomyopathy
9 Signs of DM Progression in Dogs
Unfortunately, DM in dogs is a progressive disease eventually leading to paralysis.
The disease doesn’t always progress at the same rate; however, signs can be categorized as being in the early, middle, or late stage.
The disease is not considered painful for the dog and dogs tend to remain alert with intact personality traits as the disease advances.
Starting from the early stages and ending with the final stages, signs include:
#1. Loss of coordination in the hind legs.
#2. Dragging the feet (back legs)
#3. Difficulty jumping into the car, onto the sofa, etc.
#4. Knuckling of feet. When this happens, the dog walks on the tops of the feet instead of the bottom.
#5. Unable to support the weight of the hind legs without help.
#6. Unable to walk without support.
#8. Paralysis of the hind legs
#9. Front leg weakness.
At the end of the day…
Degenerative myelopathy is a slow progressing disease that breaks down communication to the spinal cord.
Dogs with this disease typically live anywhere from 1 – 3 years. However, the majority of dogs are euthanized within the first year before quality of life severely deteriorates.
If you are dealing with this disease and need help coping with the loss, please read this article by HelpGuide.org.:
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Merck Manual – Veterinary Manual
GVR – GA Veterinary Rehab, Fitness, and Pain Management
VCA Hospital Tufts University