Degenerative Myelopathy

Degenerative myelopathy (DM) is a slowly progressive spinal cord disorder that resembles Amyotrophic Lateral Sclerosis (ALS or Lou Gehrig’s Disease) in people. The inevitable result for dogs with DM is paraplegia- hind end paralysis.

Dogs at risk

DM affects primarily older dogs, with symptoms typically beginning at eight years of age or older. Back in the day (when I was just a pup) we referred to this disease as German Shepherd Myelopathy because we thought it was unique to this breed. We now know that DM occurs in many purebred and mixed breed dogs. The breeds most commonly affected include the German Shepherd, Pembroke Welsh Corgi, Cardigan Welsh Corgi, Boxer, Borzoi, Rhodesian Ridgeback, American Eskimo Dog, Bernese Mountain Dog, Golden Retriever, Great Pyrenees, Kerry Blue Terrier, Poodle, Pug, Shetland Sheepdog, Soft Coated Wheaten Terrier, Wire Fox Terrier, and Chesapeake Bay Retriever.

Symptoms

DM symptoms progress slowly over the course of months to even years. From beginning to end, DM affected dogs typically remain alert and animated. The symptoms usually progress as follows:

  • Initial
    • Loss of coordination (ataxia) in the hind legs.
    • Dragging the hind feet causing wearing down of the toenails.
    • Hind end weakness (difficulty climbing stairs, jumping up into the car, going for walks).
  • Intermediate
    • Knuckling of hind feet (weight bearing on the tops of the feet rather than their undersides).
    • Difficulty supporting weight with hind legs.
    • Inability to walk without support.
    • Urinary and/or fecal incontinence.
  • Advanced
    • Paraplegia (paralysis of hind legs).
    • Weakness in front legs.

Although this degenerative process is not painful, affected dogs can develop discomfort because of overuse of other body parts attempting to compensate for the hind end weakness.

Cause of Degenerative Myelopathy

DM causes degenerative changes within spinal cord axons, structures that transmit information back and forth between the brain and the rest of the body. These degenerative changes begin in the thoracolumbar region of the spinal cord, the portion that lines up with the end of the rib cage. This explains why the hind limbs are more severely affected. Given enough time, the disease progresses towards the head end of the body, causing loss of front leg function as well.

DM is an inherited disease. In 2008 a group of researchers reported that a genetic mutation on the SOD1 gene is a major risk factor for the development of DM. Their study involved Boxers, Pembroke Welsh Corgis, German Shepherds, Chesapeake Bay Retrievers, and Rhodesian Ridgebacks.

The researchers discovered that DM has a recessive mode of inheritance. In order for a dog to be affected, the mutation must be inherited from both dam and sire. What remains unknown is why some dogs who have this “double mutation” never develop symptoms of DM.

Genetic testing for DM

Testing is available to determine an individual dog’s SOD1 mutation status. This test is available through the Orthopedic Foundation for Animals (OFA). All that is required is a blood sample or cheek swab. The current cost for this testing is $65.

This DNA test identifies dogs that are normal (have two normal copies of the gene), those who are carriers (have one normal copy of the gene and one mutated copy), and those who are at risk for development of DM (have two mutated copies of the gene). It is important to remember that DNA testing does not diagnose DM. This is because not all dogs with two mutated copies of the gene go on to develop DM.

Responsible breeders utilize DNA testing for DM to help assess whether or not a particular dog is suitable for breeding purposes. If contemplating purchasing a pup of an at-risk breed, it is important to request DM test results for the dam and sire of the litter of interest. It is also reasonable to have the puppy tested prior to purchase, although, if the parents have been tested and have “normal” results, this is unnecessary.

Making the diagnosis

DM is a “rule out diagnosis”. What this means is that a presumptive diagnosis of DM can only be made by ruling out other causes of spinal cord disease (e.g., herniated intervertebral disk, tumor, infection, trauma). The only way to definitively diagnose DM is via a spinal cord biopsy collected through an autopsy (post-mortem) examination.

The diagnostics performed to rule out other causes of spinal cord disease often include:

  • A thorough physical/neurological examination
  • Blood and urine testing
  • Advanced imaging (CT or MRI scan)
  • Spinal fluid collection and analysis

The cause of spinal cord disease is best diagnosed by a veterinarian who specializes in neurology, internal medicine, or surgery.

Treatment

Currently there is no known treatment capable of significantly altering the course of DM. When searching the Internet, one might find a number of approaches that have been tried or are recommended. Unfortunately, there is no scientific evidence that supports their efficacy.

Prognosis

Unfortunately, the prognosis for dogs with DM is poor. The quality of life for affected dogs can be enhanced through diligent nursing care, prevention of pressure sores, rehabilitation therapies such as swimming and stretching exercises, massage, acupuncture, monitoring for urinary tract infections (immobilized dogs are more prone), and the use of specialized equipment such as booties, slings, harnesses, and wheelchairs to assist with mobility.

DM becomes so debilitating that most people eventually opt for euthanasia. Exactly when to euthanize is a highly individualized decision based on how adaptive, both physically and psychologically, the involved dog and human(s) are. Some dogs thrive in a well-fitted doggie cart/wheelchair. Others are highly resistant to such an apparatus. For the human caretaker, in addition to the emotional toll that DM takes, there is a great deal of lifting, carrying, and cleaning involved. Everyone responds differently to this challenging situation.

Letting go of a beloved four-legged family member is never easy, but it can be particularly heartbreaking when DM is the cause. Affected dogs typically have good appetites, are pain-free, and their minds remain just as sharp as ever. Letting go of a dog who acts or feels sick is usually a bit easier, simply because the process seems to make more sense.

Degenerative Myelopathy and Amyotrophic Lateral Sclerosis

It so happens that, like dogs with DM, some people with ALS carry the SOD1 gene mutation. Having a canine model for studying ALS has important ramifications. Not only might more be learned about the degenerative process that afflicts people with ALS, the canine model may ultimately prove to be valuable in terms of learning more about therapeutic interventions.

Have you ever known or cared for a dog with Degenerative Myelopathy?

Best wishes,

Nancy Kay, DVM

Diplomate, American College of Veterinary Internal Medicine
Author of Speaking for Spot: Be the Advocate Your Dog Needs to Live a Happy, Healthy, Longer Life
Author of Your Dog’s Best Health: A Dozen Reasonable Things to Expect From Your Vet
Recipient, Leo K. Bustad Companion Animal Veterinarian of the Year Award
Recipient, American Animal Hospital Association Animal Welfare and Humane Ethics Award
Recipient, Dog Writers Association of America Award for Best Blog
Recipient, Eukanuba Canine Health Award
Recipient, AKC Club Publication Excellence Award
Become a Fan of Speaking for Spot on Facebook

Please visit http://www.speakingforspot.com to read excerpts from Speaking for Spot and Your Dog’s Best Health.   There you will also find “Advocacy Aids”- helpful health forms you can download and use for your own dog, and a collection of published articles on advocating for your pet’s health. Speaking for Spot and Your Dog’s Best Health are available at www.speakingforspot.com, Amazon.com, local bookstores, and your favorite online book seller.

 

 

 

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19 Comments on “Degenerative Myelopathy

  1. Great article on degenerative myelopathy (DM).

    Thank you for the continuing canine education. There is so much to learn!

    Happy holidays!

  2. Thank you for your article on degenerative myelopathy (DM). I did not know, and am amazed at how much there is to learn about our beloved and loyal canine companions.

    Thank you for the monthly canine education you give all of us.

  3. I have Cardigan Welsh Corgis so of course I am familiar with DM. Fortunately with the genetic marker, most Cardigan breeders are working hard to clear their lines of DM. It is definitely one of the tests being done on a regular basis. With the proper research, it should easy for a puppy buyer to find a “normal” puppy and not have to worry about this sad disease. The National club donates significant funds toward research of this and IVDD. Luckily, Cardigans aren’t wildly popular(yet) like their cousins the Pembrokes. Pembroke breeders will never be able to get a handle on this due to the breed’s popularity in puppy mills.

    Unfortunately, I have firsthand experience with ALS. As a child, I lost my mother to it back in the early 70s. It is a hideous disease leaving it’s victim trapped in a useless body, with no way to communicate as the power of speech is lost. All the while, your brain is healthy and aware. A truly horrid way to die.

  4. Hi Nancy,
    A great overview of a terrible disease–thank you for posting it. I’d like to point out, too, that physical rehabilitation therapy, while not curative, has been shown to be effective in slowing the progress of the disease in a 2009 study by I. Kathmann, et al:

    http://scoutshouse.com/wp-content/uploads/2009/12/RehabTherapyandDM.pdf

    At our rehab therapy center, we’ve treated many dogs with DM over the last ten years and agree with the study’s findings: although our evidence is anecdotal, the dogs we treat consistently and aggressively seem to live longer than the dogs who only come in occasionally or irregularly.

    On our website, we offer a lot of valuable information about DM, including a video on how to care for a dog with DM:

    http://scoutshouse.com/videos/video_degenmyelopathy.html

    and one that shows the progression of the disease in one dog, which we believe can be typical for dogs receiving rehab therapy:

    http://scoutshouse.com/videos/video_progressionDM.html

    And for those who face the hardest choice, we offer a quality of life survey called “When is It Time?” that’s designed to help clarify some of the issues one should consider when thinking about euthanasia for one’s pet. Although that decision is always difficult, for people with dogs with DM it is excruciatingly so. We hope our quality of life survey helps:

    http://www.scoutshouse.com/wp-content/uploads/2009/12/When-Is-It-Time3.pdf

    Thanks again for another thoughtful and informative post, Nancy.

    All the best,
    Lisa Stahr

  5. I own Cardigan Welsh Corgis so of course I am familiar with this disease, fortunately not first hand! I do know that the breed has many wonderful breeders working diligently to breed DM out of their lines. It would be quite easy to find a “normal” puppy. The National club donates significant money for research and we all try to send in DNA samples to increase the database. It is a horrible disease, painless or not. The Pem folks have it much worse since their dogs are so much more popular and many are puppy mill puppies. It will be near impossible to eliminate it in that breed.

    And sadly, I do have first hand experience with ALS. My mother died from it back in the early 70’s when I was a child. Far worse than the lack of mobility is the mental anguish at slowly being trapped in your own body, losing the power of speech, and yet needing help for all aspects of life. The disease is a horror for a human being.

  6. This is one of the best articles I’ve seen on DM. I’ve had 2 DM PWCorgis that have passed, have a 3rd ongoing. This is a great overview hitting many of the top points that are often skipped in other articles, especially the 2nd and 3rd paragraphs under “Prognosis.”

    The one thing I wish more people would be educated about is the period of time before the “Initial” stage when a person with a good eye can tell a dog has DM if they’re aware DM exists in their breed. I was able to tell my DM dogs had DM up to a year before any of the listed “Initial” symptoms were obvious. Unfortunately one can’t really definitively define any symptoms in this pre-initial stage aside from “foot moves just a bit funny.” This is something a person unaware of their dog’s movement won’t see, a vet certainly won’t see it as they don’t know how the dog normally moves, and a person unaware of DM certainly won’t know to even look for it. But if an owner can observe that, they can start the dog in a preemptive PT program to get the dog in fitter shape before muscles start going downhill.

  7. Hi Christa. I’m sorry to hear that you have a dog with DM. I hope Loki’s disease progresses very slowly. I have heard anecdotal stories about amino caproic acid as a treatment for DM. Unfortunately, there is no data that substantiates its efficacy. I encourage you to check in with your veterinarian (who may want to check in with a board certified veterinary neurologist) regarding the pros and cons of twice daily administration versus three times daily. Best wishes to you and Loki.

  8. My German shepherd, Loki, has been suffering the beginning stages of DM all year. A friend who used this drug with his dog long ago had significant success. A delay in the complete paralysis. the drug is called:
    AMINO CAPROIC ACID. Loki is taking 500mg twice daily although he should get it three X according to the pharmacist.
    Do you know about this very helpful compounded pill???
    Thank you for your great article, very helpful and very sad.

  9. Such a timely article, lost my Berner boy on Nov. 26th. I did not have him tested prior to his passing, but his Oncology Vet (survived adenocarcinoma & lived 4 yrs+ & was known as the dog with 9 lives) was pretty certain he had DM. Carlos exhibited all symptoms & was treated with PT & Acupuncture which initially helped. As this horrid disease progressed (he was an extremely active dog) he lost all mobile ability but loved our now servant mode of transport when he hand carried him outside. His decline took almost a year & towards the end he became anxious – aware he could no longer function & protect us. His last weekend was enjoyed but I could tell he was weakening. Our wonderful Hospice Vet came to our home & helped him finish his journey.
    Honestly I had intended to have him DM tested but these last few months have been so overwhelming. Thank you so much for this educational article, I felt better after reading it even tho his absence is still so hard to accept. Time to grieve, he was a very special dog!

  10. I need to tell you and everyone who read your article that this is the BEST summary of DM. Clearly written with the most current facts available. As the owner of a Kuvasz and a Bernese Mountain Dog that had DM, it is a heartbreaking disease. Thank you for covering this disease in your newsletter to help dog owners and potential pet owners looking to acquire a dog breed that has a higher genetic at risk percentage. Being knowledgeable and asking breeders to do testing will push more breeders to do this simple test before they breed. For dog owners living with dogs with DM or suspected DM there is at least two DM Yahoo groups for help and support.

  11. I had a Golden Retriever who was believed to have had DM. At the time, there were no documented cases of DM in Goldens. He had all the symptoms. He lived to be 14.5 years old. We had a custom Eddie’s Wheels wheeled cart but he would not use it. I toweled him for pottying. He also had Canine Cognitive Disorder (CCD). His days and nights were mixed up. The foot dragging got better for a few months while on L-Deprenyl (compounded into a meat treat.) We used infant socks wrapped with vet wrap to keep the top of his toes from bleeding. He was a happy guy for around seven months, eating well, drinking, enjoying car rides, visiting with neighbors and friends. Then one day he had one seizure, lost control of his bowels and bladder, and looked at me, like, “Make it stop,” and we let him go the next day.

  12. Thank you for publishing this article. Our Pembroke Welsh Corgi, Georgie, had DM. She had three good years after her diagnosis before her death. She had a wheeled cart which allowed her to get around for most of those years. When she became too tired on a walk, we would put her in a stroller and set the cart on top.

    There are a number of resources available for owners of Corgis with DM. CorgiAid sponsors a cart loan program (http://corgiaid.org/cart/index.php). They also offer a book about caring for your wheeled Corgi by Bobbie Mayer (http://corgiaid.org/cart/corgisonwheels/).

    Facebook has groups for all breeds with DM (https://www.facebook.com/groups/DMDogs/) and a specific group for Corgis (https://www.facebook.com/groups/57598352536/).

    In addition, Bobbie Mayer coordinates an email list for owners of WheelCorgis (https://groups.yahoo.com/neo/groups/wheelcorgis/info).

    I know that there are other breed specific resources, but I’m not familiar with them. I hope others will chime in with their knowledge.

  13. Thank you for a very accurate and up-to-date article on DM. I moderate a Yahoo group, Corgis on Wheels, and a majority of the members have or have had a corgi with DM. Even now some of them struggle to get a diagnosis (and with corgis the signs of type II IVDD can look identical to DM). I had a corgi with DM, Merlin, who died four years ago, and it is a heartbreaking disease.

  14. My sister and her family just had to accompany their Golden boy, Denver, to the bridge almost two months ago. He was the poster boy for Golden Retrievers and it was heartbreaking for them to see him lose his mobility and become incontinent. He lived to chase his ball and they felt that he was not truly “living” his happy doggie life anymore. As you mentioned he still had a good appetite was a happy boy and healthy in all other ways till the end. A very difficult decision for them. This DM is a very cruel illness indeed. Goodbye sweet Denver. You were so loved and deeply missed by everyone who knew you.

  15. My 12 year old Tibetan Terrier suffered from DM. We tried physical therapy and she used a cart until the illness final worked into her front legs. Her vocal cords were also affected. It was heartbreaking to see her body wasting away and yet her mind was functioning. She struggled to move. Finally, we knew that she was suffering, not pain of the body, but in her mind. She couldn’t move herself and struggled. We loved her enough to let her go. She had two litter mates that had CCL and I always wondered about a link between both diseases!

  16. Thank you! I have a 7 year old standard poodle, a rescue from the Dallas Poodle shelter. he was the runt of a litter from breeding two very young standard poodles, the 7 puppies were all sick and all 9 dogs were surrendered as the wonders could not pay for veterinary care. I got Choco at 9 months, he has multiple allergies and skin problems. My local veterinarian (actually 2), did not respond to my report that Choco can no longer jump up I to our truck ( we raise horses and take him on trips with us trail riding), and he is falling down with his back legs slipping out from under him. Sadly this explains what is probably the reason. he’s had a wonderful life on the farm. I will help him as long as I can, we lift him into the truck now and to get on to the bed with us at night. Thank you for your post.

  17. Hi Linda. I’ve not yet blogged about immune mediated hemolytic anemia (IMHA), but hope to do so before too long. Thanks for your suggestion.

  18. Do you have any blogs/write ups on IMHA? My foster Pekingese, Lexie, has this and I’m trying to learn all I can about it. She is 11 pounds and so sweet. Has been on treatment for 4 months now.

  19. I had two pugs back to back with DM. Our first DM pug, Kayla, fought the disease for nearly 20 months from her initial symptoms. We bought her a wheelchair, which she fully resisted. She was far too independent to have help of any sort, including the wheels. By the time we made the difficult decision to say goodbye to Kayla, she had started knuckling her front feet, indicating that the DM was beginning to affect her front end. But her mind was there until the very end. She was a bright, alert, sharp, happy girl until we made the decision to let her go, about a week before we said goodbye. At that point, she had stopped enjoying things she was enjoyed and we felt her quality of life was declining. We said goodbye to Kayla on February 12, 2011.

    Our second DM pug, Gracie Lou Freebush, fought DM for 32 months. This girl was a fighter like I’ve never seen before. When she lost use of her backend, she simply dragged herself wherever she needed to go. She was determined to carry on despite her limitations. And she was one happy little girl. Grace was a former puppy mill breeder, so she had already had a rough start to life. But I think her beginning had a lot to do with how long she fought DM – she just didn’t know how to quit! We didn’t get a wheelchair for Grace, after our experience with Kayla rejecting hers. Besides, at just 16 pounds, Grace was easy enough to pick up and carry around when we needed to move her. We said goodbye to Grace on July 1, 2013, just a little two years after we lost Kayla.

    Caring for a DM dog is hard and lonely and isolating. It’s difficult for others in your life to understand that your DM dog is not suffering. It’s hard to hear others say, “Poor dog” when you know in your heart that he/she isn’t suffering and has a wonderful quality of life, just with limitations. The greatest gift I received from both of my DM dogs was to learn to live in the moment. Because I knew our time together was limited, I was forced to enjoy our time together, however long or short that may be. What an amazing way to live! I was able to enjoy every day more than I’d have otherwise enjoyed it. Even when I was cleaning up potty on the floor for the 5th time that day, or giving one of the girls a second bath of the day because she fell in her potty or poop, or shampooing my carpets, or picking up a trail of turds that she dropped along the floor. It’s so easy to get frustrated by these moments, but much better to simply be thankful that you still have your dog with you to create these messes. Because when they’re gone, you’ll find yourself thinking you’d give anything to have to clean up messes because at least you’d have your baby back.