Thursday, February 28, 2013

Degenerative Myelopathy in Dogs, by Dr. Dana Lewis

Degenerative Myelopathy (DM) is a slowly progressive disease that affects the spinal cord and a dog's ability to walk. DM results in lost coordination of the hind legs, which progresses to weakness and then to paralysis of the hindquarters. It may cause problems with elimination. It will ascend to the front limbs and also interfere with breathing eventually. Once the dog reaches the point where he can no longer walk, pressure sores, urine leaking and scalding, and loss of bowel control are likely to develop if the patient is not attended to.

The nerves in the mid to lower spinal cord are affected first, and the myelin sheaths that protect the nerves degenerate in this disease. The cause is a DNA mutation in a gene called superoxide dismutase 1 (SOD1). The neurologic disease is similar to some forms of human amyotrophic lateral sclerosis (ALS, often called Lou Gehrig's disease). The DNA test does not determine if a pet is suffering from DM but if he is at risk of developing signs. The test identifies dogs that are clear and have two normal copies of the gene, carriers who have one normal copy and one mutated copy, and those who are at much higher risk for developing DM because they have two mutated copies. But just because a dog has two mutated copies of the gene, it does not mean he will definitely develop the disease. Unfortunately, the only way to confirm the diagnosis is after the pet passes by examination of the spinal cord.

It affects older large breed dogs, particularly German Shepherds, but also Bernese Mountain Dogs, American Water Spaniel, Bloodhound, Borzoi, Canaan Dog, Chesapeake Bay Retriever, English Cocker Spaniel, Great Pyrenees, Kerry Blue Terrier, Sealyham Terrier, Whippet, Collies, Mastiffs, Setters, Old English Sheep Dogs, Huskies, Ridgebacks, and the only small dog that is more commonly affected is the Pembroke Welsh Corgi.

Dogs who are mixes of any of these breeds are also at risk. Other dog breeds can get it, but it’s less likely. Most small dogs and cats rarely are affected.

Typically, degenerative myelopathy isn't seen in dogs under the age of five, and more often it is between 8 and 14 years that it occurs. Because the disease is found in specific breeds, responsible breeding is the only way to prevent degenerative myelopathy. If you plan to get a purebred puppy of an affected breed, ask the breeder about history of DM in the kennel’s line. Understand that clinical signs don't develop until long after sexual maturity.


Often the first signs noticed are difficulty in the hind quarters when the dog is getting up particularly on a smooth surface. As the disease progresses, the dog becomes uncoordinated, will sway, the limbs may criss-cross each other and will scuff or drag the rear feet, knuckle over and not be aware of it, causing excessive wearing of the toenails. The muscles waste away and become weaker.

Sometimes one side is more uncoordinated than the other. The disease can wax and wane or progress steadily. It usually takes a few months to a year after onset for a dog to become unable to walk. Fortunately, dogs with DM do not appear to be in pain. However, if the pet falls she can hurt herself, or if she also has orthopedic problems complicating the situation, she could have concurrent worsening pain.


Since the clinical signs of DM can appear the same as those for other diseases such as a herniated disk, cancer, infection, spinal stenosis, etc. the diagnosis in a live animal is based on excluding these diseases. Diagnostic testing is needed, including physical and neurological examinations, routine blood work, spinal radiographs, as well as possibly myelography, spinal fluid analysis, computed tomography (CT) or magnetic resonance imaging (MRI) scans. Orthopedic problems should also be evaluated.


Unfortunately no treatment has been shown to reverse the signs. DM can be managed but not cured. Supportive treatment can help. A study evaluating combination therapy with aminocaproic acid, N-acetyl- cysteine with vitamins B, C, and E failed to detect a benefit. Minocycline, a tetracycline antibiotic with anti-inflammatory properties, is still being evaluated as part of therapy.

Exercise such as walking and swimming should be encouraged. Physical therapy helps to maintain muscle mass and quality of life. In one study of 50 dogs with DM, those that received intensive physiotherapy had longer survival time (mean of 255 days), compared with dogs that received moderate (mean of 130 days) or none (mean of 55 days). Dogs receiving therapy also maintained their ability to walk significantly longer than those that did not.

Read more or contact Dr. Dana:
Dana Lewis, DVM
Lap of Love Veterinary Hospice
Raleigh, North Carolina  |

Dr. Dana assists families with Pet Hospice and Euthanasia in the Raleigh North Carolina area (Raleigh, Durham, Chapel Hill and the greater Triangle, as well as Wake, Durham, Orange, and Chatham counties. Special arrangements can be made for other surrounding counties and for the Triad area.  

1 comment:

  1. i have a 10 year old rotty with Dm. i was told she wouldnt be able to walk or get around by dec of 2012. Its now march of 13 and she is better than ever. She can get up off of slick floors and everything.what did i do to help her condition? Vet tried everything and recomended acupuncture. My mother said she takes yucca stalk for her painful joints and nerve conditions and it seems to i started giving my rotty a adult size dossage about six capsules a day and the vet was jaw dropped when i brought her in six months later. All symtoms were gone.she can reset her rear paws and everything. My vet is now recomending it to clients now. Hope this helps some one. i talk to people who have lost pets to dm and its so sad when they all say I wish I had talked to you sooner. So Im gonna start posting my story online to help other dog owners.
    Scott tackett


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