Degenerative Myelopathy - Is Your Dog at Risk?

Close-Up Of Black Dog Sitting Against Closed Metallic Door
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Degenerative myelopathy is a progressive disease involving the spinal cord. It is thought to be an inflammatory, autoimmune disease in which the immune system attacks the dog’s central nervous system. This attack, variable in its presentation and course, leads to a loss of insulation around the nerve fibers (myelin) and of nerve fibers (axons).

The animal can no longer walk once the nerves in the spinal cord are destroyed; without nerve connections, muscles cannot work, and control pathways that make muscles work are located all throughout the spinal cord.

Degenerative Myelopathy in German Shepherds

Here is an interview with Marjorie Zimmerman who lost her beloved pet to this disease.

Q: Marj, tell us a little bit about yourself.
A: I have been owned and loved by German Shepherds since 1967. The rug was ripped out from beneath my feet when my beloved Jack Flash got a diagnosis of a disease I’d never heard of before -- degenerative myelopathy. I may lead an ordinary life, but it isn’t my way to just sit back and accept the inevitable.

Q: How did DM become your “cause?”
A: DM didn't exactly become my cause – it became my enemy.

Jack’s courage and loyalty averted an attempted carjacking. Jack Flash saved my life, but I would be unable to save his. When DM took Jack Flash from me that commenced all out war!

Q: How did you start your war?
A: The more I investigated DM, the more I found it to be a big dark secret – an unmentionable to breeders. When Jack Flash was diagnosed with degenerative myelopathy in 1997, I made up my mind not to accept the neurologist’s dismal statement that there was nothing to be done.

 

My research led me to Roger Clemmons, DVM, Ph.D. He was actively engaged in researching degenerative myelopathy at the University of Florida, as he had been doing throughout his career. While no cure was on the horizon, Dr. Clemmons had instituted a treatment program to slow the progression of DM.

Shortly after our first communication, I founded the Degenerative Myelopathy Support Group.

Through his help, members are able to cope with the difficult times and the debilitating problems. 

Q: How did that treatment program work for Jack Flash?
A: Jack outlived his 2- to 3-month prognosis by 13 months, while maintaining quality of life. I promised Jack, as his eyes closed for the last time, that in his honor I would continue to battle DM, until the disease that took him from me would also be permanently laid to rest.

Q: In which breeds is it most common?
A: So far, the following breeds have been found to develop the same type of DM as that seen in the German Shepherd Dog: Belgian Sheepdog, Old English Sheepdog, Weimaraner, Rhodesian Ridgeback, Chesapeake Bay Retrievers, Labs and possibly the Great Pyreenes. Confirmation of diagnosis in other breeds is very important.

It is seen with relative frequency in German Shepherd Dogs; therefore, it appears there is a genetic predisposition in this breed. While many breeds suffer from a myelopathy that is progressive, the particular degenerative myelopathy of the German Shepherd Dog is unique, as it is believed to be an autoimmune disease.

Q: What signs and symptoms are seen in DM?

A: DM is very subtle. It comes on slowly and gradually, making the disease horribly insidious. It may attack one or both sides of the body and presents with waxing and waning of the following symptoms, or the following combinations: Hindquarter weakness, rear limb ataxia (unsteadiness), loss of balance, stumbling, difficulty rising up or laying down, knuckling (toes bent under while walking), rear legs crossing under body, rear leg drag, spinal ataxia, hoarseness of bark, limp tail, muscle wasting, and/or the loss of rear musculature.

This debilitating illness leads to paralysis and incontinence in its final stages.

Q: How is diagnosis confirmed? 
A: DM used to be a “rule out” disease. That is no longer the case. There are now specific tests to “rule in” DM. While there remains no one specific test for DM, there are a combination of tests which help confirm the diagnosis, while also looking for other diseases that may mimic its clinical signs or even co-exist with DM.

Tests for DM include:

  1. Physical examination: including history (susceptible breed included). A  physical exam should include routine blood tests (CBC, Chemistry Profile and UA), radiographs of the chest and abdomen and abdominal ultrasound. Other tests may be indicated based upon physical findings. Splenic masses are not uncommon in DM patients, so abdominal palpation, radiographs or (preferably) ultrasound can be important initially and for monitoring patients.
  2. Neurological examination: looking for a non-localizing posterior paresis. Most cases of DM present as a non-localizing (no pain) upper motor neuronal dysfunction (rear leg reflexes are present to hyperactive) to the rear legs, suggesting the problem is in the white matter of the TL spinal column.
  3. Electromyogram: including a Spinal Evoked Potential test. In uncomplicated DM cases, the needle EMG, motor nerve conduction velocity and repetitive nerve stimulation responses are normal, but the spinal evoked potential is abnormal. In inter-vertebral disc disease and myelitis, the EMG is abnormal (focally), but the spinal evoked potential is normal. In polyradiculoneuropathy, the EMG is abnormal, diffusely, and the spinal evoked potential is normal.
  4. Lumbar CSF (cerebral spinal fluid): analysis with appropriate titers and cholinesterase level. In uncomplicated DM, the lumbar CSF protein is elevated, the CSF cell count is normal, the titers are negative and the cholinesterase is elevated. In infectious or inflammatory diseases, the protein and cholinesterase levels are also elevated, but the cell counts and titers are also abnormal. In inter-vertebral disc disease, the protein and cell counts are minimally elevated and the titers and cholinesterase levels are normal.
  5. Spinal Radiographs: (regular and appropriate imaging--myelogram or MRI) Spinal column imaging only shows signs of age, unless there are complications of DM.

Some DM patients do not handle myelography very well and their neurological symptoms can worsen or they may become paralyzed. On the other hand, myelography can be a very important test when looking for surgical disease. It is not wrong to rule out the presence of surgical disease. DM is one of the non-surgical diseases; however, it can be better to start testing for DM with the least invasive tests, leaving the more serious tests for last.

Q: What is the prognosis for a DM dog?
A: There is progression to paralysis in 3-6 months when DM is untreated. With appropriate treatment, this can usually be doubled. Some dogs will not progress with treatment. Almost all dogs will progress without it.

Once hind limb paralysis occurs, there is another progressive course toward forelimb paralysis. Eventually, there is another progressive course towards brainstem failure. Few dogs will survive beyond 2 years without treatment.

Although the only organ affected by DM is the spinal cord and brainstem (although changes are seen in the white matter of the cerebrum), the ravages of being paralyzed can result in failure of the kidneys, heart and/or lungs. Too often the veterinarian, who does not wish to put the dogs through any further testing or the owner through more expense, ignores these additional problems. Frequently, problems may be chalked up to being part of DM, which is certainly not the case.

It is important to monitor the health of a DM dog and treat those things that may be treated, including additional neurological problems.

A word about parasite prevention in the DM dog: To help a DM dog live a longer life, flea prevention and heartworm medications need to be examined. Dogs must receive flea and heartworm prevention if they live in areas where these are problematic. Dr. C. feels Revolution is best for a DM dog, with Frontline added as needed. Otherwise, a combination of Frontline and Filarbits PLAIN (not plus) is preferable.

Q: Is Dr. Clemmons still involved with DM dogs?
A: Dr. Roger Clemmons is, in my opinion, the most knowledgeable person to consult when it comes to DM in the German Shepherd Dog. He is a DVM, Ph.D., and an Associate Professor of Neurology & Neurosurgery, Small Animal Clinical Sciences, at the University of Florida, Gainesville. Now he is studying the effects of new drugs in relation to DM, hoping to slow the progression of the disease further. He is also searching for a genetic (DNA) “fingerprint” for DM to see if “at-risk” patients can be identified before developing signs.

Dr. Clemmons continues to research ways of combating DM. He has written to the AKC Canine Health Foundation and his pre-proposal has been reviewed and approved for possible funding.

Q: Is there a way we can try to prevent DM in our dogs?
A: Dr. C. goes by the old saying, “An ounce of prevention is worth a pound of cure.” He believes diet may contribute to the development of autoimmune problems. He prefers a more natural diet and even has a home cooked diet on his website. Also, antioxidants may play a major role in the prevention of autoimmune disease, counteracting the damage done by free radicals. He combines a traditional allopathic approach with an alternative holistic approach recommends the following to keep a dog healthy:

  • High potency B-complex (B 50)
  • 400 IU of vitamin E daily (over 2 years of age, give 800 IU)
  • 250mg vitamin C twice a day (over 2 years of age, give 500mg)
  • 100mg of selenium daily (over 2 years of age, give 200 mcg)
  • 500mg of borage oil twice a day
  • 12,500 IU Beta Carotene (over 2 years of age, give 25,000)
  • 1mg/kg (or 1 capsule) Ginkgo biloba 2-3 times a day
  • 1 capsule (or cup) Green tea, twice a day
  • 50mg grape seed extract, once a day
  • 2 sardines or 1 T ground flax seeds
  • 1-2 Raw garlic cloves (crushed)

Note: Add the supplements gradually, one new supplement every few days. That way, if something does not agree with your dog, you will know what has caused the problem. Overloading the digestive system of a dog with many new items all at once is never advised. Vitamin C is not recommended for dogs with IBD. Also:

  • Try to avoid exposure to pesticides.
  • Check the rear nails of your dog once a month. Look for uneven wear on the nails, which may be an early tip-off to DM.

Q: Is it safe to breed a DM dog?
A: Please do not breed a dog that has degenerative myelopathy. While DM may not be called a genetic disease, it does seem to involve genetic factors. Until these factors are better understood, responsible breeders should not pass on the genetic predisposition. Once the genetic profiles of DM dogs are scientifically understood, this issue may be clearer. Right now, caution is our best ally. 

Q: You said there might be a genetic predisposition to DM. Tell us about your Pedigree Project.
A: I am gathering pedigrees of DM dogs in an attempt to establish a database. One day this pedigree collection may provide valuable insight into which dogs may be at risk for developing DM. If we can uncover those at risk, we may be able to provide early intervention or prevent the disease from developing.

Many support group members have posted the pedigrees of their DM dogs on my message board in the Pedigree Forum. In addition, some have submitted pedigrees, privately, wanting them to be revealed only to researchers, rather than the general public.

When pedigrees are publicly posted, knowledgeable breeders are able to see which combinations of breeding have produced a DM dog/dogs. There is no shortage of breeding animals, and neither sire nor dam must be cut from a breeding program. However, this information provides responsible breeders with knowledge about the combinations that could lead to a DM litter. Sibling DM is not uncommon, and the posting of pedigrees can make for wiser choices and healthier pups. It would be great to have a handle on which combinations of lines might have the highest risk for developing DM.

Q: Tell me more about the questionnaire appearing on your website.
A: As my knowledge of DM has grown, so has the questionnaire on my site. One question leads to another and, in science, often the situation must be examined microscopically. My survey is anecdotal and not scientific. However, I have begun to uncover possible patterns. I do hope that this information can, in the future, provide valuable data to a scientific study.

The more people with DM dogs who participate in my surveys, the more information I can glean as to the possible “who, what, when, where and why” of DM. Please, help spread the word – to your friends, associates, clients and animal health care professionals.

Q: How can we help?

  • Support DNA/fingerprint research and testing.
  • Pick a month in your local clubs to specify as DM Awareness Month – hold fund-raisers, auctions, or educational seminars.
  • Ask your parent club to earmark funding for DM research.
  • Petition charitable organizations, such as the Morris Foundation, the AKC Canine Health Foundation, etc. for grant monies for those who are experienced in DM research.

And please, raise group funds for or send an individual, tax-deductible check or money order to:
Dr. Roger Clemmons
PO Box 100126
College of Veterinary Medicine
University of Florida
Gainesville, FL 32610-0126

Specify on your check or money order that the donation is to be used for Dr. Clemmons’ Research, ONLY.