Degenerative Myelopathy (DM)


This disease is seen most frequently in German shepherd dogs but can occur in any large breed dog. It may be that what we call DM is actually several disorders lumped under the one term. There is undoubtedly a classic disease in German shepherd dogs but then there may well be one or more similar disorders that affect other breeds. Degenerative myelopathy has an insidious onset, starting with weakness in one rear limb and then progressing to involve both rear limbs. Affected dogs often cross their rear feet as they walk and may also abrade their toes so badly that they bleed. Within 6 months most German shepherd dogs are barely able to use their rear legs without support but they retain awareness and control of urination and defecation. Signs may progress more slowly in other breeds of dog. The biggest problem with DM is that there is no clinical test that can confirm the diagnosis. Therefore the challenge is to be sure that the animal does not have some other cause for its clinical signs such as a disc, a tumor or even myelitis, which is an inflammation of the spinal cord. Usually there are clues from the neurological examination that one of these other diseases is present but this is not always the case. As these other conditions may be amenable to treatment the ideal is to rule them out definitively using either a myelogram, or preferably an MRI combined with a CSF analysis. If there are no other conditions present then DM is the probable diagnosis and there is no treatment that has been shown to influence the outcome. A combination of herbal remedies and other agents has been proposed by Dr. Clemmons at the University of Florida but this therapy is controversial at best.

The prognosis for DM is poor. Most German shepherd dogs have to be put to sleep within 6 to 9 months of the onset of clinical signs. Progression may be slower in other breeds of dog. Complications mainly relate to abrasions of the toes as the dog drags its feet. Incontinence only occurs once the dog is almost paralyzed.

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