Degenerative myelopathy (DM) is the name given to a degenerative spinal cord disease of dogs similar to Lou Gehrig’s disease (amyotrophic lateral sclerosis; ALS) in people. Any dog can get DM, but some of the breeds most implicated include the German shepherd, Pembroke Welsh corgi, Boxer, Chesapeake bay retriever, Bernese mountain dog, Rhodesian ridgeback, and Cavalier king charles spaniel. Although it is believed that DM has a heritable basis, meaning there is a genetic component, the clinical signs of DM do not appear until later in an animal’s life, typically around 7-11 years of age.
The first sign of DM is often scuffing of the toenails while walking, or slipping of the hind limbs on slick floors. The signs of DM progress slowly over several months to include profound weakness in the hind limbs and, typically within 6-12 months, the inability to walk in the hind limbs. Eventually, the front limbs also become affected. Unfortunately, there is no treatment for DM. Physical therapy and exercise is recommended to keep dogs with DM as strong as possible, but eventually all affected dogs will lose the ability to walk.
There is no test for DM in a living patient. Instead, the focus is to rule-out the presence of other, more treatable conditions such as intervertebral disc disease. This is done by performing an MRI and spinal tap.
If you or your veterinarian believes your dog may have DM, you may schedule a consultation with our Neurologist by calling us at our Manchester or Newington location today.
What about the “DM test”?
A genetic test is available for a gene associated with the development of DM in some dogs. This gene, SOD1, is mutated in some dogs with DM and it is also mutated in one form of ALS in people. It is important to know that this is not a test for DM, only for a gene mutation which has been associated with DM. There are dogs who test “at risk”, meaning they have 2 copies of the mutation, who never develop DM, and there are dogs who test “clear”, meaning they do not carry the mutation, who do indeed go on to develop DM. If DM testing is done in a patient, the results must be used as part of the entire clinical picture of a patient (together with a complete neurologic exam and MRI of the spine), not on their own.