What is it?
Canine degenerative myelopathy is a progressive disease of the spinal cord seen in older dogs, typically between the ages of 7 and 14 years. While the actual cause is unknown, one theory is that the myelin sheath that protects the spinal cord is attacked by the immune system, similar to multiple sclerosis or Lou Gehrig's disease, resulting in a loss of communication between the nerves in the lower body and the brain. Other theories suspect toxicity or vitamin deficiency.
This disease has a known genetic link; therefore prevention with prudent genetic testing prior to breeding is important. This test is available from theOrthopedic Foundation for Animals and is a simple cheek swab with a q-tip that is then submitted for genetic testing. A blood test through your veterinarian is also available. Tests need to be performed on both parents to determine what the risk of passing on DM to any offspring might be: could they be a carrier, affected or be negative for the DM link. For example:
- If neither parent carries the link, then all puppies will be clear.
- If one parent carries the link (is a carrier) and one is clear, then 50% of the puppies will be clear and 50% will be carriers.
- If both parents are carriers, then 25% will be clear, 50% will be carriers and 25% will be affected by the disease.
- If one parent is affected and if one parent is a carrier, 50% of the puppies will be carriers and 50% will be affected.
This outlines how important the health of breeding pairs is to the future health of the breed. This disease is a progressive, non-curable condition; anything that can be done to prevent this devastating diagnosis for the owners and the dogs affected by this condition should be done.
It is important to note that this disease is not painful, but in compensating for the weak hind end, pain can occur in the neck, shoulders and front limbs. This disease unfortunately progresses to complete paralysis, with incontinence and significant difficulty walking and balancing. If it progresses further, the front legs are affected, and in very late stages the respiratory muscles are affected. Progression of the disease varies, with symptoms increasing within a couple of months up to 3 years or more, typically paralysis will occur within 6 months to one year.
Diagnosis is usually made only when other causes of the gait disturbance have been eliminated. Knowing the genetic makeup for the links for degenerative myelopathy may help make the diagnosis as well.
Unfortunately there is no treatment that can stop the progression of degenerative myelopathy. Care is focused on comfort and maintaining mobility through physiotherapy, water therapy, use of
harnesses and slings, and good general nursing care, like assisting with incontinence issues. Exercise through walking with a harness, sling or cart is important to maintain health of the dog with degenerative myelopathy. Physiotherapy is also available to assist in prolonging the length of time that the dog can remain mobile.
Properly fitted assistive equipment, like carts/wheelchairs, and good nursing care can extend the life of the dog by up to 3 years, versus dogs that do not receive any physiotherapy who are typically totally paralyzed by 6 months to a year. Early intervention is key in maintaining quality of life. Interestingly, in the 2010 Kerry Blue Terrier Foundation health survey, only one dog was found to have passed away secondary to degenerative myelopathy. If anyone is in need of an assistive cart, the Kerry Blue Terrier Foundation has one that can be loaned out as needed. For information about carts, wheelchairs and other items to help your Kerry, go to www.handicappedpets.com
Here is a KB T named Kelly doing her hydrotherapy work with her therapist to slow down the effects of DM. Kelly recently started showing the classic
signs of DM. In addition to other diagnostic tools, testing her blood showed that she inherited the DM gene from both of her parents, putting her
"atrisk" for the disease. Kelly seems to enjoy her weekly hydrotherapy, which has resulted in much improvement in her symptoms since the start
of the therapy. The therapy involves Kelly being on a treadmill in 90F degree gently moving water. Kelly actually looks forward to her weekly sessions.