What is Degenerative Myelopathy?
With diseases like Degenerative Myelopathy, which have no cure, one of the most important coping mechanisms for owners can be information. It was with this in mind that this put together this information. There are many decisions that will have to be made at each stage involving not only your dog’s quality of life but the owner/caregiver’s quality of life.
Canine Degenerative Myelopathy (DM) is a progressive disease of the spinal cord and ultimately the brain stem and cranial nerves which, at it’s end stages, results in complete paralysis and death. The closest human equivalent may be Amyotrophic Lateral Sclerosis, or ALS, also known as Lou Gehrig’s disease. The same gene mutation is implicated in both diseases.
DM was first described as a specific neurological disease in 1973. The cause of the disease is not known although recent research has found a possible genetic link. The mutated gene has been found in 100 breeds including Cardigan and Pembroke Welsh Corgis, Chesapeake Bay Retrievers, Irish Setters, Boxers, Collies, German Shepard Dogs, and Rhodesian Ridgebacks. In a recent study 2% of German Shepard Dogs were identified as having the disease. Only 0.19% of dogs in general have the condition.
The disease typically appears at between 5 and 14 years of age depending on the breed of dog. Both sexes appear to be equally affected.
What is Actually Happening?
DM begins in the spinal cord in the thoracic, or chest, region. The white matter of the spinal cord, which contains the nerve fibers responsible for transmitting movement commands from the brain to the limbs and sensory information from the limbs to the brain, degenerates. One theory for the cause of DM is that the immune system itself attacks the nervous system causing the degeneration. The degeneration consists of demyelination of the nerves and actual loss of nerve fibers. If you think of the nerve fibers as an electric wire, the myelin (a white fatty material that surrounds the nerve fibers) would be the insulating coating on the outside of the wire. Without this coating, nerve impulses cannot be transmitted.
According to Dr. Joan R. Coates, one of the leading experts in this condition, DM is not an inflammatory disease. She states that DM is similar to oxidative stress which characteristically has a release of free radicals resulting in cell degeneration.
Degenerative Myelopathy has a slow, insidious onset with a slow progression of weakness. It is not uncommon for the signs to progress slowly, plateau, and then start to progress again. These symptoms often begin in one rear leg and then eventually involve both rear legs as the disease progresses; alternatively, it could affect both rear legs at the same time. This condition is NOT painful. As a result, with appropriate physical therapy and nursing care, patients with DM can still have a good quality of life for a significant length of time.
- Exercise will help to prolong you dog’s muscle mass and mobility.
- Aquatic therapy of either walking or swimming can even be more useful than walking. To date, professional canine rehabilitation (physical therapy) is the only treatment that has been shown to improve quality of life and longevity.
- Increased awareness of the level of nursing care necessary to prevent secondary complications such as decubitus ulcers, urinary tract infections and foot damage is also very important.
- The use of a harness to assist in your dog’s mobility and later in your ability to move your dog around are also considerations.
- A cart or a progression of carts will not only improve your dog’s mobility but his or her quality of life.
- Dr. Roger M. Clemmons, an associate professor of veterinary neurology and neurosurgery at the University of Florida’s College of Veterinary Medicine, suggests that a combination of “diet, exercise, supplements and medications” may “slow or stop the progression of the clinical signs.” These statements have not been confirmed by peer-reviewed, controlled studies. Anecdotally, we have seen no significant difference in patients that were given these supplements/medications compared to those patients that did not receive them.