Imagine the confusion and fear you'd be feeling if you were approaching your middle years and suddenly developed difficulty walking. The same bewilderment hits middle-aged dogs who have a progressive nerve disorder known as degenerative myelopathy (DM). The disease causes the dog to slowly lose coordination of its hind legs, which also become increasingly weak. It's caused by a deterioration of structures within the spinal cord that are responsible for transmitting nerve impulses. This degeneration can occur anywhere along the spinal column, but usually affects the lower back.
Degenerative myelopathy is only found in dogs that are at least 5 years of age or older. The cause is not yet understood; although it's theorized that it could be related to an autoimmune response, in which the body immune system mistakenly attacks its own cells. [...]
Nothing is as horrible for a dog owner as to see their beloved pet slowly lose the ability to move without being able to do anything about it. Unfortunately for those dogs diagnosed with degenerative myelopathy this is just the case. The disease causes a malfunction in the signals between the brain and the hindquarters, resulting in gradual loss of functioning of the back legs that is similar to a paralysis.
The breeds most often associated with degenerative myelopathy are not typically the long backed breeds, although it would be logical to assume these breeds would have the most problems. German Shepherds, Irish Setters, Chesapeake Bay Retrievers and the Welsh Corgis are the breeds most commonly diagnosed with the condition. Since it is more prevalent in specific breeds there is likely a genetic component to the condition although it has not been isolated at this time. [...]