Degenerative myelopathy, or DM, is the veterinary term for a disease commonly called hind-end weakness. If you have a dog, or are thinking about getting one, hind-end weakness is a dog disease you should know about. I have most often heard of it affecting the German Shepherds, but authoritative sources indicate that it has been documented as afflicting a number of breeds.
Dr. Bernhard Pukay, writing in the Ottawa Citizen, discusses the cause of hind-end weakness, and some of the things you can do to slow the progression of the disease.
Hind-end Weakness is a Dog Disease You Should Know About
Q: A few months ago, we had to euthanize our 12-year-old German shepherd after she gradually lost the use of her back legs. She was eventually unable to walk and lost control of her bowel movements. She was diagnosed with degenerative myelopathy and because her prognosis for a complete recovery was poor and she failed to respond to treatment, we had to have her put to sleep.
We are now considering getting a brand new German shepherd puppy but we read that German shepherds in general are particularly susceptible to hind end problems such as degenerative myelopathy as they get older. Is this true of all German shepherd dogs or is it a specific genetic defect that occurs only in some shepherds? Is there any way to prevent this disease from occurring?
A: There are several neurological conditions that manifest themselves with hind end weakness or paresis (i.e. partial loss of voluntary movement or impaired movement). Spinal or brain tumours, intervertebral disc disease (“slipped disc”), lumbo-sacral stenosis (narrowing of the spinal canal), and fibrocartilaginous embolic myelopathy (a piece of disc material plugs a blood vessel causing spinal cord damage) can all lead to hind end paresis or paralysis.
The specific degenerative neurologic disease called degenerative myelopathy (DM) that your previous dog had occurs more often in German shepherds than any other breed of dog, suggesting a genetic predisposition. The age of onset for DM is usually four to 14 years of age and has been reported on rare occasions in other dog breeds, including Labrador retrievers, collies, huskies, Weimaraners, Old English sheep dogs, Rhodesian ridgebacks and Great Pyrenees).
Degenerative myelopathy is thought to be an autoimmune disease that attacks the central nervous system of patients, leading to a loss of insulation around the nerve fibres (a process called “demyelization”) and progressive spinal cord damage. The cause is not known, but genetic, toxic, and environmental factors are suspected.
Dogs with DM tend to show gradual hindquarter ataxia (unsteadiness) and weakness that can either wax and wane or become progressively worse over time. Most affected dogs lose the function of their hind legs within six months to two years after onset. Diagnosis can be difficult since X-rays, MRI’s, CT scans, myelograms (when a dye is injected into the space around the spinal cord) and other tests are often normal.
While there is really no proven effective treatment currently available, two medications are reported to prevent progression or lead to clinical remission in some patients: aminocaproic acid (EACA) and n-acetylcysteine (NAC). No effective surgery is currently available and steroids are ineffective.
Regular aerobic exercise such as walking and swimming has been shown to be helpful in preventing chronic degenerative diseases by improving muscle performance, memory and blood flow to the brain and this appears to be the case with DM as well.
Recent research has suggested that dietary regulation can also have a strong influence on the development and progression of chronic degenerative diseases and this may include DM.
To read more of what Dr. Pukay has to say regarding things you can do to lessen the severity of this disease, and things you should discuss with your veterinarian regarding degenerative myelopathy, click here. Hind-end weakness is a dog disease you should know about so you can be prepared to reduce your dog’s suffering, if it contracts the disease.