Degenerative Myelopathy

Degenerative myelopathy is a slow, progressive spinal cord disorder of unknown cause that is most commonly seen in aging German shepherds and a few other large breeds of dogs. Effective therapy has not been reported. Most dogs deteriorate over the course of 6 to 12 months and are eventually euthanized.

The cause of the condition is unknown, although it is believed to be an autoimmune disease – a condition in which the body's immune system begins to attack its own nerve cells. The age of onset is 5 to 14 years, with an average age of 9 years. Males are affected more than females.

The disorder is seen almost exclusively in German shepherds, although it has been diagnosed in a few other large breed dogs, such as Belgian shepherds, Rhodesian ridgebacks, standard poodle, Boxer, Chesapeake Bay retriever, Irish Setter, collies and Weimaraners. Other breeds affected include Pembroke and Cardigan Welsh corgi. The high incidence in German shepherds suggests a genetic basis for the disease. 

The disease is slowly progressive. Affected dogs get progressively weaker and more uncoordinated as the disease process progresses. Many dogs progress over 4 to 6 months from the time of initial diagnosis. 

What to Watch For

Progressive weakness of the hind limbs

Dragging nails

Difficulty rising

Difficulty jumping

Stumbling

Knuckling of the toes

Wearing of the inner digits of the rear paws

Loss of muscle in the rear legs

Tremors of rear legs

Eventual urinary and fecal incontinence

The front legs can be affected in late stages of the disease

Diagnosis

Diagnostic tests are needed to identify degenerative myelopathy and rule out other diseases with similar clinical symptoms. Diagnostic tests include:

Complete medical history and physical examination. Degenerative myelopathy should be suspected in any middle aged German shepherd with progressive weakness and loss of coordination in the rear legs. 

A complete neurologic examination including assessment reflexes and pain sensation is key to making a diagnosis of degenerative myelopathy.

Routine x-rays should be taken to rule out orthopedic problems that may have similar signs.

X-ray contrast studies in which a dye is injected around the spinal cord may be necessary to rule out other causes of progressive weakness and loss of coordination. 

A spinal tap may give some useful information for making a diagnosis.

Treatment

There is no effective treatment for degenerative myelopathy. A few treatments have been recommended, but no controlled studies have been performed to show any proven benefit. 

These treatments include:

Vitamins and other supplements

Aminocaproic acid

N-acetylcysteine

Glucocorticoids

Special homemade diet

Exercise and physical therapy program

Excellent nursing care including padded surfaces, slings, good traction and keeping your dog clean and dry. 

Home Care

Give all medications and supplements as prescribed. Exercise appears to be helpful in delaying the progression of the disease. Dogs should be placed on an increasing, alternate-day exercise program including walking and swimming, if possible.