Myelopathy

Patty Khuly

Summary

Myelopathy is a general term used to help describe nearly any disease of the spinal cord. For example, spinal cord trauma is one manifestation of myelopathy. Myelitis, an inflammatory process of the spinal cord, is another. And if the spinal cord disease is the result of an aberration of the circulatory system, it’s referred to as vascular myelopathy.

Though a wide variety of disorders fall under the umbrella of “myelopathy,” the most notorious cause of this condition in pets is known as degenerative myelopathy.

Also called “chronic degenerative radiculomyelopathy,” and “German shepherd dog myelopathy,” degenerative myelopathy (DM) is a relatively uncommon neurological disease characterized by progressive weakness and loss of normal function in the hind limbs of affected dogs. This disease is treated in more detail in another article in this library.

Despite the notoriety of DM, other causes of myelopathy are far more common. These include the following, for example:

Symptoms and Identification

The appearance of myelopathy will depend somewhat upon the type of disease process (for example, traumatic vs. inflammatory), but the exact location of the lesion is a far better predictor of the animal’s clinical signs, as is the extent of the damage done. Signs may include the following:

  • Ataxia (ambulating off balance)
  • Altered reflexes
  • Reduced sensation
  • Generalized weakness
  • Incontinence (fecal and/or urinary)

Diagnosis is achieved through a detailed history-taking, a basic physical examination, and thorough neurological examination. X-rays and basic labwork (CBC, blood chemistry, urinalysis) are always undertaken to rule out any other obvious causes. Sometimes more advanced imaging (such as MRIs, CT scans and myelography) are in order, as may cerebrospinal fluid analysis (obtained via “spinal tap”).

Affected Breeds

German Shepherds and German shepherd mixes seem most predisposed to DM, but the disease has also been reported in a number of breeds including the Kerry Blue Terrier, Collie, Siberian Husky, Belgian Shepherd, Old English Sheepdog, Labrador Retriever and Chesapeake Bay Retriever.

In the case of IVDD, a genetic predisposition is known to exist as well. This disease is common in the Dachshund, along with many other chondrodystrophic breeds of dogs. These include the Basset Hound, Beagle, French Bulldog, Lhasa Apso, Pekingese, Pomeranian, Shih Tzu, and Welsh Corgi. Cocker Spaniels, Cavalier King Charles Spaniels and other semi-chondrodystrophic breeds are also predisposed. Doberman Pinschers are the only non-chondrodystrophic large breed dog to be predisposed to this disease. It’s referred to as “Wobbler’s disease” in this breed.

Myriad other less common or less notorious causes of myelopathy may also prove heritable.

Treatment

Treatment of myelopathy depends wholly upon its cause.

Veterinary Cost

The cost of veterinary care for myelopathy depends almost exclusively upon its cause, its severity, and its treatability.

For example, because treatment options for DM are so limited, veterinary cost is typically relegated to diagnosis, which normally includes X-rays and typically involves a neurologist’s consultation. In some instances, expensive imaging studies may be employed to rule out diseases with similar signs. In these cases the cost of diagnosis may reasonably rise to $2,000 to $4,000.

Severe IVDD, however, can in many cases require the same expenses of DM but since treatment can often be surgically achieved, its price tag can climb precipitously alongside its treatability.

Prevention

Prevention of myelopathy is not typically considered feasible. Restricting the breeding of dogs whose myelopathies are genetic in origin (as with DM and IVDD) is the only known means of prevention.


References

LeCouteur, R.A., Child, G. Diseases of the Spinal Cord. In S.J. Ettinger and E.C. Feldman (eds) Textbook of Veterinary Internal Medicine, pp.650-652. W.B. Saunders Co., Toronto.

Clemmons, R.M. 1992 Degenerative myelopathy. Vet Clin North Am 22(4):965-971