Canine Library: Diseases

Intervertebral Disc Disease

Inherent defects may be waiting to cause problems.

The backbone is made up of a series of individual bones (vertebrae) separaled by discs that cushion the bones and allow for flexibility. The outside of the intervertebral discs consists of tough, fibrous material that attaches to the bones above and below it as well as to the muscles, tendons and ligaments of the back. Inside each disc is a jelly-like substance that acts as a cushion. The bony spinal column surrounds and protects the spinal cord (the major nerve cord from the brain).

If the outer layer of a disc is weak, the interior substance bulges out (herniates) and can press on the branches of the nerves or even on the spinal cord. This pressure causes pain, muscle spasms, partial paralysis or, in severe cases, complete paralysis. This usually occurs in the neck (cervical) or lower back (lumbar) vertebrae. As long as there is no permanent damage to the nerves, removal of the pressure allows a return to normal.

In mild cases, treatment with antiinflammatory drugs (such as cortisones) is usually successful. The disc material is reabsorbed, and the covering heals itself. The healed disc is left with much less lubricant, which reduces flexibility, but usually the disc will not herniate again.

When there are more severe neurological symptoms, surgery may be the best treatment. The orthopedic surgeon removes the disc material that is pressing on the nerves. This is major surgery, requiring a great deal of skill and care, and it is done mainly at teaching hospitals where board-certified surgeons are available.

Why the disc coverings weaken is not known, but, as with back problems in humans, they seem to be inherent defects that are accidents waiting to happen. In other words, the potential weakness is present, but some twist, bend or other simple movement initiates the process. Once a disc has herniated, there is increased risk of future episodes. Although disc disease can occur in any dog, some breeds are at higher risk. Dachshunds are most prone to disc disease, and Beagles, Poodles, Lhasas, Shih Tzu and other long, low breeds also seem to have a greater incidence.

Keeping your dog at a proper weight and in good muscular condition can help forestall these episodes. So watch your dog's food intake and weight, and keep it on a regular exercise program.

Author(s): Wilcox, Bonnie, D.V.M.
Publication: Dog Fancy
Issue Date: September 1993


Canine Library: Diseases