Intervertebral Disc Disease (IVDD)

The spinal column is made up of a number of small bones called vertebrae lined up like building blocks. A hole in the center of each vertebrae forms a tunnel through which the spinal cord passes. The spinal cord is extremely important, as it carries the messages from the brain to the rest of the body. The spinal cord is extremely delicate, and being surrounded by the bony vertebrae helps to protect it. Between each pair of vertebrae, just underneath the spinal cord, is a little cushion, called an intervertebral disc. Discs cushion the vertebrae from one another and provide flexibility to the spine during movement.

As a part of the normal aging process, these discs deteriorate, resulting in so called intervertebral disc disease (IVDD). Normally, each disc consists of an outer fibrous ring and inner gelatinous center (a good analogy would be a jelly doughnut). With age, this “doughnut” changes in its consistency: the outer fibrous ring becomes fragmented and the inner “jelly” center hardens to become gritty. The fibrous ring may no longer be able to hold this hard center in place, and movement of the vertebrae on either side may suddenly squeeze the disc out of its normal position. This material may cause damage to the nerves from the spinal cord or to the spinal cord itself.

This type of disc disease may occur in dogs of any age or breed, but occurs most commonly in the “short-legged” breeds (e.g.: Dachshund, French Bulldog, Welsh Corgi, Pekingese) and some other small breeds such as the Poodle and Cocker Spaniel. It may also occur in any other breed of dog.

These symptoms (pain, weakness, ataxia, and possibly paralysis) indicate the dog has a problem affecting the spinal cord, but not the exact location or cause of the problem. Symptoms of intervertebral disc disease include:

  • Neck and/or back pain
  • Weakness
  • Poor coordination of the limbs, and possibly weakness and/or paralysis

Other diseases, including fractures, abnormal clot formation, infectious diseases, and cancers, may all produce similar symptoms. Tests used to determine the exact cause of the symptoms, as well as the exact parts of the spine involved include radiographs (often under anesthesia) and bloodwork. Commonly, advanced diagnostic procedures are required to provide important information about the severity of IVDD in individual patients. Some of these tests include:

  1. Myelography, a procedure in which special dye or contrast is injected around the spine.
  2. Computed tomography (aka: CT or CAT scan), used to obtain a more detailed image of the spine.
  3. “Spinal tap” to evaluate fluid surrounding the spinal cord to investigate the possibility of infection.

Your veterinarian will determine if your pet’s disc disease is best managed medically or surgically. Medical therapy involved strict rest, aggressive pain management, and possibly administration of anti-inflammatory medications. Although these interventions do not correct the spinal cord compression, it may temporarily reduce some of the pain and swelling around the spinal cord, permitting the ruptured disc to “heal.” Strict adherence to your pet’s rest recommendations is most important to help him/her to heal.

Surgical therapy is commonly needed. The surgery most commonly performed involves removal of some vertebral bone and the disc material compressing the spinal cord. This surgery is called a laminectomy. For animals undergoing a laminectomy, the speed of recovery and the extent to which normal function of the legs is regained depend on many factors, including the degree of the damage to the spinal cord and the length of time the spinal cord has been compressed by the disk material. Animals exhibiting severe neurological signs (e.g.: paralysis), a rapid onset of symptoms (hours), and a long period of time before surgery generally have a prolonged recovery period, and may have varying degrees of permanent damage.