Intervertebral Disk Disease in Dogs: An Overview

Dog Breeds

Intervertebral disk disease (IVDD) is a syndrome of pain and neurological deficits caused by degeneration and displacement of all or part of the material inside an intervertebral disk (called the “nucleus” of the disk).

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Definition

Intervertebral disk disease (IVDD) is a syndrome of pain and neurological deficits caused by degeneration and displacement of all or part of the material inside an intervertebral disk (called the “nucleus” of the disk). An intervertebral disk is a pad of fibrocartilage located between adjoining vertebrae, which are the bones that make up the spinal column. Think of these disks as cushions, or shock-absorbers, between the vertebral bones. Intervertebral disks are subject to degeneration, protrusion, extrusion and herniation, in both dogs and in people. When any of these events happen, disk material enters the spinal canal, which compresses the spinal cord and nerve roots and can cause symptoms ranging from pain to complete paralysis. This is called intervertebral disk disease. In people, it is sometimes referred to as a “slipped” or “herniated” disk. IVDD is one of the most common neurological disorders in small companion animals and is reported to affect 2% of the entire domestic dog population.

Causes of IVDD in Dogs

When disks between vertebrae in the cervical (neck) or thoracolumbar (chest and back) areas of the spine degenerate, the inner disk material can protrude or rupture into the spinal canal. This, in turn, can cause localized compression of the spinal cord (called myelopathy) and/or of nerve roots (called radiculopathy) at the site of the disk damage. Two primary forms of IVDD occur in domestic dogs; these are called Hansen Type I and Hansen Type II. Both involve degeneration of intervertebral disks, but the mechanisms of degeneration and the predisposed breeds are different. Hansen Type I IVDD is an acute hernation of the disk that comes on explosively and typically affects chondrodystrophic breeds (those with breed-specific and acceptable hereditary skeletal deformities, such as Dachshunds, Shih-Tzus, Beagles, Pekingese, Poodles, Corgies, Bassett Hounds and dogs with similar characteristics of genetic dwarfism). Hansen Type II IVDD refers to a more gradual, chronic protrusion of disk material that typically affects nonchondrodystrophic breeds, such as German Shepherds, Labrador Retrievers and Doberman Pinschers. Regardless of the type of IVDD, prompt treatment is necessary to prevent progressive neurological damage.

Preventing IVDD in Dogs

Obviously, one important way to prevent traumatic damage to a dog’s spinal cord is to manage its athletic enthusiasm. Regular, moderate exercise is good for healthy dogs, and usually for their owners, as well. Uncontrolled leaping and jumping - especially off of high places like decks, tall furniture, ledges, boulders, pick-up truck beds and the like – is not, especially for dogs with degenerative disk disease. Owners of chondrodystrophic breeds should take special care not to let their dogs jump from high places, as their large bodies and comparatively short legs are especially prone to musculoskeletal and spinal injuries. Obesity should be avoided in any dog. Signs of back or neck pain should be taken very seriously. Owners who suspect a spinal cord injury might want to consult with a veterinarian and perhaps with a veterinary neurologist or orthopedic specialist.

Special Notes

Many dogs with IVDD can be managed without surgery, especially if their disease is diagnosed and treated early in its course. Dogs that have lost deep pain sensation or already have become paralyzed from IVDD have a much more guarded prognosis.

Symptoms and Types