Intervertebral Disk Disease Signs, Symptoms & Treatment Options for Pets

The intervertebral disks sit between the vertebrae in the spine. Disks are the shock absorbers of the spine. They have two portions, an outside fibrous covering (the annulus fibrosis) and an inside, more gelatinous portion, the nucleus pulposis.

Dachshunds, Cocker Spaniels, Lhasa apsos, Pekinese, and Beagles (among others) appear predisposed, as their disks age or degenerate quicker than most dogs. Young to middle-aged dogs are most commonly affected. Dogs less than 1 year of age rarely have intervertebral disk disease. Geriatric dogs are occasionally affected.

When the intervertebral disks become damaged, this is referred to as intervertebral disk disease (“Disk disease”, “Slipped disk”). As disks degenerate, they lose water content, and become less able to withstand compression. They become less able to withstand forces placed upon them. If too much force is placed on them, they can be squeezed and expand or rupture. This rupture usually occurs in an upward direction, and the disk extrudes into the spinal canal toward the spinal cord. Signs develop either because of the force of the disk material hitting the cord, or due to the disk material compressing the spinal cord.

Intervertebral disk disease can occur in any area of the spinal cord. Signs of a disk problem range from being painful to being unable to move. The more damage there is to the spinal cord, the worse the clinical signs. Pets with severe spinal cord damage from disk disease lose the ability to move and to feel (conscious sensation) their limbs. If a pet has lost the ability to feel in the legs, its chance of walking again is about 50%. If a pet can still feel in the legs, even if they can’t move, there is a greater than 80% chance it will walk again after surgery (if performed).

The diagnosis of disk disease is based on clinical signs initially. To prove that a disk is pressing on the spinal cord, a special X-ray study known as a myelogram is often necessary. CT and MRI are other techniques that can be used to see the ruptured disk. For the myelogram, CT or MRI the patient needs to be very still, therefore, anesthesia is necessary to perform these tests.

General guidelines have been established for therapy depending upon severity of clinical signs. Mildly affected pets (pets with pain alone or mild weakness but able to walk) may be managed with cage confinement for at least two weeks. Strict confinement is very important to allow for healing of a partially damaged disk. If after 2 weeks signs persist or if the pet worsens during this time, surgery should be considered sooner. More severely affected pets (those who are unable to stand and walk) are considered for surgery. The surgery is performed to remove extruded disk material from around the spinal cord, relieving the compression and giving the spinal cord the best chance at healing.

Additional information regarding Intervertebral Disk Disease (and other common surgical disorders in dogs and cats) can be found on the website of the American College of Veterinary Surgeons.