Cervical Intervertebral Disc Disease in Dogs

What is cervical intervertebral disc disease?

The spine is like a string of pearls with bony vertebrae separated by intervertebral discs.

The intervertebral discs allow movement in the spine and act as shock absorbers between the vertebrae. Each disc is composed of a central, gel-like area called the nucleus pulposus and an outer fibrous ring called the annulus fibrosis.

If the disc degenerates or is damaged in some way, the disc may bulge (like a jelly-filled donut), putting pressure on the spinal cord and/or the roots of the spinal nerves that come off the sides of the spinal cord. This pressure can cause symptoms ranging from severe pain to weakness to paralysis.

The bulging disc may be due to the bulging of the annular ring (protrusion), or from a rupture of the annulus where the nucleus material bulges out (extrusion). A disc that bulges without rupturing is more typical of chronic disc degeneration and is called a Hansen type II. An acutely ruptured disc is called a Hansen type I.

Is there a genetic or breed predisposition for cervical intervertebral disc disease?

Several dog breeds seem to experience the condition more frequently, but it is unknown whether it is inherited genetically. Dog breeds with long backs and shortened and bowed legs, like the Pekingese and dachshund, have faster disc deterioration than other breeds. Studies in dachshunds have shown a possible genetic component to disc degeneration.

"Dog breeds with long backs and shortened and bowed legs, like the Pekingese and Dachshund, have faster disc deterioration than other breeds."

Hansen type I disc disease is most common in breeds with long backs and short legs. It occurs most commonly in younger dogs, 3–6 years of age. The most affected breeds are dachshunds, beagles, and poodles. 

In contrast, Hansen type II disc disease is most common in large-breed dogs like Doberman pinschers. These dogs tend to be a bit older, ranging in age from 8 to 10 years of age. 

What are the signs of cervical disc disease?

The severity of a dog’s clinical signs depends upon several factors, including the rate and volume of disc protrusion or extrusion, the pressure on the spinal cord and/or nerve roots, and the suddenness of the disc material extrusion.

The most common signs include:

• Stiff neck with reluctance to move the head and neck
• Neck pain
• Altered walking
• Lowered head stance, with muscle spasms of the head, neck, and shoulders
• Weakness or partial paralysis in all four limbs, known as tetraparesis (10% of affected dogs)

Examination will reveal neck pain with flexion and extension of the neck, turning the neck from side to side, or by deep palpation of the cervical muscles. Over time, there will be a loss of muscle mass over the shoulders. There may be front leg lameness, such as knuckling or weakness, because of pressure on the nerve roots.

A more severe disc disease scenario involves partial paralysis in both front and/or rear legs. The nervous system symptoms may be confined to only one side of the body, involving the front leg and rear leg on that side.

Are there other risk factors for bulging or ruptured intervertebral discs?

Both obesity and repeated traumatic events in the predisposed breeds may enhance the risk of disc disease.

How is cervical intervertebral disease treated?

Conservative management of the disease is recommended when there is a gradual onset of clinical signs or when clinical signs are limited to pain and/or a mildly wobbly gait. Conservative management involves pain relievers, muscle relaxants, and anti-inflammatory medication.

Surgery is recommended when there are repeated episodes of neck pain, when neck pain is severe, when there are severe nervous system deficits, or when the dog has not responded to conservative treatment. It is important to monitor a dog’s ability to urinate and defecate normally.

With or without surgery, physiotherapy is a critical part of healing and recovery. Physiotherapy may include acupuncture, therapeutic laser, massage, hydrotherapy, and passive range of motion to prevent loss of muscle mass.

What happens after treatment?

All affected dogs should be fitted with a harness instead of a neck collar, and they should have their activity limited, at least early in the recovery period. Strict rest is required in the first 3–6 weeks following a disc protrusion or rupture, with or without surgery. Your veterinarian will prescribe increasing levels of activity as healing progresses.

If surgery is needed, the goal is to remove disc material from the space surrounding the spinal cord. This surgery usually provides immediate pain relief and long-term restoration of nervous system function. Several surgical approaches can be used to access the spine. Given the delicate nature of this type of surgery, it is generally done by a specialist surgeon or neurologist.

Is long-term follow-up required?

Initially, veterinary rechecks will be frequent until clinical signs are resolved. Getting the dog to a healthy weight, if needed, and maintaining that weight will help the dog recover more quickly and maintain an active lifestyle. Unfortunately, there is no way to prevent intervertebral disc disease.

Long-term complications are uncommon but may include persistent neck pain or a deterioration in standing and/or walking. For most patients, the long-term outlook is favorable. Dogs with chronic disc disease or with multiple disc involvement are likely to have a recurrence of clinical signs. Dogs with cervical disc disease should always be walked using a harness rather than with a leash attached to a collar.