Disc Disease

1) Cervical Disc Disease
by Dr. Paul Newman

Your veterinarian suspects that your pet may be experiencing a slipped disc in the neck causing pain or paralysis. The cervical spine (neck) is made up of bony segments called vertebrae. The discs are located between the vertebrae and serve as shock absorbers for the spinal column. The normal disc is a firm, jelly-like structure.

When a disc becomes diseased, either through a gradual degeneration (birth defect) or injury, the weakened structure starts to slip out of place. It may also completely rupture and the subsequent pressure on the spinal cord and nerves causes pain, incoordination, weakness or paralysis. Some patients will appear to have a limp on a front leg called a “root signature” as the disc is pressing on the nerve root and causing shooting pain down the leg.

Medical treatment for this problem may relieve pain and inflammation, but surgery is often necessary to relieve pressure on the nerves and spinal cord to prevent further damage or recurrence.

Physical examination, radiographs, myelogram, CAT scan or an MRI will help your veterinarian determine the best course of treatment for your pet. If medical management is recommended, it may include any or all of the following:

  • Absolute rest or confinement at home with medication.
  • Confinement in the hospital while on strong medication.
  • Chiropractic manipulation of the spine.
  • Acupuncture therapy.
  • Weight loss.

If your pet’s only symptom is pain, we usually recommend medical treatment for 1-2 weeks before considering surgery. If the pain worsens or recurs often, then surgery is necessary. There are two different surgical options, fenestration and slot decompression. We usually do a fenestration in patients with just pain and decompression for pets with paralysis or persistent pain after fenestration. Neither one of these surgeries is 100% successful and the biggest complication we see with either surgery is the need for a second surgery.

If surgery is being contemplated, especially decompressive surgery, it is imperative to confirm the diagnosis or determine exactly which disc is causing the problem. Since discs are made up of mostly water, they do not show up on regular radiographs unless they are prematurely calcified. Otherwise, special imaging tests are necessary including myelograms (contrast injected into the spinal canal to outline the spinal cord) with radiographs or with a CAT scan; or an MRI (the best imaging modality for disc disease.

Comparison Between Fenestration and Vertebral Slotting

FENSTRATION

SLOT

Technically

Easy

Difficult

Accurate Identification Of Disc Involved

Not required

Required (via MRI or myelogram w/CAT scan)

Special Equipment Required

No

Yes

Potential To Worsen Condition

Unlikely

Possible

Removal Of Disc Material From Spinal Canal

No

Yes

Cost

Moderate

High

Resolution Of Neck Pain

Slow in many dogs (1-8 weeks)

Usually within a few days

2) Non-surgical Home care of disc patients
by Dr. Paul Newman

When a dog starts to show mild signs of pain indicative of intervertebral disk disease but is still ambulatory, restricted activity in a cage is indicated. Allowing nature time to heal the tear in the annulus fibrosus may be all that is necessary. If corticosteroids are simultaneously administered, restricted activity is an absolute must. Corticosteroids will mask the pain the body is using to tell your dog to “slow down.” If the nucleus pulposus has not herniated but significant weakening of the annulus fibrosus exists, one good jump off the couch is all it may take for your dog to become hopelessly paralyzed from irreversible spinal cord injury. The absolute necessity of cage rest in these animals cannot be overstressed. Failure to do so often contributes to disk herniation. Such a dog can never be hurt by too much cage rest, but certainly devastating results can occur if too little cage rest is used.

When disk disease causes motor deficits, a great deal of damage can be done to the feet and legs if your dog is not restricted from dragging across rough or had surfaces. When you can not directly supervise your dog’s activity, they should be put in its well padded cage to avoid further injury. When outside, protective foot coverings are a great help. Once sores are allowed to form they are very difficult to clear up; preventing them is far better. You should carry your pet outside twice daily to eliminate but keep them on a short leash to prevent any running, jumping or playing. Stairs are absolutely not allowed, even one or two small stairs to the outside.

Disk herniation not only damages descending motor tracts to the legs, but also those that are involved in normal urination and defecation. Consequently, a number of dogs will require special attention to these functions. It is very common to see urinary incontinence following disk herniation. Care must be taken to see that the bladder is emptied properly several times a day to avoid urinary tract infection. This may require regular (4 to 5 times per day) manual expression of urine from the bladder. Fecal incontinence is less of a problem but still must be watched and treated if necessary with stool softeners.

Especially in paralyzed patients, regular cleaning of your dog and their bedding is imperative to avoid urine scalding and infection of the skin. Ointments to provide a water barrier are very useful. Additionally, a well padded bed must be provided to avoid the development of bed sores (decubital ulcers). Once the skin lesions break open, massive systemic infection may result which can be life threatening. It is far simpler to prevent these problems from arising rather than treat them after the fact.

Two weeks of strict confinement is the bare minimum for most pets. If your pet is out of pain and walking well, you should slowly start increasing their activity to include short periods out of the crate under supervision to prevent running, jumping and playing. Each week you can increase the amount of activity to include short ten minute walks. If, at any time, your pet worsens, you must go back to total confinement.