Canine Intervertebral Disk Disease

Intervertebral Disk Disease is a neurologic problem affecting both humans and canines. The spine is made up of bone segments called vertebrae. The vertebrae are separated by intervertebral disks. Each disk is made up of a fibrous outer zone called the annulus fibrosis and a soft jelly-like inner section called the nucleus pulposus. Disk disease occurs when there is a defect in the annulus fibrosis, which allows the nucleus pulposus to bulge or rupture into the space normally occupied by the spinal cord. Canine intervertebral disk disease occurs either through gradual degeneration of the disk or as the result of acute injury or trauma. Canine intervertebral disk disease is most common in Dachshunds but may be seen in almost any breed.

Disk disease most commonly affects the disks in the thoracolumbar region or the cervical region of the spine. Clinical signs of cervical disk disease include neck pain and a hunchbacked posture that resembles a turtle. Dogs that have cervical disk disease are often reluctant to lower their heads to eat and drink and may cry out in pain when the neck is manipulated or touched. If there is sufficient disk material involved, there may be proprioceptive, sensory and motor (limb placement, pain perception and gait) deficits, although this is rare. Clinical signs of thoracolumbar disk herniation are unfortunately more profound than in the cervical area. This is due to the relative lack of space in the spinal canal. With almost no extra space, the spinal cord can be severely compromised with smaller bulges and herniations. These dogs are reluctant to move and may adopt a hunchbacked posture. They often cry out when picked up. If more severely compromised, the dog may walk with a wobbly gait and drag the hind toes. Further compromise leads to hind limb paralysis and loss of pain sensation in the hind toes. Disease at this stage is to be considered a medical emergency and immediate surgical intervention is necessary.

Diagnosis of canine intervertebral disk disease is based upon the history of the problem, clinical signs, the results of neurologic tests and abnormalities seen on radiographs. Due to the painful nature of the condition and to the complexity of the spine, sedation is often necessary to obtain quality radiographs.  In addition to radiographs, if surgery to an option, a CT or MRI Scan or a procedure known as a myelogram may need to be performed to identify the offending disk space.

Treatment of the more severe forms of canine intervertebral disk disease must include immediate surgery. The effectiveness of surgery decreases dramatically the longer signs persist prior to surgery. The purpose of surgery is to decrease pressure on the spinal cord. This is achieved by removing part of the vertebral body and by removing the ruptured disk material. Chronic moderate disk disease can also be effectively treated with surgery. While steroids and other anti-inflammatory drugs can lessen symptoms, only removal of the disk material that is putting pressure on the spinal cord will permanently relieve symptoms.

Mild acute disk disease is treated using anti-inflammatory drugs, pain medications and strict cage rest. We may also recommend that muscle relaxants be used. In all cases, dogs with intervertebral disk disease require special treatment. Dogs with disk disease should not be allowed to walk up or down steps. They should not be allowed to climb or jump off objects like furniture or beds.