INTERVERTEBRAL DISC DISEASE (IVDD) IN DOGS

The degeneration of the intervertebral discs, leading to bulging or rupturing of the discs, causes the compression of the spinal cord and therefore Intervertebral Disk Disease (IVDD). The normal function of the intervertebral discs is to be a cushion, absorb shock, and provide for spinal flexure. When the discs are damaged, they can compress nerves and lead to pain, muscle weakness, or even paralysis.

IVDD is the most common dog neurologic disease and has been found predominantly in Chondrodystrophic breeds such as Dachshund, Beagle, Shih-Tzu, etc. Depending upon the extent of damage to the discs, symptoms can range from mild back pain to total paralysis.

Causes

Degenerative changes in the intervertebral discs lead to IVDD; this can result from genetic factors, aging, trauma, etc. Small breeds of dogs typically have their intervertebral discs start to harden and decrease in flexibility much earlier than larger breeds. Therefore, if an injury occurs during play or a sudden jump, there is a high likelihood that the disks will rupture or herniate.

Larger breeds may also experience IVDD, but generally this occurs after years of slow deterioration of the spine. Obesity increases the chance of IVDD because it adds additional weight-bearing stress on the spine and related structural elements.

Symptoms

Early Signs

• Reluctance to jump or climb stairs
• Mild back or neck pain
• Stiffness or reduced activity
• Unusual posture or arched back

Progressive Signs

• Weakness in hind limbs or front limbs
• Difficulty walking or a wobbling gait
• Loss of coordination
• Crying out in pain when moving or touched

Severe Signs

• Complete inability to walk
• Loss of bladder or bowel control
• Paralysis of limbs
• Extreme pain or sudden collapse

The beginning of signs may start right away or gradually, based upon the degree of damage to the discs.

Risk Factors

If left untreated, IVDD will potentially hurt your dog’s quality of life and be life altering. Pressure on the spinal cord that is severe enough to cause damage to nerves can occur within hours to days after the initial trauma to the spine; it is best to relieve pressure immediately.

In some severe cases, the lack of treatment could result in permanent paralysis. As time passes with continued compression of the spinal cord, there is less blood flowing to the spinal cord and an increased risk of long term loss of function.

Chronic pain can also develop from prolonged periods of immobility, which can affect your dog’s quality of life and ability to move.

Complications, including atrophy of muscles, pressure sores, urinary tract infections, and others, may arise as a direct consequence of limited mobility.

Diagnosis

A veterinarian uses a combination of a physical or neurological exam and imaging studies to diagnose IVDD.

Using specific criteria (including reflexes, reaction to pain, coordination), veterinarians will identify areas of spinal damage. Once identified, the veterinarian can use imaging studies to confirm the diagnosis.

Diagnostic Tools

• X-rays to examine spinal alignment and rule out other causes of spinal issues.
• MRI (most accurate diagnostic tool) for visualizing compression of the spinal cord and damage to the intervertebral disc.
• CT scan for detailed evaluation of bones and soft tissues.
• Myelography if an MRI is unavailable.

Treatment

The treatment of this condition will depend upon how severe it has become and the degree to which the spinal cord has been compressed.

Conservative Management

Many mild cases can be treated without surgery through bed rest and use of medications. These can include:

• Cage rest for an extended period
• Pain-relieving medications
• Anti-inflammatory medications
• Muscle relaxing medications

Bed rest is mandatory in order to avoid additional disc damage.

Surgical Treatment

In cases of severe IVDD where there is either paralysis or loss of deep pain sensation, surgical treatment is usually required. The purpose of surgery would be to remove the disc tissue that is compressing the spinal cord and to provide stability to the spine.

Surgery provides the highest likelihood of recovery in severe cases as long as it is done quickly.

Rehabilitation

Following your dogs treatment, some veterinarians recommend physical rehabilitation to enhance muscle strength and mobility. There are many forms of rehabilitation, including controlled exercises, hydrotherapy and physiotherapy.

Prevention

While IVDD is sometimes unpreventable due to genetic factors, you can reduce the risk by providing your dog with good care. Some ways to do this are

• Having your dog at a healthy body weight
• Using ramps or steps may help reduce repeated jumping in high risk dogs
• Providing regular low impact exercise
• Avoiding rough play and abrupt twisting motions
• Scheduling early veterinarian visits should you notice your dog exhibiting stiffness.