INTERVERTEBRAL DISC DISEASE

Conditions or forces can cause the invertebral discs (the cushion which lies between the bones of the spine) to swell or rupture. This can result in two types of damage, concussion and compression. The extent of damages caused can be determined by:

• Type of force
• Amount of force endured by the spinal cord
• Time force was applied for

Minor spinal cord damage can result in your pet losing coordination and walking in such a way that resembles a drunken sailor. More significant damage can lead to loss of mobility and inability to voluntarily move their legs. Severe damage can result in complete loss ability to perceive pain. Recovery is not always possible. It is dependent on how long the sensation of pain has been lost for.

Chondrodystrophoid breed dogs such as Dachshunds, Beagles and Pekinese are prone to developing this condition. These breeds account for majority of the invertebral disc disease cases with Dachshunds having the highest percentage of cases. Signs are often seen between the ages of 3 to 6 years. However, X-rays can identify disc calcification anything from 2 years of age. Disc ruptures are often thoracolumbar (in the back region) and seldomly cervical (neck region).

There are different degrees of pain associated with disc rupture. However, nerve damage development and progression usually has obvious signs with a predictable pattern.

1. Visible neck or back pain often accompanied with the unwillingness to walk.
2. Wobbly hind end with the pet’s hind feet crossing over as they walk.
3. Loss of all hind leg motor functionality accompanied by the inability to urinate.
4. Loss of pain perception which indicates severe cord injury.

Disc ruptures are classified in regions. These groups are named:

• (C1-C5)Cervical vertebral 1-5
• (C6-T2)Cervical vertebrae 6 to thoracic vertebral 2
• (T3-L3)Thoracic vertebrae 3 through lumbar vertebrae 3
• (L4-S3) Lumbar vertebrae 4 to sacrum

The grouping is known as neurolocalization and the purpose of it is to help the veterinary surgeon decide which tests and surgeries will be appropriate for each case. Invertebral disc rupture is a surgical emergency and prognosis depends on the functionality of the pet when evaluated.

Your veterinarian may suggest a health screening followed by some of the following imaging techniques: • Blood work such as: serum chemistry, complete blood count and urinalysis.

• X-rays
• Myelogram, a type of X-ray where dye is injected around spinal cord in order to see any compression.
• A CT scan in place of or following the myelogram.
• A MRI instead or in addition to a CT scan.
• Spinal tap during imaging.

Patients who have only recently begun episodes may benefit from conservative treatment with confinement, cage rest and pain medication. Consulting with your veterinarian may lead to referral to a veterinary surgeon for more options.

There is a range of procedures and approaches that exist and can be used depending on the surgeon and location of the disc. The veterinary surgeon will make the choice of procedure according to their experience and preference. The most commonly recommended procedure is removal of the bone over the spinal canal for surgical decompression of the spine.

Surgery:

The ruptured disk material (compressing the spinal cord) is usually removed by a hemilaminectomy. The surgery involves creating a hole on the side of the vertebrae where the offending disk is. This procedure may also assist with relieving some of the pressure from the spinal cord.

“Fenestration” of invertebral disks is often performed when it is the mid-back being operated on. This procedure involves the creation of an incision that allows the jelly-like substance to leak out. It also decreases the risk of future spinal cord compression and disk rupture.

Prognosis:

Sensation in the hind limbs before and after surgery indicates that your pet is likely to regain the ability to walk again. Some pets will recover faster after surgery than others.

Most pets are able to walk again between 3 to 6 weeks after surgery. In some cases there is no neurological status improvement in the first month and then a rapid improvement follows. The spinal cord will continue to heal for 6 to 9 months after surgery. This means, after 6 to 9 months has passed, your pet’s neurological status will no longer improve.

It is possible for a pet to experience some hind limb weakness, but will still be able to function well enough.

If your dog has no deep pain sensation, it is possible that they may never walk again. The surgery needs o be done within 12 hours after the sensation in the hind legs is lost in order to give your dog a 50-75% chance of walking again.

If circumstances do not allow your pet to regain their ability to walk, you can purchase a K-9 cart to attach to your dog. This is a pet’s version of a wheelchair. It is a harness which is strapped around the pet, the pet can then move around using their front legs.

Your pet is usually discharged about 3 to 7 days after surgery. An appointment will be created for a check-up where stitches or staples will be removed. Pain medication can be administered by the owner.

Postoperative recovery may include:

• Bladder expression 3 or 4 times daily
• Regaining muscle flexibility and strength through physical rehabilitation
• A restriction of physical exercise for 4 weeks after surgery Some lifestyle changes may be appropriate. A body harness should be used rather than a neck leads and your pet should be restricted from jumping off of furniture. They may also lose weight.

Potential complications can include:

• After a myelogram procedure, seizures can take place within the first 24 hours.
• Infections.
• Another disc herniated in the future.
• Inability to walk normally.

Prognosis is dependent on the degree and location of injury. Dogs who are able to walk and suffer a disk rupture, often are able to continue walking after the procedure. Pets who lose pain sensation, may never walk again.

Leaving the disease untreated can also cause the pet to never walk again. The dog will then also be at risk of chronic urinary tract infections or urine scald. In addition to this, they may never regain their personality and can develop wounds associated with constant bed rest.