Thoracolumbar Intervertebral Disc Disease

Dachshund

Who is usually affected?
-Younger to middle aged dogs
-Commonly seen in Dachshunds, Cocker Spaniels, Pekingese, Shih Tzus, Lhasa Apsos, Beagles, Miniature Poodles, and Basset Hounds

What is happening?
-Cartilage discs that are normally positioned between the bones of the spinal column in the middle to lower back (thoracolumbar vertebrae), break down and rupture (herniate) into the spinal canal
-Disc material places pressure on the spinal cord or nerve roots of the back
-Disc pressure causes swelling, pain, and often dysfunction of nerves

Myelographic appearance of a thoracic intervertebral disc herniation at T12-13, lateral view Click to enlarge

Clinical signs you might notice in your pet
-Reluctance to jump, or walk up and down stairs
-A noticeable decrease in activity and energy
-Obvious pain when picked-up or pressure placed on back, often indicated by whimpering or crying
-Weakness and/or incoordination of the hind legs causing an awkward walk
-In severe cases, inability to stand or walk

*SEVERE PAIN OR LIMB WEAKNESS IS AN EMERGENCY CONDITION. TAKE YOUR ANIMAL IMMEDIATELY TO THE CLOSEST A VETERINARIAN EMERGENCY CLINIC*

Diagnosis
-Careful neurological examination to assess the patient for pain and loss of nerve function
-X-rays are used to examine the bones of the spine, this is usually combined with a special x-ray study using a contrast liquid (myelogram) to examine the spinal cord
-In some cases, CT or MRI scanning may be appropriate

Myelographic appearance of a thoracic intervertebral disc herniation at T12-13, VD view Click to enlarge

Surgical treatment
-Removal of a limited portion of the bony spine (hemilaminectomy, dorsal laminectomy, or pediculectomy) to access the spinal canal and decrease pressure on the spinal cord
-Removal of the ruptured disc material from the spinal canal
-Partial removal of adjacent discs (fenestration) may be performed concurrently

Special postoperative care
-Patient activity is limited to short walks for 4-8 weeks
-Assistance with urination may be necessary in some cases, this usually involves the application of pressure to the abdomen to aid with bladder emptying
-Physical therapy will likely be prescribed for pets that are unable to move their legs appropriately

Expected results with surgery
-Back pain relief
-A return to normal walking is very likely (90%) if the patient was able to feel his/her legs prior to surgery
-Maximal recovery may take weeks to months to occur because nervous tissue heals slowly in comparison to most other tissues in the body