Lumbosacral Spinal Disease

Who is usually affected?
-Older, large breed dogs
-Younger to middle aged German Shepherd dogs

What is happening?
-Chronic strain to the cartilage disc that is normally positioned between the bones of the spinal column in the lower back (lumbosacral vertebrae) results in a bulging of the disc into the spinal canal
-Disc material places pressure on the nerves of the lower back (cauda equina)
-Disc pressure causes inflammation, pain, and sometimes dysfunction of nerves
-Similar problems can arise from bony remodeling or ligamentous enlargement in the region

Clinical signs you might notice in your pet
-Reluctance to jump, or walk up and down stairs
-Obvious pain in the lower back
-Weakness and/or incoordination of the hind legs causing an awkward walk
-In severe cases, loss of bladder or bowel control may occur

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

X-ray demonstrating a collapsed lumbosacral inververtebral disc space and needle placement to administer contrast agent for an epidurogram Click to enlarge

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 special x-ray studies using a contrast liquid to examine the spinal cord (myelogram) and nerves (epidurogram)
-In some cases, CT or MRI scanning may be appropriate

Surgical treatment
- Removal of a limited portion of the bony spine (dorsal laminectomy and/or foramenotomy) to access the spinal canal and decrease pressure on the nerves
-Removal of the bulging disc material, excessive bone, and/or enlarged ligaments from the spinal canal
-In some cases, fusion of the vertebrae is necessary to prevent continued problems

Computed tomography (CT) image of lumbosacral disc herniation Click to enlarge

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
-Lower back pain relief
-Improved walking/neurological function will occur in most patients, but some may experience only a stoppage of any decline in neurological function
-Bladder and bowel control are not likely to return to normal if incontinence was present for some time 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