What is degenerative lumbosacral stenosis?

Degenerative lumbosacral stenosis (DLSS) is a multifactorial disorder. It occurs when bone and soft tissue abnormalities impose on the nerve roots of the cauda equina (a group of nerves and nerve roots). Vertebral canal compression can be caused by a combination of;

  • Hansen type-II intervertebral disk protrusion,
  • Ligamentous and articular process hypertrophy,
  • Osteophyte formation,
  • and vertebral misalignment.

It also leads to radiculopathy, commonly referred to as a pinched nerve, which refers to a set of conditions in which one or more nerves are affected and do not work correctly (a neuropathy). This can result in pain (radicular pain), weakness, numbness, or difficulty controlling specific muscles.

Ho do I know if my dog has degenerative lumbosacral stenosis?

Degenerative lumbosacral stenosis generally affects mature large-breed dogs, in particular German Shepherds. Clinical signs are variable and include;

  • Signs of pain in the lumbosacral region without neurologic deficits,
  • Unilateral or bilateral pelvic limb lameness,
  • Paraparesis,
  • Difficulty jumping or climbing stairs,
  • Abnormal tail carriage,
  • and urinary and faecal incontinence.

How is degenerative lumbosacral stenosis diagnosed?

Because these signs also occur with diseases of the coxo-femoral joint or low lumbar vertebrae, signs of pain elicited on the extension of the hip are not specific for lumbosacral disease.

Pain on rotation or abduction of the hip (without extension or lumbosacral stenosis pressure) is more specific for coxo-femoral joint disease than for lumbosacral stenosis disease. Therefore, pain induced by hip extension without pain on abduction or rotation of the hip is more supportive of low back pain.

Given that many large dogs have both hip dysplasia and degenerative lumbosacral stenosis, the clinician has to determine the most clinically relevant condition in order to appropriately treat each individual.

The tail jack test (where you lift the tail until you encounter resistance) can be ambiguous as it evokes a response in many randomly tested normal dogs.

Unfortunately, there is no consensus of opinion on what constitutes an advanced imaging diagnosis of degenerative lumbosacral stenosis and validation of imaging findings is hampered by lack of a defined disease definition. When attempting to predict the outcome for any dog affected with degenerative lumbosacral stenosis, the results of imaging may be less important than the clinical signs and surgical factors.

How is degenerative lumbosacral stenosis treated?

Medical management includes epidural infiltration, non-steroidal anti-inflammatory drugs, rest, physiotherapy and acupuncture.

There is currently no consensus on treatment selection for dogs with degenerative lumbosacral stenosis. Even with human medicine, current evidence comparing surgical versus non‐surgical care for lumbar spinal stenosis is of low quality. Nevertheless, given the high rates of side effects associated with surgery, clinicians should be cautious when proposing surgery for degenerative lumbosacral stenosis, and patients should be properly informed about the risks.