Lumbrosacral instability in dogs is known by names including canine equida syndrome and lumbrosacral stenosis. While it generally affects older large-breed dogs, some small and midsize canines are born with the disorder, showing symptoms at a young age. The congenital form is easier to diagnose than the late-onset type of this degenerative condition.
Lumbrosacral instability occurs when nerves -- the cauda equina -- in the lower part of the spinal cord compress. In dogs not born with the condition, it can result from bone spur development, intervertebral disc disease, cancer, osteoarthritis, degenerative spinal cord narrowing or trauma. Whether the condition is congenital or degenerative, the spinal cord swells. Dogs suffering from lumbrosacral stenosis are in pain.
You might notice that your dog can no longer easily get into the car or climb stairs. Your once-active dog might not want to run and play, showing little enthusiasm for physical activity. He might show obvious lameness while walking, as well as rising from a sitting or prone position. His hind legs might go out from under him or appear unstable. He might not wag his tail much. Some dogs lose control of their bowels and bladder.
Symptoms of lumbrosacral instability mimic other degenerative canine back and neurological problems, such as hip dysplasia, so your vet will need to conduct extensive testing to determine the cause of your dog's issues. Besides general blood tests and urinalysis, your vet will perform X-rays, magnetic resonance imaging and computed tomographic scans to make a diagnosis. Once the dog's diagnosed, she might refer you to a veterinary neurologist for further treatment.
If your dog is mildly affected, your vet might opt for conservative treatment. She'll prescribe analgesics for pain relief or nonsteroidal anti-inflammatories to relieve pain and inflammation. Your dog must rest, with very limited exercise. Severely affected dogs usually require surgery, consisting of a laminectomy to remove disk material and reduce nerve compression. The surgery might also include fusing the last lumbar vertebrae to the sacrum, according to the American College of Veterinary Internal Medicine. It will take your dog a month or more to recuperate, but he should eventually return to his normal activities within several months.