At the Animal Clinic at Thorndale, we all love to see happy wagging tails. However, there are a group of our patients for whom tail wagging is painful or just not possible. One of the causes is lumbosacral stenosis.
This is a disease that occurs at the lumbosacral junction. The term “lumbo” refers to the lumbar vertebrae. These are the bones in the lower part of the spinal column. The term “sacral” refers to the sacrum, which is the part of the spine that joins the lumbar spine and the pelvis. Changes that occur in the vertebrae, supporting ligaments or adjacent disks can all contribute to this pathologic narrowing of the spinal cord canal.
Prevalence
This disorder is seen more commonly in adult dogs of large breeds. Males may be affected more often than females. German Shepherd dogs appear predisposed to the condition.
Causes/Transmission
Lumbosacral stenosis occurs from one or more types of changes at this vertebral junction: a congenital malformation, proliferation of ligaments which support the joint, instability at the joint, or compression from a protruding disk.
In some dogs, abnormalities in the structure of the vertebrae may be present at birth, but problems do not become apparent for a number of years.
Clinical Signs
When instability exists along the spine, abnormal movement occurs. The onset of signs is usually gradual, with continuous progression and worsening over time. Early signs can include pain and lameness. Gradually, with continued compression of the spinal cord, affected dogs lose control of the back legs, tail, urinary bladder and bowel. Often these dogs present as unable to wag their tail and an ataxic (wobbly) gait in their back legs.
Diagnosis
Radiographs (x-rays) will generally reveal arthritic changes at the lumbosacral junction. However, this is common in many dogs and may not cause any clinical signs. As such, x-rays may offer only indirect evidence of the disorder.
If the clinical signs are correct and the initial radiographs are suggestive of lumbosacral stenosis, a special radiographic study, called a epidurogram, may be performed. More commonly, MRI and CT scans are used to visualize the spinal cord compression and boney changes, respectively. In some cases, a presumptive diagnosis be made based on the dog’s breed, age, clinical signs and progression of disease.
Treatment
If your dog is overweight, weight reduction will be an important part of the treatment. Any disorder of the back is aggravated by excessive body weight.
Strict rest is also an important part of treatment for any back problem. Cage rest is preferable, but confinement in a small fenced run or small room is acceptable.
Anti-inflammatory drugs and pain relievers will often give temporary relief.
Although infection in the disk is not a common cause, it should be treated with appropriate antibiotics if it is present. An infection of this nature usually requires 4-8 weeks of therapy.
Surgery can be performed and is helpful in relieving compression on the spinal cord for years to come. In some cases, surgery is not indicated or desirable. This is decided on an individual basis.
Prognosis
The prognosis is variable depending upon the severity of the clinical signs and response to treatment. Dogs who have loss of bladder and bowel control have a more guarded prognosis for return to normal function.