Spine Diseases In Dogs
What is Cauda Equina Syndrome?
Cauda Equina Syndrome (CES) is caused by compression of the nerve roots passing from the lower back toward the tail at the level of the lumbosacral junction. The most common cause of cauda equina syndrome is narrowing of the vertebral canal at the level of the lumbosacral joint (called lumbosacral stenosis).
Lumbosacral stenosis is most commonly caused by degenerative changes to the intervertebral disc, arthritis of the joints, and abnormal proliferation of the ligaments. Dogs with abnormal shape to their last lumbar or sacral vertebrae and german shepherd dogs are predisposed to developing lumbosacral stenosis. Neoplasia (cancer) and infection at the level of the lumbosacral disc (discospondylitis) may also cause signs of cauda equina syndrome.
What are the symptoms of Cauda Equina Syndrome?
The most common neurologic sign associated with CES is pain in the lower back. Signs of pain may include decreased willingness to jump up and climb up stairs, low tail carriage or reduced tail wagging, difficulty posturing to defecate, and whimpering/ crying if the lower back is touched. In some cases dogs will have a weakness or lameness in one or both hind limbs, which occurs secondary to compression of the nerve root supplying the sciatic nerve as it exits at the lumbosacral joint. If the compression of the nerve root causes significant pain, dogs may hold up a limb after exercise or cry out. Severe compression of the nerve roots can lead to fecal and urinary incontinence which is irreversible in most cases.
How do you diagnose Cauda Equina Syndrome?
The first step in diagnosing Cauda Equina Syndrome is a neurologic examination. The doctor will observe the dog’s gait for any lameness and/or stiffness. A physical examination will include palpation over the spine to determine the site where the dog is most painful. Manipulation of the hips and tail will elicit pain response in most dogs suffering from cauda equina. The doctor will also test reflexes, proprioception (foot placement), and anal tone. Radiographs are taken to look for abnormal shape of the lumbosacral joint, spinal arthritis at the lumbosacral joint, infection of the disc space, or tumors. An MRI (magnetic resonance image) is the preferred imaging test to examine the nerve roots. In some cases CT (computed tomography) is used to better visualize the bone in dogs with lumbosacral disease.
How do you treat Cauda Equina Syndrome?
The treatment directly correlates to the degree of the symptoms. Dogs who are exhibiting mild pain and have never had an episode of back pain before are usually treated with strict rest and pain medications. In cases where the dog is not responding to conservative, medical therapy or exhibiting neurologic symptoms, surgical intervention is necessary. The procedure is called a dorsal laminectomy and involves removing the ‘roof’ of the spinal canal to release the entrapped nerve roots and remove the associated ruptured intervertebral disc if present. If necessary, a foraminotomy is performed to open the nerve root canals and relieve the entrapped nerve roots. In some cases if there is significant instability at the lumbosacral joint, the joint is surgically stabilized with pins and bone cement.
What is the post-operative prognosis?
Prognosis is very good in dogs with mild neurologic signs (i.e. pain only, mild weakness). Dogs with severe nerve root compression and subsequent urinary or fecal incontinence have a very poor prognosis, and the majority of dogs never become continent again even with surgery. Surgery can work to alleviate the pain in these dogs, however.
Many dogs with lumbosacral disease have other back problems (i.e. chronic intervertebral disc disease) and hip or other orthopedic disease, which can affect their recovery after surgery. Recovery is also slower in overweight dogs, and obese patients must be put on a strict diet to reduce their weight.
Strict cage rest is critical to a good surgical recovery. Specific complications that can occur after surgery include formation of a fluid pocket or scar tissue that compresses the nerve roots or fracture of the bones at the surgery site. Dogs who are overly active after surgery are much more likely to develop complications.
Lumbosacral Spondylosis in Dogs
Lumbosacral spondylosis is a degenerative arthritic condition of a dog’s spine. It usually develops as a dog moves into his later years, and it affects his mobility. Let’s look at the symptoms of lumbosacral spondylosis and what you and your veterinarian can do to help your dog feel better if he has this condition.
Lumbosacral Spondylosis Symptoms
Symptoms of lumbosacral spondylosis can range from asymptomatic (showing no symptoms) to severe disability. Common symptoms include:
The exact cause of lumbosacral spondylosis is unknown, although genetics, trauma or environmental factors may play roles in its development.
Lumbosacral spondylosis affects the lower part of the dog’s spine and should not be confused with cervical spondylosis, which affects a dog’s upper spine, or thoracic spondylosis that affects the middle of a dog’s spine. It is common in large breed dogs, especially the German shepherd, in their later years. Dogs are most likely to show symptoms as the disease first develops, but they seem to adjust to the disease after an initial adjustment period.
Diagnosing and Treating Lumbosacral Spondylosis
Your veterinarian may use a variety of tests to diagnose lumbosacral spondylosis in your dog. These may include a physical examination, laboratory tests and x-rays. He or she may also request a myelogram (a test of spinal compression), a force plate analysis (to determine weight tolerance) and joint fluid analysis (an examination of fluid from your dog’s joints to determine whether his problems are caused by a degenerative or infectious disease).
After a diagnosis has been made, your veterinarian will formulate a treatment plan. Depending on the severity of your dog’s symptoms, treatment may include:
In severe cases, surgery may be required to relieve your dog’s pain. In most cases, your veterinarian will remove bone spurs that have formed on your dog’s spine and irritate the nerves in your dog’s back legs. Follow-up care, including physical therapy, is usually needed to help your dog make a full recovery in about six months.
Additional Steps That Can Help Your Dog
Discuss your dog’s treatment plan with your veterinarian to see if additional steps can be taken to further ease your dog’s discomfort. If he’s overweight, a weight reduction and management plan may need to be part of your dog’s treatment plan because additional weight is detrimental to your dog’s overall health, and the extra weight isn’t helping his lumbosacral spondylosis, either.
Implementing a daily exercise plan tailored to your dog’s situation can help manage his condition. Walking is one recommended exercise, but swimming or other water therapy can also help less-mobile dogs achieve their exercise goals. Exercise also helps your pet maintain a healthy weight.
Heat therapy may be another useful part of your dog’s overall treatment plan. He may benefit from moist heat, such as the use of water bottles or warm towels wrapped around his joints to help ease his discomfort. Some dogs may also find pain relief from regular gentle massages, which can help stimulate blood flow and loosen tight muscles.