lumbosacral stenosis and spine disease (LS)
What is Lumbosacral Disease?
Lumbosacral disease is also known as cauda equina syndrome. The lower spine is the area that is most affected. The average age of onset is 7 years, and the condition is seen most often in large breed dogs, particularly the German Shepherd. Lumbosacral disease can be acquired or congenital. Back pain evolves to a compression of the nerves, progressing to loss of neurological function.
This condition is most often of a degenerative nature; however, many canines can improve with medical management (medication and change in activity) while others will require surgical intervention. Early diagnosis and treatment is beneficial and may prevent painful progression of the condition.
Lumbosacral disease is a condition that adversely impacts the nerves that are connected to a dog’s spinal cord, resulting in disease of the L7-S1 junction. Lumbosacral disease will result in changes to the intervertebral discs and the spacing found there. Back pain and lack of mobility in canines must always be evaluated by a veterinarian. Ageing may result in dehydration and degeneration of this disc which may then bulge (protrude) and compress or ‘trap’ regional nerves. The resultant narrowing of the canal in the spine (the vertebral canal) or the exit holes between the bones (the vertebral foramen) is referred to as stenosis. The underlying cause of the disc degeneration and bulging is unclear, although in some dogs it is associated with instability of the bones of the spine.
Symptoms of Lumbosacral Disease in Dogs
Back pain is the key clinical feature of the disease. Typically, affected animals are reluctant to jump and climb, and they may have difficulty rising from a lying position. Groaning or spontaneous yelping may be a feature. Less common signs include hind limb lameness (due to spinal nerve compression), incontinence and reduced tail movement.
When the spine is abnormally unstable, movement can be difficult and painful. Other signs of the disease include:
- Worn nails
- Limited movement
- Difficulty squatting
- Low tail position
- Reluctance to wag the tail
- Licking of the genital area
- Self mutilation
- Fecal incontinence
- Urinary incontinence
- Reluctance to participate in activity
Causes of Lumbosacral Disease in Dogs
- May present as arthritis or hip dysplasia which must be ruled out
- Ligaments may thicken
- Disc protrusion or herniation may be present
- Trauma to the spine can be a factor
- Male canines are more affected
- Working dogs are most prone
- Neoplasia can cause the disease
- Discospondylitis may be concurrent
Diagnosis of Lumbosacral Disease in Dogs
The veterinarian may commence the diagnosis with the intention of ruling out conditions that may present the same such as hip dysplasia, muscle injury, cancer, or a fracture of the spine. Imaging tools such as an x-ray can provide needed information. Along with x-rays, details can be fine tuned with the use of a CT scan and MRI.
A physical examination may be considered; however, it depends on the amount of pain your dog is experiencing. Lack of reflexes and muscle atrophy are just two of the clinical signs that may be seen. In many cases, the physical palpation of the limbs is avoided in order to not cause your pet more pain.
Treatment of Lumbosacral Stenosis in Dogs
As in people with back pain associated with a ‘slipped disc’ in the lower back, the majority of dogs and cats with lumbosacral stenosis can be successfully managed without the need for surgery. It is often necessary to modify exercise with avoidance of strenuous activities that involve jumping, climbing, twisting and turning. Dogs should initially be walked on a lead (short distances frequently) and exercise should be gradually increased over a number of weeks. Overweight patients should be placed on a calorie restricted diet. The majority of affected animals will benefit from receiving pain killing medications. Anti-inflammatory agents, neuropathic drugs and muscle relaxants may all be beneficial.
Lumbosacral stenosis may also be managed by injecting a long-acting steroid (cortisone) around the compressed spinal nerves via a lumbar puncture. Repeat injections may be necessary in some patients. The technique necessitates a general anaesthetic.
Some patients with lumbosacral stenosis require surgery in order to relieve pain, hind limb lameness and other clinical signs. Various techniques may be performed, and these aim to remove pressure on compressed nerves and/or stabilise the lumbosacral spine. Removing bone from the top of the spine is referred to as a laminectomy, whilst enlarging the exit holes between the bones (the vertebral foramen) is referred to as a foramenotomy. Bulging disc material and other soft tissues that are compressing spinal nerves are removed. The lumbosacral bones (vertebrae) may be stabilised by the insertion of screws or pins that are secured with metal bars or cement.
- Medical Management – The veterinarian will prescribe anti-inflammatories. He will advise on a modification of exercise such as leash walking only and the avoidance of stairs. Weight reduction, if required, is very important in the healing process. The veterinarian can provide advice on the modification of your pet’s present diet and can recommend a food that will promote good bone health and immunity bolstering. In addition, the suggestion may be to try an epidural infusion of methylprednisolone which has been shown to be successful in mild to moderate cases, with relief provided for up to one year.
- Surgery – The emphasis will be on the removal of the compressed disc, decompression of the nerves, and the stabilization of disc space. This is called a dorsal laminectomy which can be extensive and involves stabilizing the disc space with screws. The outcome is positive and should be considered as an alternative to the medical management if need be.
- Other Management – Whether postoperative or as part of medical management, your veterinarian may recommend other treatments such as hydrotherapy (underwater treadmill), laser therapy or acupuncture.
Recovery of Lumbosacral Disease in Dogs
The outlook for dogs with this condition is good if the treatment was obtained before neurological effects were evident. It should be noted that canines who were experiencing urinary or fecal incontinence may still have the incontinence after the surgery or concurrent with the medical management. This complication is rarely reversed. However, pain and lack of mobility will be reduced or eliminated. The recovery time may take a few months; during this period, exercise will be limited and additional therapies (swimming, underwater treadmill) will be beneficial.