CONTRIBUTOR(S): VetFolio, Vetstream Ltd,
Lumbosacral stenosis
Lumbosacral stenosis
Large-breed, middle-aged dogs (particularly German shepherds) can be affected by lumbosacral stenosis (a compression of the spine in the lower back). This can be caused by a variety of abnormalities, including misalignments, malformations, bony changes/arthritis, or instabilities that compress the spine in the lumbosacral area.
©Animal Health Trust
What is lumbosacral stenosis?
The vertebrae (bones of the spine) in dogs are cushioned in front and in back by disks of cartilage. Occasionally, these disks can rupture (herniate) into the vertebral canal, causing compression of the spinal cord. This condition is broadly referred to as intervertebral disk disease and can affect any area of the spine from the neck to the tail. When it occurs in the lumbosacral area of the spine, it is one of the changes that can lead to lumbosacral stenosis (LSS). The lumbosacral area is in the lower back where the last few lumbar vertebrae (L5, L6, and L7) connect with each other, and L7 (the last lumbar vertebra) connects with the sacrum (the vertebral body that connects the spine with the pelvis). The nerves that originate from there supply the rear legs and tail and are also responsible for fecal and bladder control.
The term stenosis means a narrowing of a space. LSS can be caused by any type of misalignment, malformation, bony change/arthritic change, or instability that causes a compression of the spine in the lumbosacral area. Disc herniation can be involved but is not required for LSS to occur. LSS is painful and can hinder functioning of the legs and tail with some dogs losing the ability to control urination and defecation.
What are the signs of lumbosacral stenosis?
The signs of LSS can vary depending on severity of the condition:
- Pain in the lower back, ranging from mild/moderate to severe
- Pain when rear legs are extended
- Reluctance to stand or walk (especially with the rear legs) or to climb stairs
- Knuckling (walking on the knuckles), scuffing, or dragging of rear paws
- Weakness in rear legs
- Pain when tail is moved or touched; the tail may be held very low or hang limp as if paralysed
- Urinary and/or faecal incontinence or retention
- Aggression (due to pain)
If your pet is in pain, is having problems walking with the rear legs, or is experiencing abnormal urination or defecation (having ‘accidents’ around the house), seek veterinary help immediately.
What causes lumbosacral stenosis?
Lumbosacral stenosis can be a congenital condition (meaning a dog can be born with abnormalities that cause the disease to develop later in life) or it can be acquired. Both forms occur in middle-aged dogs (3-8 years of age for the congenital form, and 6-7 years for the acquired form).
The congenital form is caused by instability in the area or by malformation of the vertebrae that leads to development of LSS. The acquired form is caused by degenerative (commonly arthritic) changes that lead to compression of the spinal cord in the lumbosacral area. Also in the acquired form, wear and tear on the intervertebral disks in the area can cause them to degenerate and eventually herniate into the vertebral canal, causing LSS.
How will my veterinarian diagnose lumbosacral stenosis?
If your pet is showing signs of LSS, your veterinarian may recommend a radiograph (x-ray) to assess the spine. Although narrowing of the lumbosacral space or arthritic changes in the area may be seen on x-rays, this test result can be normal in some dogs with LSS. However, x-rays can help your veterinarian rule out tumors, fractures, and other conditions that can cause clinical signs similar to those of LSS.
Other diagnostic tests may include computed tomography (CT) or magnetic resonance imaging (MRI). CT and MRI equipment are not available at all veterinary practices, so your veterinarian may refer you to a specialist for these tests to be performed.
How is lumbosacral stenosis treated?
Treatment of lumbosacral stenosis depends on the severity of the signs. If pain is mild to moderate and your dog still has control of urination and defecation, your vet may recommend conservative management. This generally means strict rest and confinement for several weeks, with medications to manage pain and inflammation.
If your dog improves initially but relapses, your veterinarian may recommend surgery. Surgery may also be recommended for dogs that are in severe pain, are unresponsive to conservative treatment, or have evidence of reduced urine and fecal control. Once the spinal cord compression is relieved through surgery, the prognosis for return to normal function is good for most dogs. If significant urinary or faecal incontinence has occurred, the prognosis for full recovery may not be as good.
Whether a dog with LSS is being treated with several weeks of medication and rest/confinement or is recovering from back surgery, adequate at-home nursing care is critical for reducing future complications and preserving the dog’s comfort, cleanliness, and overall quality of life:
- Provide soft, padded bedding and frequently turn the pet (every few hours) to help prevent pressure sores.
- Food and water should be offered by hand and held under the dog’s face or placed close by for easy access. The pet may need help lying sternally (propped up on the elbows with the center of the chest on the floor); this position can help prevent accidental choking while trying to eat or drink.
- If the dog can’t control urination or bowel movements, frequent bathing and maintaining clean bedding are required. This can help prevent urine scalding and other complications and help the pet feel clean and dry.
- Dogs that can’t walk are often reluctant to urinate, so even if a dog with LSS has adequate nerve control, it may still hold its urine for too long which can lead to urinary tract infections. Assisting the dog outside frequently to eliminate may be helpful, but this can be difficult if the dog is very large or heavy.
- Antibiotics may be needed periodically to treat urinary tract infections and skin wounds (from urine scalding and bed sores). Your veterinarian may also recommend periodic bacterial culture testing of urine to make sure infections are appropriately treated. In some cases, a urinary catheter may be recommended to facilitate regular bladder emptying.
- If your pet is unable to walk and you are unable to provide at-home nursing care, your dog may need to stay in hospital until its condition improves enough for you to manage your pet at home.
If your pet successfully recovers after medical treatment (rest and medication), actions that jolt the spine (eg leaping and jumping) should be minimised to help reduce the chance of recurrence.