What is Narrowing of Vertebral Canal?
Lumbosacral stenosis puts pressure on the nerves in the spinal canal between the lumbar and sacral vertebrae, damaging them. The condition is rare in cats but can cause pain and lameness in cats that are affected.
The cat's spine is composed of seven cervical vertebrae in the neck, thirteen thoracic vertebrae in the upper back, seven lumbar vertebrae in the lower back and three sacral/coccygeal vertebrae in the pelvis and tail region. Each of the 30 vertebrae has discs inbetween one another, which absorb shock, hold the spine together and act as a joint in order to help the spine move. The spinal or vertebral canal is located in the vertebra, protecting the cord from injury. When this vertebral canal narrows, a neurological condition known as lumbosacral stenosis or cauda equina syndrome results.
Symptoms of Narrowing of Vertebral Canal in Cats
Symptoms typically develop slowly as the vertebral canal narrows. These symptoms include:
- Tail weakness
- Tail paralysis (tail drags on the ground behind cat and can no longer be lifted)
- Abnormal tail carriage
- Hind limb lameness
- Pain in the lower back in the lumbar and sacral spinal regions
- Pelvic limb weakness
- Muscle atrophy
- Ligament hypertrophy
- Urinary incontinence
- Fecal elimination problems
- Reluctance to jump or climb
There are two types of lumbosacral stenosis:
- Acquired, in which the condition develops on its own
- Congenital, in which the condition develops during fetal development and is present at birth
Causes of Narrowing of Vertebral Canal in Cats
Lumbosacral stenosis typically develops due to an injury at the lumbosacral junction that causes spinal instability or disc herniation/protrusion. In cats who are born with the condition, the reason for development is unknown.
Diagnosis of Narrowing of Vertebral Canal in Cats
The veterinarian will need to know the cat's complete health history, a list of symptoms the cat is experiencing and when symptoms first begin. The veterinarian will physically examine the cat, gently feeling its tail and spine for signs of disc herniation and tail paralysis. The veterinarian may have the cat walk in order to examine its gait.
Routine labs will be taken to rule out other conditions that could be causing the symptoms. These labs include a complete blood count, a biochemical profile and a urinalysis. Lumbosacral stenosis typically presents with normal labs.
X-rays and ultrasound may be utilized in order to look for problems in the cat's spine. Because of the limitations of these tests, however, they are typically used to rule out other spinal problems, such as an infection or tumor, rather than diagnosis lumbosacral stenosis. Magnetic resonance imaging (MRI) and computed tomography (CT) can give a definitive result. These tests will show the narrowing of the spine as well as the condition that could have caused the narrowing to occur, such as spinal injury.
Treatment of Narrowing of Vertebral Canal in Cats
If the cat is suffering from incontinence due to the lumbosacral stenosis, the cat will need to be hospitalized. A catheter will be placed in the cat's bladder until the cat has control of its bladder again.
The veterinarian may inject a long-acting steroid called cortisone into the cat's spine. Cortisone will help to reduce inflammation and decrease pain. The veterinarian may also prescribe pain relievers to relieve the cat's pain while the spine heals.
Excess weight can make healing difficult. If the cat is overweight, the veterinarian may place the cat on a special diet in order to reduce weight and promote healing.
If weight loss, rest, and medications don't help relieve the cat's pain and lameness, surgery may need to take place. There are several surgical options that can help relieve the vertebral canal narrowing. A laminectomy may be performed to remove some of the bone at the top of the spine and a foraminotomy may be performed in order to widen the openings of the vertebrae. Tissue and bulging discs that are compressing the spine may also be removed during surgery in order to relieve the pressure. Screws and pins may also be placed in the vertebrae to improve stabilization and prevent narrowing from occurring.
Recovery of Narrowing of Vertebral Canal in Cats
Strenuous movements, such as jumping and running will need to be restricted while the cat heals. The cat will need to be confined in order to prevent these movements from occurring. Walks on a leash should occur regularly in order to promote safe movement. Movement restriction should continue until the cat has healed or for four weeks after surgery.
Dietary restrictions will need to continue in order to help the cat lose weight and prevent weight gain from occurring while the cat heals. Regularly follow-up appointments with the veterinarian will need to take place in order to look for signs of infection after surgery and to monitor healing. With treatment, most cats regain tail and limb movement, though there is a risk that some spinal damage is not reversible.