The degeneration of the vertebrae and other components of the spinal column in dogs can compress the spinal cord running along its length, as well as the roots of the nerves arise from it. This trauma often results in several neurologic symptoms of varying intensity.
Degenerative lumbosacral stenosis in Dogs
This spinal cord disorder affecting the lower back portion of the spinal column results from the degeneration of the lumbar as well as sacral vertebrae. It compresses the roots of the nerves arising from these vertebrae, causing trauma. Mostly the larger breeds are prone to this disorder, but the exact cause of degeneration is not known. German Shepherds are particularly vulnerable to degenerative lumbosacral stenosis.
The symptoms such as weakness in the hind limbs and the tail usually appear in young dogs between the age of 3 years and 7 years. The dog may react in pain on touching or moving the lower back area and may lose control over the bladder. Hind limb reflexes weaken, and loss of muscle mass and sense of paw positioning may occur. The vertebral degeneration can be seen in x-rays, but a CT scan or MRI scan is performed to obtain a much detailed picture. Cage rest for about a month to 6 weeks may improve the condition of the dog in mild cases where painful sensation in the lower back is the sole symptom. Surgical intervention is usually beneficial, but if severe symptoms such as loss of bladder control are already present, surgery may not help resolve them.
Intervertebral disk disease In Dogs
This disorder of the spinal column is due to the degeneration of the disks between the vertebrae. It compresses the spinal cord and the associated nerves, resulting in typical symptoms of spinal cord trauma.
It is a common spinal column disorder affecting almost all the breeds, but early onset is typical in smaller breeds such as Lhasa Apso, Dachshund, Pekingese, Shih Tzu and Beagle. The vertebral disk degeneration usually starts when the dog is just a few months old. By the time it is one year old or more, a slipped disk may occur, resulting in the sudden appearance of debilitating symptoms of severe spinal cord injury. On the other hand, the onset of disk generation is much delayed in the larger breeds, typically beginning after their fifth year or later and then gradually worsening.
The vertebral disks in the neck region and the middle back are more prone to becoming herniated. If it occurs in the neck, symptoms such as stiffness of the neck, accompanied by pain and muscle spasms, may occur. Muscle weakness in the forelimbs and partial to total paralysis of all the limbs are common. If the herniated disk is in the middle back region, the usual symptoms are back pain accompanied by spine curvature, and difficulty in moving. Other neurologic symptoms such as loss of bladder control and weakening of the motor control of hind limbs may also occur. Paralysis, either partial or complete, is a possibility. If the dog is paralyzed, its response to pinching of the toe and the tail is carefully observed to determine whether it still has the sensation of pain or not. Turning the head or barking may indicate painful sensation.
Herniated disks can be detected with x‑rays, but other imaging tests such as myelography, CT scan or MRI scan may be conducted to determine the extent of trauma to the spinal cord and the nerves. If symptoms of severe neurologic trauma are present, immediate surgery is done to relieve spinal cord compression.
In mild to moderate cases where the sensation of pain is still present, cage rest for a few weeks may lead to recovery. Pain relievers and anti-inflammatory medication is not advisable if the dog cannot be restrained, because any decrease in pain and discomfort may encourage the dog to be more active. Even the slightest increase in the activity level may worsen the condition, as the herniated disk may slip further, and compress the spinal cord more. Even after a period of rest, the problem may return when the dog resumes its normal life. The rate of recurrence is as high as 40%.
Corrective surgery may be necessary if rest and medications do not have the desired effect, and if the symptoms are not satisfactorily resolved. If the dog still has sensation of pain in the legs and the tail, surgical correction may lead to recovery. But if the surgery is done two days or more after loss of pain sensation has set in, it may not be as effective in restoring function.