Rest and Surgery Can Help Dogs with Disk Disease

Dogs, like humans, are susceptible to painful and debilitating back problems. Disk disease
is most common among small breeds, such as beagles, pekingese, and dachshunds,
according to Dr. Scott Averill, small animal surgical resident at the University of Illinois
Veterinary Medicine Teaching Hospital in Urbana.

"The spine is a stack of bones (vertebrae) interspersed with 'cushions' (intervertebral disks)
and held together by ligaments," explains Dr. Averill. "Bony extensions of each vertebra
form a canal through which runs the spinal cord, an extension of the brain that allows
communication throughout the body. The vertebrae support the animal's torso and protect
the spinal cord. The intervertebral disks act as shock absorbers and allows the spinal
column to be flexible."

Healthy disks are filled with water, collagen, and other substances that provide cushioning
and resiliency. In intervertebral disk disease, the disks lose much of this water and may
even calcify. This type of degeneration begins when the dog is around 7 months old. By age
two years, the disks are fully degenerate. Eventually the disk may rupture into the spinal
canal and compresses the spinal cord. The result is severe pain and compromised
communication via nerve impulses to the body beyond that point.

Ruptured disks are seen most often in the lower back, beyond the rib cage, but about 15
percent of cases occur in the neck. Ruptured disks in the lower back will cause severe
back pain. The rear legs will often be weak, wobbly. Ruptured disks in the neck will cause
the dog to hold its head down in a hunched, motionless position. The signs may appear
suddenly, with a cry of pain when the dog is running, or may progress gradually.
Compression on the spinal cord by disk material will cause pain and cord damage,
ultimately resulting in paralysis.

Treatment depends on the severity and frequency of occurrence. "At the first episode, when
the dog shows just pain or mild weakness, treatment consists of confining the dog to its
crate for 4 to 6 weeks, allowing it outside only to relieve itself," says Dr. Averill. Restriction
of activity will prevent further extrusion of the disk material. Dr. Averill does not
recommend using anti-inflammatories or steroids, which may make the dog feel too good
and encourage activity that worsens the problem. Most dogs that receive crate rest show
some improvement within 3 days.

Surgery to decompress the spinal cord is indicated if cage rest is not successful, if the dog
suffers more than one incident of pain, or if the dog is very weak or paralyzed. The surgeon
makes a "window" in the vertebral bodies and removes all the disk material from the spinal
canal. The prognosis for full recovery following this surgery is very good. Three percent of
the dogs that have had one disk rupture, will eventually have a second one rupture, but this
possibility can be eliminated if the remaining disks are prophylactically removed during the
first decompression surgery.

In cases that don't regain full function, permanent nerve damage has occurred. If the dog
shows signs of such permanent damage prior to surgery, a procedure called a durotomy
can be done to directly view the spinal cord. If the nerve fibers are intact, the dog may
recover; if not, its neurological status will worsen, leading to continued loss of motor control
and potentially of the ability to breathe.

Caring for a dog with severe disk disease takes a big commitment. During the
post-operative period owners will need to catheterize or manually express the bladder three
times a day. If the dog cannot defecate, intermittent enemas may be necessary. The dog
should be turned every 4 hours and given physical therapy, including making a bicycling
motion with the rear legs and walking with the dog's weight supported.

For more information about disk disease in dogs, contact your local veterinarian.