Pet Talk: Back Diseases in Dogs and Cats |  features

A degenerative disease of the back — specifically the lower back, known as the lumbosacral region — is a neurological condition that affects the joint between the vertebrae of the lower back and the sacrum. The sacrum is the bone that lies between the lumbar vertebrae and the coccyx and connects to the pelvis. Dogs and cats have seven lumbar vertebrae. Humans have five lumbar vertebrae. The most common area for arthritis in the spine of dogs and cats is the lumbosacral junction – the area between the seventh lumbar vertebra and the sacrum.

The lumbosacral area is a complex joint that surrounds the spinal cord in the pelvic area. It provides mobility in the lower back and attaches the spine to the pelvis. Degeneration of the disc at the seventh lumbar vertebra causes the disc to protrude into the spinal canal. This is extremely painful. The vertebral processes that overlie the top of the spinal canal in this area degenerate and develop arthritis. The joint can become unstable and even partially dislocate. The end result of these degenerative changes is compression of the spinal nerves that lead to the hind legs, tail, bladder, colon, and rectum. Older to middle-aged large breed dogs are most commonly affected, particularly German Shepherds, but this disease occurs in all breeds as well as cats.

Pain across the lower back and at the base of the tail are the most common signs. Other signs include a reluctance to jump, climb stairs, or get up from a lying position. Hind leg weakness, squatting, paralysis of the tail and urinary or fecal incontinence can also occur. The level of pain and neurological symptoms varies with the severity of the compression.

X-rays are often done to raise suspicion of lumbosacral disease, but only an MRI can diagnose it. Treatment options include lower back surgery or drug therapy. Conservative therapy consists of restriction of movement, anti-inflammatory drugs and drugs to relieve pain. The restriction of movement usually lasts four to six weeks, followed by a gradual return to normal activity. Surgery is a more aggressive treatment option aimed at relieving spinal nerve compression. During the operation, the spinal canal is opened over the compression site and the herniated disc is removed.

The prognosis depends on the degree of neurological symptoms. Dogs with pain as the only clinical sign typically respond well to conservative therapy. Most surgically treated dogs also improved. The outcome in dogs with severe neurological problems is less predictable.

If your dog or cat is showing signs of back pain or hind leg weakness, contact your veterinarian.

dr Karsten Fostvedt is a veterinarian at the St. Francis Pet Clinic in Ketchum.