Degenerative Joint Disease and Your Limpy Pooch
By: Carrie Gustavson
University of Illinois College of Veterinary Medicine
Every time I take Cody to her favorite dog park, she runs around like crazy -- slobber flying, smiling from Labrador ear to ear. But the next day, I usually notice, she pays for all that squirrel chasing with a slight limp in her right forelimb. It doesn't slow her down much, but makes it me wonder if our trips to the dog park should be replaced by a kinder, gentler activity.
"Off-and-on lameness is a common sign of degenerative joint disease," says Dr. Ann Johnson, veterinary orthopedic specialist at the University of Illinois Veterinary Teaching Hospital in Urbana. "Dogs show evidence of pain from DJD by limping. Lameness can occur suddenly, or gradually increase over time. It can be persistent or intermittent."
Degenerative joint disease (DJD) affects the articular cartilage, cartilage in a joint that has two very important jobs. The first job is to act as a shock absorber, and the second is to provide a slippery surface for joint motion. If injured, articular cartilage doesn't heal -- ever. Instead, an injury leads to inflammation, swelling, and changes in the joint that make cartilage a poor shock absorber and less able to produce joint-lubricating fluid.
"Dogs generally develop DJD after a primary problem in the joint occurs. Essentially, the arthritic change is the body's defense mechanism against unstable joints," says Dr. Johnson. Primary joint problems that can injure articular cartilage and lead to DJD include hip dysplasia, osteochondrosis (OCD), cranial cruciate rupture in the knee, and traumatic injury.
Treatment of DJD depends on each dog and the severity of the lameness. A veterinarian may need to take radiographs (X rays) of the joints, tap the joint for fluid samples, or perform a computed tomography (CT) scan to diagnose DJD.
"DJD is diagnosed by observing changes on radiographs and treatment is determined by clinical signs," says Dr. Johnson. "Many animals with radiographic signs of DJD are not lame, and may or may not develop lameness as they age."
So regardless of what the X-rays say, if a dog is able to do what she needs to do, there is no need for treatment. On the other hand, Dr. Johnson's recommendations for Cody include rest by restricting all activity until lameness improves, in combination with an anti-inflammatory drug. After that, controlled, moderate, regular exercise will help ward off intermittent lameness. Supplements that may protect cartilage, such as Cosequin, appear to be safe and may also help.
Moderate, regular exercise is an important part of managing DJD. It builds the muscle strength that will help support the joint. "Moderate exercise means an activity not severe enough to cause lameness, for example, leash walks or swimming," says Dr. Johnson. Looks like squirrel chasing is out.
Cody will also have to cut back on one other thing she loves to do -- eat! "The less weight your dog carries, the less stress there is on the joints. Weight loss can help decrease pain and increase function in animals with chronic DJD," says Dr. Johnson.
Medical management in many cases allows a dog to live a relatively pain-free life. But if a dog's lameness progresses to a point where moderate exercise, occasional anti-inflammatory drugs, and weight management are not helping as much, then surgical procedures such as a total hip replacement, joint arthroplasty (removal of a portion of the bone), or arthrodesis (fusion of the joint) can be considered for your four-legged friend.
For more information on DJD, contact your local small animal veterinarian.