Which Comes First, Hip Dysplasia Or Arthritis? A Primer For Pet Owners.

PR Log (Press Release) – Jun 13, 2009 – Often, arthritis and hip dysplasia are mentioned in the same breath. The two go hand in hand, but it is important for pet owners to note that arthritis and hip dysplasia are not one in the same.

Arthritis
Also known as Degenerative Joint Disease (DJD), arthritis (or osteoarthritis) is a progressive disease caused by the gradual loss of cartilage. This leads to the development of bony spurs and cysts along joint margins. Many factors play a role in the development and severity of arthritis, including a pet's age, conformation, weight, and overall health. All joints are susceptible to these changes, however it is most often noted in weight-bearing joints of the limbs, such as the shoulders, elbows, hips, and knees.

Pain and inflammation is often associated with arthritis, however those are only secondary signs resulting from a deeper, more complex process. The initial damage occurs long before these signs are noticed, when enzymes within the joint capsule set off a chain reaction of changes leading to collagen degradation, cartilage breakdown, and decreased elasticity of joint fluid. In the end, once the cartilage and joint fluid are no longer able to protect the bone, the friction caused by bone on bone movement damages the bone, thereby causing the pain and inflammation.

Hip Dysplasia
Hip dysplasia is a common cause for the development of arthritis in the hip joints. It is a genetic condition, where the hip joints are not formed properly, leading to a poor fit between the hip socket and the head of the femur. This developmental defect causes the weight placed on that joint to be distributed abnormally, which in turn causes cartilage damage.

To illustrate, think of purchasing a pair of shoes which are too large for your feet. As you walk, your feet move within the shoe, causing additional friction and leading to the development of inflammation and painful blisters. The same problem results for a joint where the bones do not fit together snugly.

So, it is the abnormal motion of the joint with hip dysplasia that then sets the stage for arthritis to occur down the road. However, wether your pet is diagnosed with hip dysplasia or not, it is still possible to have arthritis develop in the hips as a result of other factors (age, weight, traumatic injury to the joint, etc).

Signs that may be seen in pets with either or both conditions include:
Slow getting up in the morning, but improvement with activity throughout the day
Wobbly walk
"Bunny hops" when running
Difficulty going up stairs
Difficulty rising from a lying or sitting position
Muscle loss in the hind limbs
Rocking forward or shifting weight to the front limbs

No matter the cause, arthritis is best approached from a multimodal standpoint. This means developing a well-rounded plan that incorporates exercise, pain management, a well balanced diet, physical rehabilitation, joint supplements, and adjunctive therapies to gain the best possible outcome.