Hip dysplasia is a diagnosis with which many dog owners are familiar. It is a term that is often feared, yet incompletely understood, by pet owners.

The term “dysplasia” means abnormal growth or development. Therefore, hip dysplasia is abnormal development of the hips. Affected animals are usually born with normal hip conformation, but as they mature, the hips do not grow normally.

The hip is a “ball and socket” joint. The “ball” portion is the head of the femur (thigh bone). The “socket” is the acetabulum (a concave surface of the pelvis). The surface of both the ball and socket portions of the joint are covered in smooth cartilage, which helps to eliminate friction and absorb shock when the joint moves. 

When hip dysplasia occurs, the ball and socket do not fit smoothly together. This incongruity within the joint, which may be due to a flattened acetabulum and/or malformation of the head of the femur, causes instability. Instability can cause discomfort, pain, and an abnormal gait.

In time, as the cartilage of the joint is overloaded, the body attempts to stabilize the joint. This results in arthritis, which can cause mild, moderate, or severe pain.

Therefore, affected dogs may show symptoms when they are young, due to joint laxity, and/or when they are older, due to arthritis formation.

Hip dysplasia is more common in large, stocky breeds of dogs. Small dogs and slender, lean breeds such as greyhounds are rarely affected.

Multiple factors contribute to the development of hip dysplasia in an individual dog. Genetics play a significant, yet complex role. The focus of most breeding programs is to breed dogs with normal hips. Certification programs exist to grade hip X-rays of dogs that will potentially be used for breeding. A genetic test is currently available for Labrador Retrievers.

Nutrition also plays a role in development of hip dysplasia. Predisposed puppies should be fed a diet specifically made for large breed puppies. These diets are designed to slow the growth rate (the final size will be the same, but the rate of growth will be slower). Rich diets, especially those with high levels of protein or calcium, can cause the bones to grow too quickly, increasing the likelihood of malformation.

Exercise level during growth and age at neutering may also influence the development of hip dysplasia, although these parameters are not currently well-defined.

Treatment depends on several factors, including pain level and age at the onset of symptoms.  Many cases can be managed with pain medication, anti-inflammatories, and joint supplements. Physical therapy and massage may also help. Surgical options are available for more severely affected dogs.

It is important to be aware of the symptoms of pain in an affected dog. They rarely cry or whine.  Instead, they may have difficulty rising or lying down, a reduced activity level, or difficulty going up or down stairs. If have noticed these symptoms in your dog, or if you suspect your dog may have hip dysplasia, a veterinary exam is recommended. 

Dr. Kelly Sulik owns and operates Animobile Mobile Veterinary Services in Tryon, N.C. She can be reached at animobiledvm@gmail.com.