Canine hip dysplasia: new trends in diagnosis, treatment and prevention

Canine hip dysplasia: new trends in diagnosis, treatment and prevention

A question and answer session with veterinary expert Dr. Rory Todhunter
Mar 01, 2009

Ithaca, N.Y. — Canine hip dysplasia affects millions of dogs each year. Abnormal development in the dysplastic hip causes damage to the articular cartilage of the joint, resulting in osteoarthritis, severe pain, lameness, and eventually debilitation. Both genetic and environmental factors play a role in the clinical signs and phenotypic expression.

Rory Todhunter, BVSC, PhD, DACVS, a professor of surgery at Cornell University College of Veterinary Medicine, has spent more than 15 years researching canine hip dysplasia. He spoke with DVM Newsmagazine recently about the disease and the direction of his latest work.

DVM: Are certain dog breeds more prone to canine hip dysplasia? What are some factors that contribute to the development of this condition?

Todhunter: Hip dysplasia is a developmental malformation of the hip joint of any breed of dog, but the ones we usually think of as clinical problems are medium- to large-breed dogs. As reported by the Orthopedic Foundation for Animals (OFA), the incidence of the trait gets as high as 70 to 80 percent in some breeds—most commonly bulldogs—but also Newfoundlands, Saint Bernards, Labrador retrievers, and golden retrievers. At least 85 to 90 percent of the time the conditions involves both hips, but usually one is worse than the other.

Hip dysplasia or any other developmental orthopedic trait has an underlying genetic cause, but there are nongenetic contributions. Nestlé Purina studies that examined the effect of growth rate on the severity of developmental orthopedic traits implied that dogs with a restricted diet had less secondary arthritis, less severe hip dysplasia, and fewer problems in other joints than free choice-fed animals.

DVM: How is canine hip dysplasia best diagnosed? Describe the limitations of current radiographic techniques or other diagnostic tools.

Dr. Rory Todhunter with a patient.
Todhunter: The traditional imaging position, the extended hip or OFA view, is the one most veterinarians are familiar with. You can have dogs that look good in that position, but actually have hip joint laxity, instability, and dysplasia. The University of Pennsylvania Hip Improvement Program (PennHIP) uses the distraction view to measure the maximum laxity in the hip joint. Then, the extended hip view is used to determine whether the dog is dysplastic and if it has secondary arthritis.

Generally speaking, I suggest veterinarians use the extended hip view combined with either the distraction index (DI), the dorsal lateral subluxation (DLS) method, or with physical palpation to make the diagnosis.

The traditional palpation method for young dogs would be the Ortolani maneuver, which is the same maneuver pediatricians use on human infants to determine if there's an instability in the hip. When performing the maneuver, feeling a click or a clunk means the hip is abnormal. But if you have a severely dysplastic hip and you don't have enough structure in the acetabulum, then you're not going to actually feel the click or the clunk. It can also mean that the hip may be out altogether or the dog is just not sufficiently relaxed.

DVM: Please discuss the treatment options for canine hip dysplasia, both surgical and nonsurgical.

Todhunter: If the patient is having clinical signs and pain, nonsteroidal anti-inflammatory drugs (NSAIDs) will decrease the pain and the inflammation, but you want to use them sparingly because of the potential side effects.

You can also use nutraceuticals, some designated specifically for veterinary use. One, for instance, is a combination of glucosamine, chondroitin sulfate, and manganese ascorbate, but there are dozens that you can get off the shelf in health stores. They won't give immediate relief, but over the long term, they may decrease the amount of NSAID needed. There's some evidence that nutraceuticals have anti-inflammatory properties and may help in cartilage regeneration. But you're not going to make an abnormal joint normal; at best, you may help it.