Hip Dysplasia: What Every Dog Owner Should Know

Many dog owners may have heard the term hip dysplasia in passing. But anyone with a dog should become familiar with this painful hereditary condition. While it’s far more prevalent in large and bully-breed dogs, smaller breeds, especially Pugs, are also at high risk.

What is Hip Dysplasia?

The term dysplasia means abnormal growth; thus, hip dysplasia means abnormal growth or development of the hips. Hip dysplasia occurs during a puppy's growing phase and refers to a poor fit of the ball and socket in the hip. A normal hip consists of the femoral head, which is round like a ball and connects the femur to the pelvis; the acetabulum, which is the socket of the pelvis; the fibrous joint capsule; and the lubricating joint fluid within the joint capsule. The bones (femoral head and acetabulum) are coated with smooth cartilage so that motion is nearly frictionless and the bones glide smoothly across each other's surface. That’s how it should work.

But when a dog has hip dysplasia, the ball and socket do not fit smoothly. The socket is flattened and the ball is not held tightly in place, making the joint unstable and prone to slipping. Over time, the femoral heads will flatten and the sockets will become even more shallow. Bone spurs will develop around the joint capsule as the body attempts to stabilize the abnormal joint.  This progression of the degenerative joint disease leads to osteoarthritis (OA) and becomes increasingly painful.

What Causes Hip Dysplasia?

The primary cause of hip dysplasia is genetic and most dogs with hip dysplasia should not breed as they run a high risk of passing on this hereditary trait to their pups.  However, normal dogs can breed and still yield dysplastic offspring as the condition may skip generations. 

Certain breeds are more prone to hip dysplasia than others.  But whatever the breed, the Orthopedic Foundation of America (OFA) recommends checking hip X-rays to certify that a breeding dog is hip dysplasia free before reproducing. 

How can you tell if your dog is having hip pain?

Dogs who have hip dysplasia generally aren’t interested in much activity, either because the activity causes pain or because they simply can’t physically perform it.  If your dog used to be very active but has slowly cut back on activities, this may be a sign of progressive hip dysplasia.

Dogs with hip dysplasia may have an odd gait, swaying or waddling when they walk. They may also use a “bunny-hopping” gait when running or going up stairs, or walk or run as if they’re wearing high heels.  This is because it hurts to extend the hips too far.

Limping, either constant or intermittent, is always a sign of pain. Your dog may be unwilling to put weight on a back leg, jump up onto furniture, or go upstairs.

Dogs may also sometimes stand with their back legs very close together to minimize the pain.

Signs of pain are often the first symptoms owners notice in dogs who have worsening hip dysplasia. If your dog seems to favor one of their back legs, if their back leg is swollen or hot to the touch, or if they become fearful or aggressive when you try to touch their back legs, these are all signs they are hurting and need to be seen by a vet. 

How can you know for sure if your dog has hip dysplasia?

The first step is an examination with your veterinarian or a specialist in veterinary orthopedics. The vet will likely extend the dog's hind legs backward to check for pain on extension. The dog may be asked to walk around to demonstrate a possible hip swivel or to lie on its back with a hind leg perpendicular to the body. As the leg is moved away from its perpendicular position, a dysplastic hip will make a pop as the femoral head slips to the center of the acetabulum. This pop, which can be felt if your hand is resting on the hip during the exercise, is called an "Ortolani sign.”

True confirmation of hip dysplasia requires radiography, a type of X-ray procedure. The dog must be radiographed on its back with both legs positioned straight down. This posture is often painful to a dog with dysplasia, so sedation is needed to get maximum cooperation from, and comfort for, the patient. 

The radiograph will allow your vet to examine and assess the seating of the femoral heads in the acetabular sockets for OA. In dogs with early signs of hip dysplasia, the femoral heads are not well seated in their sockets. In some puppies, you may already see a subluxation, meaning that the hips are almost completely out of the sockets. 

How is hip dysplasia treated?

Proactive OA management for puppies and young dogs diagnosed with hip dysplasia can include slowing down bone growth by avoiding calcium supplementation during the rapid growth phase. Injecting polysulfated glycosaminoglycans (a prescription form of liquid cartilage, brand name Adequan) has also been shown to protect the cartilage of dogs with hip dysplasia during their first year of life.  Keeping puppies and young dogs slender is also key to comfort. Maintaining a lean, healthy body weight dramatically decreases the rate of OA progression and increases longevity in dogs.

OA management for older dogs diagnosed with hip dysplasia includes relieving pain and maintaining strength and a lean body weight. Dogs with osteoarthritis may also gain tremendous pain relief from a range of physical rehabilitation therapies including acupuncture, shockwave, electrical stimulation, hydrotherapy, targeted exercises, laser therapy, and myofascial release. 

In theory, hip dysplasia could be eradicated through responsible breeding practices, but regrettably that day is still a long way off. If you notice signs of hip pain in your dog, don’t delay. Make an appointment with your veterinarian as soon as possible. 

A Well Adjusted Pet is participating in a clinical trial to evaluate a novel pain management modality called Piezoelectric Shockwave Therapy for dogs coxofemoral (hip) osteoarthritis (OA) pain. A Well Adjusted Pet is currently recruiting patients with altered or decreased mobility, lameness, and chronic pain secondary to hip disease who have not already had physical therapy for hip dysplasia. If you are in the Bay Area and would like to learn more, please contact info@awelladjustedpet.com.