Hip dysplasia is a painful, crippling disease that causes a dog's hip to weaken, deteriorate and become arthritic. It stems from abnormal development of the hip joint – a ball-and-socket type joint – in which the head of the femur does not fit properly into the socket. Hip dysplasia can be mild and slightly disabling, or it can be severe and cause crippling arthritis.

Several factors contribute to the development of hip dysplasia. It occurs more in males than females, and is most common in large and giant breed dogs. Some breeds are genetically predisposed to the disease, including German shepherds, Labrador retrievers, golden retrievers, and rottweilers. Environmental factors like type of diet, weight gain and rate of growth also contribute to abnormal hip development.

By definition, hip dysplasia develops in young growing dogs. The earliest age at which clinical signs may be noticed is usually around four months, but some dogs may not show any abnormality until they are mature or even geriatric. Hip dysplasia occurs in young dogs between 3 to 12 months of age and mature adult dogs.

Rapid weight gain and growth and excessive calorie intake may increase incidence of disease.


What To Look For

If your dog has hip dysplasia, you might notice an abnormal gait, reduced function or lameness. Your young dog may exhibit a "rolling" hind leg gait, in which the hips appear to slide up and down like a Marilyn Monroe wiggle. Your pet may also be reluctant to exercise too far or have difficulty going up and down stairs, all of which might seem strange for a puppy. There may be overt lameness on one or both hind legs. Your older dog may show greater exacerbation of these signs and may struggle to lie down or get up from a lying position.

If your dog exhibits any of the following symptoms, consult your veterinarian:

Hind leg lameness (one or both legs)

Swaying or staggering

Discomfort when attempting to lie down or stand up

Reluctance to run and jump

Difficulty rising

Abnormal gait

"Bunny-hopping gait"

Changes in jumping behavior/reluctance to jump

Decreased activity/exercise intolerance

Some dogs can have a clicking sounds that you can hear when they walk or rise to get up

Diminished muscle mass in rear legs (in chronic cases)

Diagnosis

When your dog is examined, your veterinarian will be checking the gait – looking for a lameness while walking or trotting, a "rolling" hind leg gait and difficulty standing up or lying down. Your veterinarian will move the dog's hip joint to assess its range of motion and check for pain with the joint extended, and he or she will listen for the "click" of the hip popping out of joint and the grating sound of bone on bone that indicates cartilage loss.

Radiographs (X-rays) may confirm the hip joint is dysplastic. X-rays will show the degree of dysplasia and the amount of associated arthritis.

In playful young dogs, this thorough evaluation may require sedation or even anesthesia because palpation and manipulation of the hips can be very painful. Also, in young dogs with hip dysplasia, it's possible to dislocate (subluxate) the hip by manipulation due to the poor fit of the ball of the femur in the hip socket.