Hip dysplasia (HD)
The word "dysplasia" means "developmental abnormality". Hip dysplasia is a canine genetic disease in which there is a tendency for hip laxity to develop early in life. Hip dysplasia is not congenital because affected dogs are born with morphologically normal hips. The soft tissues (ligaments and joint capsule) that normally stabilize the hip joint become detached during the first weeks of life.
The consequence of this laxity of the hip joint to the normally very congruent kneecap becomes much less congruent. The head of the femur deforms and flattens as the movements become more difficult and painful. All dogs with hip dysplasia develop secondary osteoarthritis of the affected joint. The vast majority of affected dogs have dysplasia of both hips.
What is the cause of hip dysplasia.
This condition is primarily genetic in origin, although environmental factors such as obesity during the puppy period can influence the development of a clinical problem in an animal with the genes encoding hip dysplasia. Current estimates indicate that more than a hundred genes code for hip dysplasia. It is important to recognize that environmental factors are incapable of causing hip dysplasia, although they can influence the development of a clinical problem in an animal whose genes code for hip dysplasia. There is no evidence that excessive exercise while the puppy is growing can contribute to the development of hip dysplasia, but there is some evidence that early castration can have serious consequences for your growing puppies.
How is hip dysplasia diagnosed?
Hip dysplasia is diagnosed, in most cases, following a multi-modulus assessment process between you, your veterinarian, and a specialist orthopedic surgeon.
In the first case, you may have noticed that your dog is exhibiting some or all of the following clinical signs;
Difficulty getting up, sitting or lying down
Difficulty going up stairs or getting in and out of the car
Abnormal gait - Sometimes described as a 'swaying' gait while walking
Limpage on one or both hind legs
Protector of the hip area during grooming or bathing
Pain - not necessarily in all dogs
Your vet may have recognized an abnormal gait or hip pain noticed in your dog during routine health checks or concerns raised by you. If your vet has a suspicion of hip dysplasia, they may perform x-rays of your dogs hip joints. X-rays usually show changes in affected dogs, although this is not always the case. More often than not, your dog will be seen by a specialist orthopedic surgeon.