Canine Hip Dysplasia is a genetic condition in which the ball and socket joint is malformed, meaning that the ball portion and its socket don’t properly meet one another, resulting in a joint that rubs and grinds instead of sliding smoothly.
All dogs with hip dysplasia develop secondary osteoarthritis of the affected joint(s) – the vast majority of affected dogs have dysplasia of both hips.
Hip dysplasia is the commonest orthopaedic condition in dogs. It most frequently affects large rapidly growing dogs, although smaller breeds can also be affected.
Hip dysplasia is most commonly diagnosed between 6 and 12 months of age. Clinical signs vary and can include stiffness, exercise intolerance, difficulty getting up or lying down, problems climbing stairs and gait abnormalities, including limping on one or both back legs. Affected dogs may experience acute pain during examination when their hips are extended by a veterinary surgeon.
- Early disease (see above);
- Later disease – joint degeneration and osteoarthritis;
- Decreased activity;
- Difficulty rising;
- Reluctance to run, jump, or climb stairs;
- Intermittent or persistent hind-limb lameness, often worse after exercise;
- “Bunny-hopping” or swaying gait;
- Narrow stance in the hind limbs (back legs unnaturally close together);
- Pain in hip joints;
- Joint looseness or laxity – characteristic of early disease but may not be seen in long-term hip dysplasia due to arthritic changes in the hip joint;
- Grating detected with joint movement;
- Decreased range of motion in the hip joints;
- Loss of muscle mass in thigh muscles;
- Enlargement of shoulder muscles due to more weight being exerted on front legs as dog tries to avoid weight on its hips, leading to extra work for the shoulder muscles and subsequent enlargement of these muscles.
This condition is primarily of genetic cause. Obesity in a puppy genetically predisposed to developing hip dysplasia may be a factor, but there is no evidence to show that excessive exercise during puppy-hood contributes to the onset of hip dysplasia development.
However, environmental factors are unable to cause hip dysplasia. The condition is entirely genetic (i.e. breeding).