Hip dysplasia is one of the most common skeletal diseases seen in dogs. It is a congenital disease that can cause lameness and painful arthritis of the joints. It is caused by a combination of genetic susceptibility for hip looseness or laxity and environmental factors. It is most common in large and giant breeds, including the Great Dane, Saint Bernard, Labrador Retriever, and German Shepherd.
Hip dysplasia often begins while a dog is still young and physically immature. In the normal anatomy of the hip joint, the thigh bone (femur) joins the hip in the hip joint, specifically the caput ossis femoris. The almost spherical end of the femur articulates with the hip bone acetabulum, a partly cartilaginous mold into which the caput neatly fits. It is important that the weight of the body is carried on the bony part of the acetabulum, not on the cartilage part, because otherwise the caput can glide out of the acetabulum, which is very painful. Such a condition also may lead to maladaptation of the respective bones and poor articulation of the joint.
Symptoms depend on the degree of joint looseness or laxity, the degree of joint inflammation, and the duration of the disease.
- Decreased activity
- Difficulty rising
- Reluctance to run, jump, or climb stairs
- Intermittent hind-limb lameness
- Narrow stance in the hind limbs
- Pain in hip joints
- Decreased range of motion in the hip joints
- Loss of muscle mass in thigh muscles
Dogs mask pain symptoms until they reach a threshold beyond which they can’t hide it anymore. Your veterinarian may wish to start your dog on medications to decrease inflammation and pain. In dogs with severe hip dysplasia, surgery may be recommended. In young dogs, a surgery to change the angle and coverage of the femoral head by the acetabular cup may be done. In older dogs with severely arthritic hips, total hip replacement surgery may be an appropriate option.