Inc. Legg-Perthes disease is a disorder of small breeds of dogs, especially Yorkshire Terriers and West Highland White terriers. With this condition the puppy will grow normally until about three months of age. It is believed that the blood supply to the femoral head decreases causing the bone to deteriorate and actually die.
Similar conditions occur in humans.
The end result is a malformed hip joint and secondary arthritis. Even though the hip joint deterioration begins around three months of age it is not until the puppy is six to ten months of age that it becomes lame. One or both hip joints may be involved. The hip joint will never be normal and some lameness will always be present. Arthritis will be the result in the affected joint.