Avascular Necrosis of the Femoral Head
General Information
Avascular necrosis is a disease of the hip joints of miniature and toy breeds of dogs, most often in Poodles. It often develops between 4 and 12 months of age. The disease causes bone destruction in the hip joint, resulting in a roughened, irregular joint surface. Moving the rear legs causes pain, and the leg muscles weaken and shrink from insufficient use. Occasionally the limbs actually shorten. One or both rear legs may be affected. If only one leg is involved, the dog usually refuses to bear any weight on that limb.
Avascular necrosis is hereditary and probably results from breeding for small body size. This selective breeding produces dogs that mature more rapidly, and the early effects of hormones on the developing hips may cause the disease. Some researchers also believe that injury to the developing hips may cause the condition.
If the condition is not treated, the dog may develop severe arthritis in later life.
Important Points in Treatment
1. Symptomatic treatment: This is designed to relieve pain and discomfort during recovery in mild cases.
* Give the medication as directed.
* Exercise should be restricted for ____ days/weeks.
2. Surgical treatment: Excision arthroplasty is the surgical removal of the ball portion (femoral head) of the ball and socket hip joint. It is used to treat more severe cases. Dr. McKee was taught that surgery will usually provide a better long term result. After surgery a "false joint" of fibrous tissue forms. This often increases both comfort and mobility. Mild exercise is advisable immediately after surgery, but keep your pet restrained on a leash.
Notify the Doctor if Any of the Following Occur:
* Your pet's discomfort or lameness worsens.
* Your pet chews at the stitches or irritates the incision.
* Your pet's general health changes.
Understanding Your Pet's Diagnosis
Legg-Perthes Disease (Avascular Necrosis of the Femoral
Head)
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. At this time the ball (femoral head) of the hip joint begins to degenerate. 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.
What are the symptoms?
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 dog
will limp on the affected side(s).
What are the risks?
The hip joint will never be normal and some lameness will always
be present. Arthritis will be the result in the affected joint.
What is the management?
Surgery to remove the diseased bone, i.e. the femoral head, is
successful. The hip joint will not return to normal function however
the destructive arthritic process will be greatly slowed. The
secondary arthritis should be managed similarly to other forms
of arthritis.
The information on this page was obtained from the site www.peteducation.com