Avascular necrosis of the femoral head or Legg-Calve-Perthes disease is a disorder that affects young, small breed dogs. The exact cause is unknown but some associating factors are genetic, nutritional, hormonal, or traumatic. The necrosis of the femoral head is the result of an infarction and is usually a unilateral disease (one side). This disease usually affects dogs from 6-11 months of age with some breeds (Miniature Pinschers, Terriers, Poodles, Westies) being more commonly affected. There is also a gender predisposition, with males being more commonly affected.

Dogs with this disease are usually lame in the affected limb with muscle atrophy and pain associated with manipulation of the hip. Radiograph of the pelvis will lead to a diagnosis of this disease due to the bony changes that occur (deformation of the femoral head, degenerative changes of the coxofemoral joint).

	severely misshapen and lytic femoral head

The treatment of choice for most dogs is a femoral head and neck excision or FHO. This procedure excises the femoral head which will eliminate the pain associated with the disease. Most dogs have an excellent recovery from the procedure and have a good prognosis for return to normal limb function. Physical therapy exercises will help encourage these patients to use the limb after the procedure.