Bone marrow is the location within bone where white and red blood cells are produced. Though not always indicated, bone marrow analysis can be an essential feature in the diagnosing, staging and management of your pet. The process involves the removal of a small amount of semi-liquid bone marrow, usually from the humerus (shoulder), so that abnormalities in blood cell production and cancer can be detected. To obtain a sample, a needle is introduced into the marrow space. Aspiration or the removal of a small amount of the marrow is then performed. The test is quick, lasting less than 30 seconds, but can be uncomfortable. Therefore patients are sedated or placed under a light anesthesia to ensure that any discomfort can be avoided. If your pet is scheduled for a bone marrow aspirate please fast them from food beginning 12 hours prior to the procedure.