Why is bone marrow collected and examined?
The bone marrow produces many of the cells found in blood, including red blood cells, white blood cells and platelets. If abnormalities with any of these components are detected during blood sampling, examination of the bone marrow may be required to investigate the problem.
What sorts of problems justify a bone marrow evaluation?
The most common reason for examining the bone marrow is a shortage of a particular cellular element in the blood. Examining the bone marrow can help determine the cause and may help to predict what the outcome might be. Bone marrow evaluation may also be done to look for certain types of cancer. Some cancers arise in the bone marrow and others may spread to there. Examination of the bone marrow gives a better understanding of the cancer.
Which bone is the marrow collected from?
Although many bones contain marrow, samples are routinely collected from the front leg, just below the shoulder. Other sites where the sample is commonly collected from include the hip bone and the top of the thigh bone.
How is the sample collected?
At the start of the procedure, pets are deeply sedated so that they will remain calm and still during the procedure. This sedative includes pain killers which will provide comfort and ensure no pain is felt during or after the procedure. A small area of hair is clipped away from the skin and this area is surgically prepared, meaning it is cleansed and disinfected. Local anaesthetic is placed under the skin to desensitise the area. A small nick is made in the skin with a sterile scalpel blade and a needle is inserted to take a sample of bone marrow. This small skin opening is then closed with tissue glue which will fall off by itself once the wound has healed. The sample, called a bone marrow aspirate, is spread on a glass slide, dried, stained with special dyes and examined under the microscope.
What is involved in marrow evaluation?
Marrow evaluation is complex and requires specialist interpretation. Information gained includes how active the marrow is, what cells are present and in what proportion, the presence of abnormal cells and any other details that may explain the abnormalities noted in the patient.