Bone Marrow Tests

Why does my dog have to undergo a bone marrow test?

Most of the red and white blood cells are formed in the bone marrow. If a recent blood test indicates a problem with any of the blood cells, a bone marrow sample sent to the laboratory, may indicate the reason.

What are the common reasons for bone marrow evaluation?

The most common reason is persistent shortage of one or more of the various types of blood cells. These include white cells, red cells and blood platelets. By examining the bone marrow the underlying cause can often be determined. 

Cancers can arise in the bone marrow and other types may spread to the marrow after developing in other parts of the body. Therefore examination will help to determine the source of the cancer as well as revealing how seriously the marrow is affected.

Bone marrow samples are sometimes useful in finding the reason for conditions such as recurrent fevers of unknown origin, unexplained weight loss or high blood calcium levels.

How is the sample obtained?

The most common sites are the hip or sometimes the forearm below the shoulder.

A light general anaesthetic is usually used to avoid any stress or discomfort, although sometimes bone biopsies can be performed under sedation and local anaesthetic. The site is shaved and a sample taken through a skin incision using a special needle.

Is the sample examined at the practice?

No. It usually has to be sent to a specialist laboratory. A report is usually received in about a week.

Is this procedure likely to help my dog?

Bone marrow examination is often invaluable in pinpointing the nature of the problem and giving guidance to future treatment. Obviously this cannot be guaranteed and in some cases, although it will confirm the diagnosis, it may not help with future treatment.