The 1-2 Minute Blood Film Review: Why Is It Important and How Do I Do It?

INTRODUCTION:

Extremely few veterinary practices that have in-house hematology instrumentation prepare blood films for routine microscopic evaluation. Much of this is based upon the lack of confidence in either preparing a well made blood film or the lack of confidence in being able to accurately identify significant abnormalities. The advancement in technology for the in-house hematology laboratory has not encouraged blood film evaluations. In fact, the veterinarian and technician feel more and more confident as more and more data are collected by these instruments. There are instruments that provide 16, 18 and more parameter evaluations as well as a three-part or full five-part leukocyte differential count. It should be noted that none of these instruments, including the large $100-150,000 instruments used in commercial reference laboratories were designed to eliminate the peripheral blood film evaluation.

Clearly the amount of time spent on the microscope is dramatically reduced in the large volume laboratories, but blood film evaluation is still critical to accurate data generation. There are several basic steps to the process. The first and most important aspect is the preparation of a quality blood film to evaluate. If this is not possible, the process of analysis is of questionable value. Basic instructions for slide preparation are listed below: