PERFORMANCE OF THE CELLAVISION^® DC-1V FOR WHITE BLOOD CELL DIFFERENTIALS IN AFRICAN ELEPHANT (LOXODONTA AFRICANA)

Elephants have unique leukocyte morphology, making automated differentiation challenging and unreliable. Manual white blood cell (WBC) differentials are the gold standard in these species. Automated blood film reading systems are now available for blood smear evaluation. The CellaVision^® DC-1V is a computer-controlled microscope that allows WBC preclassification by digital capture and cell recognition, and clinician verification and correction to ensure result accuracy. The aim of this study was to evaluate the performance of this analyzer in captive African elephants (Loxodonta africana) as compared to the gold standard. Sixty blood smears from 7 captive elephants were blindly analyzed twice by 3 observers (MAN: manual counts), and the analyzer (RAW: raw CellaVision DC-1V counts). Analyzer's counts were corrected by each operator (MOD: modified CellaVision DC-1V counts). Linear regressions and correlation coefficients were used to compare MAN, RAW, and MOD. Statistical differences were observed across cell types between all 3 methods (p < 0.01). Heterophil and band heterophil counts were more consistent across observers and methods than lymphocyte and monocyte counts. MOD were considered acceptable for monocytes, but not granulocytes and lymphocytes when compared to limits established for domestic species. The discrepancy between consistency and acceptability may stem from elephants being a monocyte-predominant species, suggesting that limits of acceptability could differ from those applied to domestic species. Time required for the differentials was significantly shorter (p < 0.01) and differentials were subjectively easier to perform when using the analyzer (MOD). The CellaVision^® DC-1V may be a useful tool for WBC differentials in African elephants, improving both accuracy and time efficiency when corrected by a trained observer.