Precision of the Advia 2120 for the complete blood count of African elephants (Loxodonta africana)

Elephant leukocytes exhibit distinctive morphologic features, including unique heterophils and monocytes, which pose a particular challenge for automated CBC analysis. Therefore, most automated analyzers cannot correctly identify elephant leukocytes. Many zoologic institutions have turned to manual methods for elephant leukocyte differential count, but these methods are prone to error and are time-consuming. The Advia 2120, a flow cytometry automated hematology analyzer, has the advantage of offering preprogrammed species-specific cell-gating parameters that should allow for correct cell differentiation. This study aimed to evaluate the precision (within run and between run) of the Advia 2120 for use in captive African elephants (Loxodonta africana). Whole blood samples were collected in K2 EDTA from three healthy adult female African elephants. Repeatability and reproducibility were excellent for most variables. Coefficients of variation were >10% for absolute reticulocyte counts, eosinophil counts, and basophil counts, which is expected with cell types that appear in low numbers in peripheral blood. Future studies investigating the accuracy of the Advia 2120 in elephants are necessary.