ABSTRACT
Complete blood counts are an important diagnostic test used to manage chelonian cases. For this diagnostic test to have value, however, it is important to minimize any potential bias in the testing method. Historically, cell lysis has been found to be a common problem in chelonian blood smears. In cases in which there is significant cell lysis, the white blood cell (WBC) estimate or differential may have little clinical value. In humans, bovine serum albumin (BSA) has been used to stabilize the cell membranes of both red blood cells (RBCs) and white blood cells (WBCs), minimizing the likelihood of cell lysis. The purpose of this study was to determine whether BSA could be used to reduce the likelihood of cell lysis in chelonian blood cells. In this study, blood was collected from the subcarapacial sinus of 11 pancake tortoises, Malacochersus tornieri; stored in lithium heparin anticoagulant; and smeared onto microscope slides to make standard blood films. One smear was prepared by mixing 1 drop of 22% bovine serum albumin (BSA) per 5 drops of blood, and one smear contained no BSA. The slides were examined at ×400 and ×1,000 magnification under light microscopy and evaluated for numbers of intact versus lysed cells. There was a significant increase (P< 0.05) in the number of lysed WBCs in the non–BSA-prepared smears compared with the BSA-prepared smears. There was also a significant increase (P < 0.05) in the number of intact RBCs in the non-BSA-prepared slides compared with the BSA-prepared slides. The difference in RBCs was attributed to an artifactual increase resulting from the dilution of the blood with BSA. Overall, the findings of this study suggest that BSA can be used to minimize WBC lysis in pancake tortoise blood smears, which should help to increase the accuracy of the WBC estimate and differential in these animals.
