Effects of pre-analytical handling on selected canine hematological parameters evaluated by automatic analyzer.

To assess the effects of pre-analytical handling (storage time and temperature) on selected hematological parameters, whole blood samples were collected in EDTA coated tubes from each of 30 clinically normal male adult beagle dogs. Each sample was separated in 2 aliquots, of which one was stored in ambient temperature (25 ˚C) and the other one was refrigerated (2 to 4 ˚C). Complete blood counts were performed in 1, 2.5, 5, 12, 24, 36 and 60 hr post-sampling for each aliquot of every sample using a flow cytometer. Packed cell volume values remained stable in the samples kept in room temperature (RT), whereas a significant increase was noted in the refrigerated ones 24 hr post-sampling. Statistically significant increases in red blood cell counts were noted after 24hr in the samples stored in 2 to 4 ˚C and after 12 hr in those kept in RT. No significant changes were observed in haemoglobin concentration. A significant decrease was evident only 60 hr post-sampling for the white blood cells kept in RT, but not for those kept in 2 to 4 ˚C. Platelet counts significantly decreased after 24 hr in the refrigerated aliquots and after 5 hr in those kept in RT. The results of this study indicate that storage of blood samples for up to 24 hr in 2 to 4 ˚C is associated with the least artifactual changes.