Effect of Anticoagulant and Storage Conditions on Platelet Size and Clumping in Healthy Dogs

Abstract

Abstract. The potential impact of preanalytical factors, such as type of anticoagulant, storage temperature, and time, on the formation of macroplatelets and platelet aggregates (platelet clumping) in dogs is largely elusive. The objective of the current study was to assess the effect of anticoagulant, temperature, and blood storage time in the light microscopy-generated macroplatelet percentages and the frequency of visually inspected platelet aggregates in clinically healthy dogs. Giemsa-stained blood smears from 70 healthy dogs were reviewed after exposure to different anticoagulants (ethylenediamine tetra-acetic acid [EDTA] vs. citrate), temperatures (25uC vs. 4uC), and storage times (up to 24 hr postsampling). The mean percentage of macroplatelets (platelets with diameter or length $5 mm) was higher (P 5 0.0006) when EDTA was used as the anticoagulant. For either anticoagulant, the mean percentage of macroplatelets was higher (P , 0.0001) at 25uC than at 4uC. Platelet clumping was 1.9 times (P , 0.0001) more likely to occur when citrate-rather than EDTA-anticoagulated blood was examined; regardless of the anticoagulant used, clumping occurred 3 times (P , 0.0001) more often when samples were preserved at 4uC than when they were preserved at 25uC. Storage time did not significantly influence the macroplatelet percentages or the frequency of platelet clumping. The results of this study indicate that macroplatelet percentages in the canine blood should be interpreted in relation to anticoagulant-and temperature-specific reference intervals and that future studies are warranted in order to investigate the clinical relevance of this calculation. In addition, the significant association of citrate with the formation of platelet aggregates may preclude its use for platelet enumeration in the dog.

The preanalytic phase in veterinary clinical pathology

“…Reports on effects of refrigeration on hematology results are controversial, for example, for WBC in dogs . The canine platelet count has been reported stable for 3 days, however in canine blood, platelet clumping was enhanced in refrigerated specimens …”

Effect of storage conditions on prothrombin time, activated partial thromboplastin time and fibrinogen concentration on canine plasma samples

“…Therefore, the potential impact of pre-analytic factors such as storage temperature and time in the measurements need to be taken into account. Previously, the effect of anticoagulant and storage conditions on platelet clumping has been evaluated in dogs [11] and the stability of canine plasma stored at room temperature or at 4℃ for hemostasis testing has been investigated at 24, 48, 72 and 96 h post sampling [6]. Additionally, the effect of long-term storage at -20℃ [16] and that of 6-month storage on hemostatic function testing [2] in the dog have been reported.…”

Giant Anteater (Myrmecophaga tridactyla Linnaeus, 1758) of the brazilian cerrado: hematology and storage effect

“…In those cases, activation and posterior thrombocyte aggregation occurs, leading to pseudo thrombocytopenia (Dusse et al 2004). In some cases, leaving the sample at room temperatures before the performance of the analysis minimizes these differences (Mylonakis et al 2008, Wills & Wardrop 2008.…”