Comparison of Multiplate, Platelet Function Analyzer-200, and Plateletworks in Healthy Dogs Treated with Acetylsalicylic Acid and Clopidogrel
This thesis is an investigation of the effects of acetylsalicylic acid (ASA), clopidogrel, or combination therapy in six healthy laboratory Beagles using three platelet function tests: Multiplate Analyzer (MP), Platelet Function Analyzer-200 (PFA), and Plateletworks (PW). In this randomized, double-blinded, placebo controlled study, each dog was given ASA 1 mg/kg/day, clopidogrel 2 mg/kg/day, or combination therapy for 1 week each, with a washout period of 2 weeks between each phase. Platelet function was assessed on days 0 and 7 of each phase using MP (adenosine diphosphate [ADP], arachidonic acid [AA], collagen [COL] agonists), PFA (P2Y, COL-ADP [CADP], COL-Epinephrine [CEPI] cartridges), and PW (ADP, AA, COL agonists). Platelet counts were obtained with both impedance and optical instruments. For MP, mean aggregation was decreased for COL and AA with combination therapy and for ADP with all treatments. For PFA, mean CT was increased for the CEPI cartridge with ASA; and for the P2Y and CADP cartridges with clopidogrel or combination therapy. More dogs receiving clopidogrel showed an increase in PFA CT using the P2Y than the CADP cartridge. For PW, mean aggregation was decreased for AA with all treatments; for ADP with clopidogrel or combination therapy; and for COL with clopidogrel. PW results with the two hematology instruments showed almost perfect agreement. In conclusion, all platelet function tests detected treatment effects in some dogs and may have utility for monitoring therapy.