Evaluation of the effect of etamsylate on thromboelastographic traces of canine blood with and without the addition of heparin.

The objective of this study was to investigate the effect of etamsylate on canine blood and heparinised canine blood from healthy dogs using thromboelastography (TEG). Citrated blood was obtained from twenty healthy client-owned dogs, and 3 experiments were performed. Experiment 1 compared TEG in blood versus blood with etamsylate (250 mM). Experiment 2 evaluated TEG in heparinised blood (1 U/mL) with and without the addition of etamsylate (250 mM). Experiment 3 evaluated dose escalation of etamsylate (control, 250 μM, 500 μM and 1000 μM) in heparinised blood (1 U/mL). The addition of etamsylate to canine blood in experiment 1 increased the percentage of clot lysis at 30 minutes (z =-2.103, p  = 0.035) and 60 minutes (z = -1.988, p  = 0.047), suggesting that etamsylate could have a fibrinolytic effect. When etamsylate was added to heparinised canine blood (1 U/mL), etamsylate produced a dose-dependent inhibition of the effect of heparin when higher concentrations of etamsylate were used (500 μM and 1000 μM). The linear mixed effects model showed significant increases in α angle and maximal amplitude when high dose etamsylate was added compared to the control. In conclusion, etamsylate could be used at higher doses to inhibit the effect of heparin in dogs when protamine might not be available. However, etamsylate might have a fibrinolytic effect when used in healthy dogs.