Introduction

Viscoelastic coagulometers can detect hypercoagulability and hyperfibrinolysis. Greyhound dogs possess unique coagulation characteristics that are uncommon in other breeds. Tranexamic acid may be used to treat hyperfibrinolysis. The objective of this study was to measure viscoelastic coagulation changes in healthy greyhound blood donors using a point-of-care coagulometer (VCM) before and after treatment with oral tranexamic acid.

Methods

Healthy greyhound dogs were enrolled after local ethics approval. Venous blood from 28 greyhounds (average weight 33 kg) was measured at times 0, 2 h, and 4 h on the VCM in a blinded, cross-over design treated with 500 mg PO tranexamic acid or placebo. Dogs with missing data, blood cell concentrations below reference intervals, or undetected VCM values were excluded.

After assessment for normality, a generalized linear model was completed to assess changes between baseline measurements (treated vs. controls) and all time points. Each VCM measurement was used as the dependent variable; independent variables were created for baseline, for each time point, and for the interaction between the control and post-treatment times. Each dog was considered a random variable. P<0.05 was considered significant.

Results

There was no difference in VCM measurements in the placebo group over time. There was no difference between treatment and placebo in CT, CFT, alpha, A10, A20, MCF, and Li30. For Li45 there was only a negative correlation between treatment and control at 2 hours (median [range] placebo=92% [38–100], treatment=60% [21–100]), that was no longer statistically significant at 4 hours (median [range] placebo=92%[0–100], treatment=72% [33–100]).

Discussion

The lysis parameters detected in greyhounds are variable over a large range at time 0. The differences noted in Li45 and not Li30 over time are likely due to small sample size and the wide overlapping range detected on the VCM measurements for these lysis parameters in these 2 groups. In conclusion, the VCM does not demonstrate a clear difference in healthy greyhound blood donors when treated with tranexamic acid at an approximate dose of 15 mg/kg.

Disclosures

No disclosures to report.