Biological variation of thromboelastrography variables in 10 clinically healthy horses.

This research investigates the use of population-based reference intervals (PRIs) for evaluating thromboelastography (TEG) variables in horses, with data obtained from a biological variation study conducted over five weeks on ten healthy horses.

Methods

• The study was conducted at a veterinary teaching hospital and research facility. The subjects were ten clinically healthy horses randomly selected from a veterinary research and teaching herd.
• The health of the horses was first confirmed through physical examination, complete blood count (CBC), as well as biochemical and coagulation profiles.
• After confirming the horses’ state of health, weekly blood sampling for TEG testing was carried out for 5 weeks.

Results

• Four TEG variables including reaction time (R), clot formation time (K), angle, and maximum amplitude (MA) were measured.
• Coefficients of variation representing within-horse and between-horse biological variation (CVi and CVg respectively), as well as the coefficient of variation for analytical variation (CVa), were calculated using a nested ANOVA after removing any outlier data.
• Index of individuality (IOI) was also calculated for each variable using a formula that takes into account the respective CVi, CVa and CVg values.
• IOI was not assessed for K.

Conclusions

• The study concludes that PRIs are suitable for interpreting TEG variables, R, angle, and MA for individual horses, given the calculated IOI values equal to or above 1.4.
• Although the IOI for K was not calculated, the authors suggest that PRIs are likely suitable for its interpretation.

The research provides valuable information when using PRIs to interpret certain TEG variables in horses. It indicates that it’s possible to apply PRIs in interpreting TEG variables in individual horses, therefore facilitating better understanding of the coagulation process in these animals.