Thromboelastography in healthy horses and horses with inflammatory gastrointestinal disorders and suspected coagulopathies.

This study examines the use of nonactivated thromboelastography (TEG), a method of measuring blood clotting, in healthy horses and in horses with colitis, a type of inflammatory bowel disease, suspected of having coagulation disorders. The results suggest that this form of TEG can detect unhealthy clotting in horses with colitis that were previously known to have coagulation abnormalities.

Methodology of the Study

• The research was a prospective observational study carried out from October 2007 to June 2009 at a Veterinary Teaching Hospital.
• The study subjects comprised of 45 healthy adult horses and 12 sick adult horses suffering from colitis and prolonged prothrombin time (PT) or activated partial thromboplastin time (aPTT), indicating potential coagulation abnormalities.
• The researchers collected whole blood samples from the horses upon admission.
• They then conducted a detailed coagulation profile analysis, which included measuring PT, aPTT, platelet count, fibrinogen concentration, along with citrated recalcified whole blood TEG analysis. The TEG parameters included R-time (R), K-time (K), angle (α), maximum amplitude (MA), G value (G), and lysis at 60 min (LY60).

Results of the Study

• The team measured average values and standard deviations for these TEG parameters in healthy horses.
• The team also calculated the coefficients of variation—a measure of variability—for both the intra-assay and interindividual assessments for the healthy horse group.
• The study found that sick horses with colitis and prolonged PT or aPTT displayed longer mean values for R and K, indicative of a longer time to form a clot.
• They also exhibited a narrower mean angle, lower mean MA, and smaller mean G, all which suggest less clot strength and firmness.
• Overall, these changes are consistent with a state of hypocoagulability, a condition involving decreased blood clotting capability.
• Therefore, the study concluded that citrated recalcified TEG is effective in identifying clotting abnormalities in horses suffering from colitis.

Implications of the Study

• The high interindividual variability observed suggests that measurements can vary widely between different individuals.
• The low intra-assay variability corroborates the reliability of the technique within the same assay.
• The findings also suggest that TEG could be a useful tool for detecting hypocoagulable states in horses with colitis and suspected coagulopathies.