Thromboelastography (TEG) for Early Detection of Hemostatic Abnormalities in Horses with Colic
Hemostatic changes are common in horses with colic, and frequently result in secondary complications such as disseminated intravascular coagulation (DIC), thrombophlebitis, or laminitis. Recently, horses with severe gastrointestinal disorders had widespread intravascular fibrin deposits, with evidence of hypercoagulation and reduced fibrinolysis (Cotovio et al. 2007). Thrombelastography provides data about the entire hemostatic system, from the beginning of coagulation through clot formation, and fibrinolysis. The purpose of this study was to evaluate and compare the hemostatic parameters using TEG in healthy horses to those in horses diagnosed with colic.
Blood samples were collected from horses with colic (n=25) upon admission to the emergency service. Samples were collected into 2.7 ml Vacutainer tubes containing 3.2% buffered sodium citrate; they were placed in the thrombelastographa (TEG)® cup and recalcified by adding CaCl2 30-120 minutes after sampling. A group of healthy horses (n=25) based on normal physical examination and clinical pathology were used as controls in this study. CBC, plasma fibrinogen concentration, prothrombin time (PT), and activated partial thromboplastin time (aPTT) were performed. Specific TEG parameters including R-time, K-time, angle, MA, "G" value and LY60 value were compared between groups.
There were significant differences (p<0.05) in TEG parameters between the horses with colic and the control group; horses with colic had higher platelet count, higher fibrinogen concentration, shorter "K-time", wider angle "α", and increased maximum amplitude (MA) and "G" value, changes consistent with hypercoagulability. However, there were no significant differences in fibrinolysis, as evaluated by the "LY60" value.
In conclusion, thromboelastography can be a useful test to detect early hemostatic changes such as tendency to hypercoagulability, in horses with colic.