Thromboelastography in equine medicine: Technique and use in clinical research

Abstract

SummaryThromboelastography (TEG) is a viscoelastic, whole blood‐based assay that integrates information from both the cellular and soluble components of coagulation, providing a global evaluation of the haemostatic system. This contrasts with the conventional coagulation assays (i.e. platelet count, prothrombin time [PT], activated partial thromboplastin time [aPTT] and fibrinogen concentration [FIB]), which only provide information about one component (e.g. clotting factors in the case of PT and aPTT) of the haemostatic process, requiring the combination of several assays for a complete evaluation of haemostasis. Thromboelastography is an old technology that has been used in human medicine for over 50 years. However, it is relatively new in veterinary medicine and has only been applied to horses in the last 5 years. Clinical applications in human medicine include diagnosis and monitoring of coagulopathies. Currently, extensive research is being carried out to expand the use of TEG in dogs and cats. Therefore, it is expected that the use of this technique will also further expand in horses in the near future. To date, the available studies in the equine species have evaluated TEG in healthy horses, horses with gastrointestinal disease, septic foals, horses with exercise‐induced pulmonary haemorrhage (EIPH) and a filly with Glanzmann's thrombasthenia. The main objective of this review is to introduce the TEG technique to equine clinicians, providing information on how the TEG functions, blood sample collection and processing, variables measured and their interpretations, normal reference values and areas of potential clinical application.