Blood hypercoagulability and systemic inflammation in horses with heaves.

As inflammation and coagulation are intertwined processes, the efficiency of blood coagulation of heaves-affected horses and controls were compared in an observational case-control study, using thrombelastography. In experiment 1 (Exacerbation, six heaves, five controls), horses were housed indoors and fed hay. Thrombelastography, functional fibrinogen, platelet count, hematology, and antithrombin were measured. In experiment 2 (Remission, eight heaves, 11 controls), horses were housed in a low-dust environment for at least a month when thrombelastography was performed. Heaves-affected horses in exacerbation had greater maximum amplitude and higher functional fibrinogen than controls. Heaves-affected horses in clinical remission had greater maximum amplitude than controls. The hypercoagulable state and systemic inflammation of horses with heaves may be a consequence of pulmonary inflammation and may contribute to the perpetuation of airway dysfunction.