Endogenous fibrinolytic potential in tissue-plasminogen activator-modified thromboelastography analysis is significantly decreased in dogs suffering from diseases predisposing to thrombosis.

BACKGROUND: In people, studies have shown that resistance to fibrinolysis could be a contributing factor to thrombosis. Tissue-plasminogen-activated (t-PA) thromboelastography (TEG) has been used to evaluate endogenous fibrinolytic potential. In dogs, TEG has been used for the diagnosis of various hemostatic disorders, but studies evaluating fibrinolysis are limited. Investigations into the potential of t-PA-modified TEG to monitor endogenous fibrinolytic potential are lacking in both healthy dogs and dogs with diseases predisposing to development of thrombosis. OBJECTIVES: The aim of this study was to compare 3 t-PA-modified TEG assays and compare the endogenous fibrinolytic potential in dogs suffering from diseases associated with thrombosis with a group of healthy dogs. METHODS: Three different TEG assays, such as native, tissue factor-activated, and kaolin-activated, were modified with t-PA and used to compare whole blood samples from 16 healthy control dogs and 20 diseased dogs. RESULTS: Thromboelastography lysis variables were significantly affected by addition of t-PA in all 3 assays. Lysis results in diseased dogs were comparable to those in healthy dogs prior to addition of t-PA. After addition of t-PA, lysis results were significantly decreased in the diseased group compared with healthy dogs. The lowest median lysis levels were found in dogs with systemic inflammation and protein-losing disorders. CONCLUSION: Addition of t-PA activates fibrinolysis in TEG of blood from both healthy dogs and dogs with diseases predisposing to thrombosis. The significantly decreased fibrinolysis in diseased dogs suggests that this may be a potential prothrombotic risk factor in dogs.