2017 ACVIM Forum Research Abstract Program

This study consisted of fifteen healthy dogs and twenty-five dogs with heartworm infection. Heartworm infection was diagnosed using commercial ELISA test kit. Dog with heartworm infection were graded to four groups according to blood work, radiography, echocardiography. Platelet count, prothrombin time, activated partial thromboplastin time, plasma D-dimer concentration, plasma fibrinogen concentration, and thromboelastography were performed in the all dogs. In the results, the value of alpha showed a tendency to increase as the grade increased (table 1, P = 0.03), which indicates higher level of fibrinogen activation in more advanced grades. In the rank coefficient correlation between conventional coagulation tests and TEG, platelet had a significantly positive coefficient correlation with MA and G value in heartworm infected grade 1. An interesting result is that a dog diagnosed femoral arterial thromboembolism showed significantly hypercoagulable state in TEG, compared with conventional tests ( figure 1) . Also, the serial TEG analysis of a dog with disseminated intravascular coagulation represented more hypocoagulable state over time ( figure 2 ). This study suggests that application of TEG is helpful for diagnosis and treatment of heartworm infection in dogs. Ehrlichia canis infection in dogs can manifest with clinical signs related to bleeding and also commonly causes thrombocytopenia. The exact mechanisms of bleeding and thrombocytopenia are unknown but are thought to be related to processes such as vasculitis and immune and non-immune processes on platelets. It is also unknown why some dogs show signs of bleeding while other dogs do not despite significant thrombocytopenia. It is possible that platelets become activated during infection and/or blood clots become resistant to fibrinolysis which could prevent a bleeding phenotype. The purpose of this study was to assess the platelet indices of activation, platelet function via whole blood impedance platelet aggregometry, percentage of immunoglobulin associated platelets (percent IgG), and thromboelastography (TEG) measurements including velocity curve variables in dogs experimentally infected with E. canis.