Hyperfibrinolysis and Hypofibrinogenemia Diagnosed With Rotational Thromboelastometry in Dogs Naturally Infected With Angiostrongylus vasorum

Background: The pathomechanism of Angiostrongylus vasorum infection-associated bleeding diathesis in dogs is not fully understood. Objective: To describe rotational thromboelastometry (ROTEM) parameters in dogs naturally infected with A. vasorum and to compare ROTEM parameters between infected dogs with and without clinical signs of bleeding. Animals: A total of 21 dogs presented between 2013 and 2016. Methods: Dogs with A. vasorum infection and ROTEM evaluation were retrospectively identified. Thrombocyte counts, ROTEM parameters, clinical signs of bleeding, therapy, and survival to discharge were retrospectively retrieved from patient records and compared between dogs with and without clinical signs of bleeding. Results: Evaluation by ROTEM showed hyperfibrinolysis in 8 of 12 (67%; 95% CI, 40-86%) dogs with and 1 of 9 (11%; 95% CI, 2-44%) dogs without clinical signs of bleeding (P = .016). Hyperfibrinolysis was associated with severe hypofibrinogenemia in 6 of 10 (60%; 95% CI, 31-83%) of the cases. Hyperfibrinolysis decreased or resolved after treatment with 1080 mg/kg tranexamic acid. Fresh frozen plasma (range, 14-60 mL/kg) normalized follow-up fibrinogen function ROTEM (FIBTEM) maximal clot firmness in 6 of 8 dogs (75%; 95% CI, 41-93%). Survival to discharge was 67% (14/21 dogs; 95% CI, 46-83%) and was not different between dogs with and without clinical signs of bleeding (P = .379). Conclusion and Clinical Importance: Hyperfibrinolysis and hypofibrinogenemia were identified as an important pathomechanism in angiostrongylosis-associated bleeding in dogs. Hyperfibrinolysis and hypofibrinogenemia were normalized by treatment with tranexamic acid and plasma transfusions, respectively.