Blood clotting problems in 5 cats with cytauxzoonosis infection

Abstract

OBJECTIVE: To characterize hemostasis and determine if disseminated intravascular coagulation (DIC) is present in cats with cytauxzoonosis. DESIGN: Cross-sectional study. SETTING: University teaching hospital. ANIMALS: Five client-owned cats with cytologic and PCR-confirmed cytauxzoonosis. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Admission samples were collected for hemostasis testing including platelet count, activated partial thromboplastin time, prothrombin time, fibrinogen, antithrombin (AT), d-dimer, protein C, plasminogen, antiplasmin, factors VII, VIII, IX, X, and XI, von Willebrand factor, and thromboelastography. Results were compiled for combined criteria used to define DIC, and all 5 cats satisfied criteria using a previously described modified scoring system for DIC in cats. The abnormalities found in all 5 cats included thrombocytopenia, low protein C activity, and prolonged prothrombin time; however, none of the cats had low AT activity. None of the cats had clinical signs of hemorrhage despite thrombocytopenia, coagulation factor deficiency (5/5 cats), and thromboelastographic evidence of hypocoagulability (2/5 cats). Three of 5 cats survived to hospital discharge. The nonsurvivors had disseminated cytauxzoonosis with schizont-laden macrophages in vessels of various organs. CONCLUSIONS: This is the first report that comprehensively describes the hemostastic status of cats with naturally occurring infection with Cytauxzoon felis. All 5 cats had laboratory evidence of overt DIC. Unlike human and canine models of sepsis-induced DIC, AT deficiency was not found in this series of cats. Further research is warranted to investigate therapeutic strategies targeting thrombotic DIC to improve survival in cats with cytauxzoonosis.