Retrospective Characterization of Clot Waveform Analysis in Canine Immune-Mediated Hemolytic Anemia Using the Turbidimetric ACL-TOP 300 Analyzer (2018-2022): 35 Cases.

OBJECTIVE: To characterize clot waveform analysis (CWA) parameters (delta and derivative values), alongside standard coagulation parameters (prothrombin time [PT], activated partial thromboplastin time [aPTT], and fibrinogen) in dogs diagnosed with immune-mediated hemolytic anemia (IMHA) using a turbidimetric optical clot detection-based analyzer. DESIGN: Retrospective study from January 2018 to October 2022. SETTING: University teaching hospital. ANIMALS: Thirty-five client-owned dogs diagnosed with IMHA. MEASUREMENTS AND MAIN RESULTS: CWA parameters were characterized by an increased PT delta in 35 of 35 dogs with IMHA (100%) and an increased PT first derivative, aPTT delta, and aPTT second derivative in 34 of 35 (97.1%). Compared with healthy controls, the PT was prolonged and the fibrinogen concentration was increased in most of the IMHA cohort, while the aPTT fell within the reference interval. Of the 18 patients that had D-dimers performed, 17 (94.4%) measured above the reference interval. CONCLUSIONS: CWA of patients with IMHA revealed increased parameters compared with the reference intervals, consistent with a hypercoagulable state. This measurement may be helpful in identifying patients that may benefit from antithrombotic therapy.