VWF and anaphylaxis: The secondary objective was to compare coagulation biomarkers; specifically, prothrombin time (PT), activated partial thromboplastin time (APTT), fibrinogen concentration, and activities of von Willebrand Factor antigen (vWF), protein C (PC) and antithrombin (AT) between dogs with anaphylaxis, non-anaphylaxis critically ill dogs, and healthy dogs.