Background Alpacas are increasingly presented to veterinarians for evaluation and care. Reports of alpaca reference intervals for one-stage prothrombin time (PT), activated partial thromboplastin time (aPTT), thrombin time (TT), concentration of fibrin degradation products (FDP), and antithrombin (AT) activities are scarce or nonexistent. Objective The aim of this study was to determine values for blood coagulation times (PT, aPTT, and TT), FDP concentrations, and AT activities in healthy adult alpacas. Methods Of blood samples collected from 35 clinically healthy adult alpacas via jugular venipuncture and placed into sodium citrate and FDP tubes, 29 samples were assayable for coagulation testing. PT, aPTT, and TT were determined by physical (mechanical) clot detection; AT activity was determined using a thrombin-specific chromogenic substrate end-point assay; and FDP concentrations were determined by the slide agglutination method. Results Median values and ranges (minimum-maximum) were determined for PT (8.7 seconds, 6.6-11.2 seconds), aPTT (17.3 seconds, 11.9-22.5 seconds), TT (10.2 seconds, 5.4-16.0 seconds), and AT activity (123.3%, 104.8-144.2%). The mean concentration of FDP was < 8 mu g/mL. Conclusion These values for coagulation times, FDP concentration, and AT activity will provide a useful starting point in the diagnostic evaluation of ill adult alpacas.
