Background: Thrombin plays a central role in hemostasis and thrombosis. Calibrated automated thrombography (CAT), a thrombin generation assay, may be a useful test for hemostatic disorders in dogs.
Objectives: To describe CAT results in a group of healthy dogs, and assess preanalytical variables and biological variability.
Animals: Forty healthy dogs were enrolled.
Methods: Lag time (Lag), time to peak (ttpeak), peak thrombin generation (peak), and endogenous thrombin potential (ETP) were measured. Direct jugular venipuncture and winged-needle catheter-assisted saphenous venipuncture were used to collect samples from each dog, and results were compared between methods. Sample stability at -80°C was assessed over 12 months in a subset of samples. Biological variability of CAT was assessed via nested ANOVA using samples obtained weekly from a subset of 9 dogs for 4 consecutive weeks.
Results: Samples for CAT were stable at -80°C over 12 months of storage. Samples collected via winged-needle catheter venipuncture showed poor repeatability compared to direct venipuncture samples; there was also poor agreement between the 2 sampling methods. Intra-individual variability of CAT parameters was below 25%; inter-individual variability ranged from 36.9% to 78.5%.
Conclusions: Measurement of thrombin generation using CAT appears to be repeatable in healthy dogs, and samples are stable for at least 12 months when stored at -80°C. Direct venipuncture sampling is recommended for CAT. Low indices of individuality suggest that subject-based reference intervals are more suitable when interpreting CAT results.
Keywords: Canine; hemostasis.
© 2018 American Society for Veterinary Clinical Pathology.