Measurements of salivary alpha-amylase in horse: Comparison of 2 different assays

Abstract The aim of this study was to develop and validate 2 different methods (enzymatic vs. time-resolved immunofluorometric assay [TR-IFMA]) for the detection and measurement of salivary α-amylase (s-α) in horses. The analytical validation of the enzymatic assay showed intra-assay and interassay coefficients of variation of 2.5% and 7.2%, respectively, and a limit of detection of 0.045 IU/L. On the other hand, the analytical validation of the TR-IFMA showed intra-assay and interassay coefficients of variation of 5.4% and 9.9%, respectively, and a limit of detection of 0.097 ng/mL. Both assays also demonstrated a high level of accuracy as determined by linearity under dilution. To check the presence of α-amylase in saliva of horses, 3 different models of physical exercises (exercise in a horse walker and 2 different types of dressage) were made in a total of 27 animals. Saliva samples were obtained before, immediately after, and 30 minutes after the physical exercise. Samples were measured by enzymatic assay and TR-IFMA, and both methods were able to detect the enzyme. Only the results of TR-IFMA showed a significant increase ( P P