2015 ACVIM Forum Research Abstract Program

Surplus canine fecal samples were prepared for analysis by extraction with phosphate buffered saline, 5% newborn calf serum, 1% Triton X-100, and 0.25 mM thimerosal. For analytical assay validation, the limit of blank (LOB), the limit of detection (LOD), linearity, accuracy, precision, and reproducibility were determined. To determine the reference interval, 3 consecutive fecal samples were collected from 40 healthy control dogs The LOB and LOD of the assay were 2.5 and 3.7 mmol/g feces, respectively. The observed-to-expected (O/E) ratios for dilutional parallelism (5 different fecal samples diluted at 1/2, 1/4, and 1/8) ranged from 90.0% to 125.2% (mean AEstandard deviation (SD): 104.4 AE 10.6%). The O/E for spiking recovery ranged from 85.4% to 119.5% (mean AE sd: 105.4 AE 10.4%) for five different fecal samples that had been spiked with 3-BrY standards (2.5, 5, 10, or 20 lmol/L). Intra-assay coefficients of variation (%CV) for five different fecal samples were 4.8%, 5.4%, 12.0%, 13.2%, and 15.2%. Inter-assay %CVs for four different fecal samples were 7.5%, 9.1%, 12.0%, 13.3%, and 14.2%. The reference intervals for the 3-day mean and the maximum fecal 3-BrY concentrations in healthy control dogs were established as ≤23.0 mmol/g feces and ≤38.1 mmol/g feces, respectively.