Veterinary Student University of Tennessee Royal Palm Beach, FL, United States
Abstract: Background- Dry reagent strips (urine dipsticks, UDS) are an essential component to a complete urinalysis. Despite UDS manufacturers warning that pigmenturia can influence results, the effect of bilirubinuria is unknown. Objectives-Determine the effect of bilirubinuria on UDS analytes and urine specific gravity (USG). Samples- Thirteen urine samples without pigmenturia from client-owned dogs. Eight pooled residual clinical samples submitted for a urinalysis and four pooled samples from healthy dogs. Methods- Urine aliquots were spiked with a bilirubin standard (bilirubin conjugate disodium salt [Sigma Aldrich] in water; SG 1.00) to obtain concentrations of 0, 0.5, 1, 2, 4, 8, and 20 mg/dl. Visual and automated (Siemens CLINITEK Status®) UDS evaluations were performed. Agreement between visual and automated readings was compared with interclass correlation coefficients (ICC). Correlation between urine bilirubin concentration and UDS analyte readings were evaluated using Spearman's rank correlation. Results- Agreement between visual and automated UDS results were excellent for bilirubin (ICC=0.946) and blood (ICC=0.914), good for pH (ICC=0.854) and protein (ICC=0.886), moderate for glucose (ICC=0.550), and poor for ketones (ICC<0.001). Conclusions/Clinical Importance- Bilirubinuria is unlikely to alter interpretation of UDS analytes in a clinical setting.
