S100A8 and bacterial urinary tract infection: However, the false negative rate of the uCalR in dogs ≥6 years old with a UTI was still moderate (54% and 43% when using ≥5.2 and ≥9.1 as the cut-off concentration, respectively), but a combination of S100A8/A9USG and the uCalR improved the diagnostic accuracy (i.e., specificity) for the detection of TCC/PCA in dogs.