S100A8 and bacterial urinary tract infection: S100A8/A9Prot and S100A12Prot were significantly higher in treatment-naïve TCC/PCA dogs with a positive urine culture (n = 5; median [IQR]: 604.8 [392.9–10,353.6] and 39.8 [13.4–870.0], respectively) than dogs without a concurrent UTI (n = 7; median [IQR]: 44.5 [32.4–181.2] and 2.5 [1.1–6.1], respectively; both P = 0.0230), whereas no differences in S100A8/A9USG, S100A8/A9Cre, S100A12USG, S100A12Cre, or uCalR were seen between both groups of dogs (all P > 0.05).