S100A8/A9Prot and S100A12Prot were significantly higher in dogs with TCC/PCA than those with non-neoplastic urinary tract diseases (P = 0.0079 and 0.0485, respectively) or other neoplasms (P < 0.0001 and 0.0056, respectively) but were comparable to those in dogs with a UTI (both P = 1.0000) and healthy controls (both P = 1.0000). This evidence concerns the gene S100A8 and bacterial urinary tract infection.