In patients diagnosed with a UTI, S100A8/A9USG, S100A8/A9Cre, S100A8/A9Prot, S100A12USG, S100A12Cre, S100A12Prot, and uCalR did not differ in dogs with a single bacterial isolate (n = 43) from those with a polymicrobial UTI (n = 7; all P > 0.05); and there were no differences seen in dogs where only Enterococcus sp. This evidence concerns the gene S100A8 and bacterial urinary tract infection.