Caveat: Even when the urine contains no viable microbes, hematuria, pyuria and proteinuria associated with compensatory inflammation are likely to be present. Therefore, one cannot rely on examination of urine sediment alone to detect elimination of bacteria following three to five days of therapy since persistence of reduced numbers of bacteria may fall below the limit of detection by light microscopy.

Dr. Osborne, a diplomate of the American College of Veterinary Internal Medicine, is professor of medicine in the Department of Small Animal Clinical Sciences, College of Veterinary Medicine, University of Minnesota.