Ultrasonographic characterization of the urinary bladder in sows with and without urinary tract infection

The urinary bladders of sows (n=10) without urinary tract infection (UTI) were longitudinally transrectally scanned after emptying and refilling with 200, 400, 600 and 800mL saline, and a volume dependence was found for bladder depth (BD), dorsal (dWT) and ventral wall thicknesses (vWT), wall regularity (WR) and mucosal wall surface (mWS). When another 31 sows without and 15 with UTI (as defined on the basis of high bacterial count and macroscopic/biochemical urine abnormalities) were compared for these parameters using BD as volume equivalent, no differences were found. Sows with UTI more often had moderate to high amounts of sediment than animals without UTI. Ultrasonographic assessment of dWT, vWT, WR and mWS of the urinary bladder of sows requires knowledge of bladder volume, and BD may be used as a volume equivalent. However, the parameters are inappropriate for the diagnosis of UTI as defined in this study, while moderate/high amounts of sediment seem to be indicative. Sediment can be visualized by transrectal scanning, but this is also possible using the transcutaneous route.