Ultrasonographic estimation of intraperitoneal fluid volume in dogs

The ability of accurately determine intraperitoneal fluid volume would be useful in both research and clinical practice. The purpose of this study was to develop a method by which intraperitoneal fluid volume in dog can be estimated, using ultrasonography. In this survey volume of intraperitoneal fluid in six adult healthy female dogs (mean weight 16.3 kg) were determined after injection of 1000 and 2000 ml of saline 0.9% solution, in their abdominal cavities. Depth of peritoneal fluid was measured in three regions, ultrasonographically. In each region of abdomen, volume was estimated based on geometric formula, using a segment of a sphere volume. In order to generalize the results of ultrasonography, point and interval estimations with 95% confidence interval and calculation error's percent were also calculated using SPSS software. Interval estimation showed each millimeter of ascitic fluid in ultrasonography is equal to 11 to 15 ml fluid in cranial abdomen, 14 to 20 ml in mid-abdomen and 16 to 28 ml in caudal abdomen. The volume estimation with ultrasonography in caudal to the sternum, umbilical area and cranial to the pelvis were 50.9 higher, 10.4 lower and 12.8 lower than actual volumes of 1000 ml, respectively and were 56.9 higher, 5.3 lower and 50.3 lower than actual volumes of 2000 ml, respectively. In conclusion, calculation error percentage was much more in caudal to the sternum and cranial to the pelvis than in umbilical area. As a result, the best location for volume estimation of intraperitoneal fluid was in around the umbilicus.