Dog Rocks Â® are a 100% natural, paramagnetic igneous rock mined from a quarry in Australia. They contain no chemicals and have been scientifically tested and proven safe for all pets.
In brief: Water. Free fluid is typically water. The lining of your abdominal contents are slippery (your bowel, the lining of your organs) and it's thus wet inside your abdomen. It's normal to have a little free fluid in one's pelvis, as that's where fluid tends to pool.
Now remember; free hydrogen ions are not filtered by the kidney. Instead, they are secreted into the tublar fluid. Because free hydrogens cannot be excreted in the urine easily, there are excreted with weak acids such as H2PO4- which function as urinary buffers.