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.
An unopened soda can is virtually bubble-free because the pressure inside the can keeps the carbon dioxide dissolved in the liquid. When you crack open the can, you release the pressure and allow the gas bubbles to wiggle free from the liquid and rise to the surface.