"Fluid loss" refers to the amount of liquid that is being lost from the body. It can happen due to various reasons such as sweating, urination, or diarrhea. Full definition
It sounds like you have a significant leak based on the rate of fluid loss. (yourmechanic.com)
This will include steps such as restoring fluid balance and providing medications that can help prevent fluid loss from diarrhea and vomiting. (dog-health-handbook.com)
But extremes in weather — like that being experienced all over the country — can increase fluid losses. (australianbeverages.org)