Pet Water  Hydration is as important to an animal as it is to a human being. In pets, as in people, water makes up the majority of the body about 80%. By allowing substances tod issolve and be carried through the body, it provides the basis for nearly all of the processes and chemical reations that keep the body running, including digestion and ciruclation. It helps the body to filter out waste, and it regulates body temperature through evaporation. Dehydration, a lack of water in the body, can cause serious problems, including kidneyand heart damage.