Here's why:

* Essential for life: Water is crucial for all living organisms, including animals. It plays a vital role in numerous biological processes, including:

* Transport: Water carries nutrients and oxygen to cells and removes waste products.

* Temperature regulation: Water helps regulate body temperature by absorbing and releasing heat.

* Chemical reactions: Water acts as a solvent and participates in many chemical reactions within the body.

* Cell structure: Water is a major component of cells and helps maintain their shape and function.

While there are other inorganic compounds important for animals, like minerals, water stands out as absolutely essential for survival.