A system for providing fluid for an animal includes: a generally oval trough to contain fluid, wherein the vertical inner sides of the trough slope inwardly from the upper rim of the trough to the bottom of the trough at an angle that varies around the circumference of the oval, there is an opening in the bottom of the trough in fluid communication with a dip tube that extends into a partially flexible fluid reservoir, and a means of attachment on the underside of the trough by which the fluid reservoir is sealably attached so that when pressure is applied to the reservoir, fluid will flow upward through the dip tube and fill the trough, and when the pressure is released, any remaining fluid will return to the reservoir.A related method is also disclosed.
