A liner and method of making an animal litter box liner that has a sufficient amount of sodium bicarbonate incorporated into the sheet-like material of the liner to facilitate the control of odors from the litter box when the litter box is used by an animal. The amount of sodium bicarbonate used is small enough that it does not compromise the structural integrity of the liner. The method includes forming first pellets of a first plastic and deodorant. The first pellets are mixed with second pellets and extruded and then formed into liners.