Addition of Yucca schidigera extract (YSE) products to canine or feline diets improved the character and reduced the intensity of faecal aroma as monitored by a human panel. The general condition of the animals was not adversely affected as monitored by faecal pH, food retention time, and blood cell counts. Blood urea increased significantly in YSE-treated cats, possibly due to the saponins of YSE affecting gut wall permeability. This finding contrasts with previously published reports of a reduction in blood urea on the addition of sarsaponin (from YSE) to rat diets and of YSE products to poultry and cattle diets.