Some time ago, we noticed that when we filled our recirculatling kitty water fountain with filtered water the cats would seek out the dog’s water dish full of tap water. When we switched over to tap water in their fountain, they stopped drinking from the dog’s bowl. A recent study proved exactly what we had discovered by accident—that cats would rather drink tap water (Drinking Water Preferences in the Cat. Wooding B, Mills DS. Proceedings of the 6th International Veterinary Behavior Meeting, June 2007). The double blinded study compared a group of cats’ preference between tap water and filtered water. The cats overwhelmingly chose the tap water over the filtered water. So just like some people with their beer, your cat most likely prefers it “from the tap”.