Do cats really need a water fountain?

Not strictly, but a fountain helps some cats and does no harm. Cats evolved with a low thirst drive and many prefer moving water, so a fountain can nudge a reluctant drinker to visit more often. The best controlled study found only a small, non-significant bump in intake on average, so treat it as one tool rather than a fix. The bigger hydration lever is wet food, which is about three-quarters water. If your cat already drinks well from a clean bowl, you don’t need to buy anything.