Can I give my cat tap water?

Yes. If the tap water is safe for you to drink, it’s safe for your cat. Municipal water is treated to be free of harmful pathogens, and the small amounts of chlorine used in treatment don’t bother cats. Some owners notice their cats prefer water that’s been left out for an hour or two; the chlorine dissipates and the temperature evens out, which some cats like. Filtered water is also fine and may be worth it if your tap water is heavily mineralized or chlorinated enough that you taste it yourself. The biggest variable isn’t water type. It’s freshness and bowl placement.

When to call a vet: if your cat suddenly refuses water she usually drinks, it’s worth a vet check rather than a water-quality experiment.