How should I care for a female cat that isn’t spayed?

If you don’t want to spay your female cat or let her breed while in heat, it’s best to feed her an appropriate amount of estrus-suppressing powder or a cat food that helps inhibit heat before she comes into season. If you do want to breed her, you can let her mate with a male cat during her heat period.

Either way, prolonged heat is very unhealthy for cats. Unspayed females are generally at much higher risk of reproductive-system diseases such as pyometra and vaginitis. If you have no intention of breeding her, the best course is to have her spayed as early as possible.