Not all cats need to be sterilized. When the cat is 11 years old and has not been neutered, and the female cat has no obvious physical problems or diseases, the breeder does not have to worry and does not need to undergo sterilization surgery in the future. Female cats will have estrus twice a year if they are not sterilized. There is no need for sterilization of 11-year-old female cats. Breeders have a high success rate of finding boyfriends for cats when they are in estrus.