She is already spayed. We rescued her from the humane society, and they require that before any animal leaves their place that they are fixed. We paid to have her fixed, and what my current vet (whom I trust & like a lot) thinks is that they didn't get all the tissue out. She (my vet) said that to go back in would be very expensive, painful and probably not very successful and we decided against further surgery. So she can't get pregnant, but she can drive us crazy with her hormones. So she goes into these crazy heat cycles at odd times of the year, sometimes only for a day or two. She's a Dr Jekyll/Mr. Hyde kind of kitty when it happens.