Prevent cat from coming into heat

Question
We have a cat who is not yet a year old and has come into heat 3 times.  We had her scheduled to be spayed but an x-ray revealed that she has an enlarged heart so we were advised that the anesthesia was risky for her and she may not survive the surgery.  So we canceled the appointment.  I am wondering if there is anything to prevent her from coming into heat.  She really isn't too bad while in heat, but she seems so uncomfortable and we feel sorry for her and would like to do something to prevent it.  She is an inside cat.  Thank you for any suggestions.

Answer
Hi Melody,

Truthfully, the best thing for her is probably to allow her to continue to go into heat as long as she stays indoors. There are medications that can prevent estrus, such as megestrol acetate. But these carry a very strong potential for very serious side effects including diabetes and mammary tumors if used for longer than a few months' time. Estrus doesn't appear to be very uncomfortable, but if you feel her quality of life might be worth the risks that megestrol acetate poses, you could talk to your vet about using it, at least to control estrus during the most active times of year.

Good luck!

Jessica