Oh, Alyssa, I hope Sara is continuing to feel good. I can't remember how old she is, but Scout, who is my parent's dog has the same problem. Scout is about 10 years old, and is spayed. She started her problem when she was staying with me a year or so ago, and my vet put her on a hormone treatment that she takes twice per week. As long as they give her the medication on schedule, she doesn't have any problems. I can't remember what the name of the medication is, but I know it is no longer manufactured, and my vet has found a druggist (pharmacist) who will make up the pills for him, so I get them for Scout and send them to Mom and Dad for Scout. Let me know if you need me to get more info on that medication for you.
And give Sara a big kiss from me.
Logan