I just read that's it's an infection of the uterus. Bootsie doesn't have any symptoms other than the belly. I will take her to the vet over the weekend. I will also have her spayed as soon as I know for sure she's not pregnant. I actually hope she is pregnant only because the alternative is so painful the pyrometra. I'm still trying to get a picture of her while she's standing up so you can see both sides of her.