Just a month ago, my girl Boba has surgery to remove a tumor. She already has another one, and it is huge, about the size of a marble. We only first noticed it a few days ago and it has grown to be quite large. We took her to the vet two days ago but for some reason the vet didn't seem to notice it. Is it worth it to get her a third surgery? The vet said it wouldn't be likely for her to survive another one after her first surgery, but she did well after the second. He said that he wouldn't want to risk it again. Is it common for a rat to get three or more surgeries and survive?