My one rat, Sugar, had surgery on May 2nd. She had 3 tumors removed and was spayed. One of the sites where a tumor was had developed a seroma a few days after surgery, so we had that checked out. We went in on May 15th to have the sutures removed. Doc said everything was looking good. We went in again on May 29th to recheck the seroma, and all was good with that as well. At that time, there was still a small scab where the tumor was, and one where the spay incision was. She's been doing fine, acting normal, eating, drinking, etc... but last night, I noticed a small lump on her belly where they spay incision was. I've attached a pic. Not too sure what it is. I'll be calling my vet, but any input would be appreciated.