First, I too had my little girl go into heat a few months after we got her from. Tikki is a MF Ferret and guaranteed spayed. I took her to the vet and he too said there was the possibility of ovarian tissue having been left behind, but the only way to tell was surgery. So, ok, we went with surgery. It was touch and go and the vet didn't think she would make it but Thanks to all of the ferret guardian angels she did. This was almost 4 yrs ago. There wasn't much tissue to be removed but after it was gone she was fine and has been ever since. So it can happen. MF did reimburse for the surgery. Little tip on quick clean ups on new and old accident spots. I use Dow Scrubbing Bubbles or the Lysol version. Takes the spots up quickly and deodorizes at the same time. Just squirt it on and let set for a few moments, use a damp cloth to scrub it up. Walla spot gone. Hugs to all of the fuzzies. Terry and the Sweet 16 [Posted in FML issue 1908]