Thanks for the reply, KAK...basically we have been told the only "cure" is to go in for surgery & try to find the tissue that was left behind. However that is very painful for the cat, and chances of actually finding it are pretty slim. The size of the tissue can be pretty small, and it's kind of like the proverbial "needle in the haystack". But they hadn't mentioned whether they can give a hormonal supplement or something. I think I will ask them about that.