King- I knew one person that had nearly the same description of the cat as with your sister's. It was horrific, and she was beside herself with what to do. I think she finally had him PTS, rightfully or wrongfully, it wasn't my position to judge, as I had never experienced what she had.

So, my thoughts are with you and your sister. Sometimes....sometimes...you have to look at the whole picture. My best to you guys with this.