I really do feel for you Di. It is so, so hard watching them go through this. It makes you feel so helpless - you just want to wrap them up and make them better.
I do hope that she improves over the next couple of days and that maybe the changes in diet have been causing it.
And no, you don't sound heartless - making that decision is the hardest thing of all but if it comes to it, you know that you will be making it out of love and loyalty for Minnie. You know that you are doing absolutely everything possible for her and that counts for so much. But here's hoping that it is a blip and that she will get over it. Keep fighting little Minnie.
((((((((((((((((((((((((Di and Minnie))))))))))))))))))))))))