As some of you know, Katie was recently diagnosed as having a heart murmur.

Tomorrow morning at 11 a.m., she's going back to the vet for a full blood test and a second stool sample. So hopefully that will shed some light on her condition.
But she has also lost weight. She went from 2.6 lbs (a healthy weight for her petite size) down to 1.14 lbs. For a dog as tiny as she is, this is a tremendous amount of weight to lose. When I pick her up, I can feel her ribs and hip bones. It's so terrible and it just breaks my heart. So I'd like to get your advice on what to feed her to help fatten her up a bit. I can't sit back and wait for the test results. I have to start helping her now. ANY suggestions are greatly appreciated!