One of the things I've seen both with Gabby and other cats is that you need to give any change in food more than a day or two before you evaluate whether it's a change for the better. Often, you'll see numbers go up before they come back down. I'd give a change a week or two. Also, I'm not seeing the same difference in Tidus' numbers that you're seeing. The pattern on the SS looks pretty much the same to me.