Just wanted to drop off some good thoughts and hugs as you're going through all of this
. Meika is in such good hands - and I know she'll soon be feeling much better than she has recently. You will get her back on track. And her vet(s) sound just wonderful. The fact they even thought of Cushings right away is quite amazing, and speaks volumes as to the depth and breadth of their knowledge.
I've heard nothing but great things about Dr. Remillard. Otherwise, there are tons of high protein kibbles you could go with...I'm not sure if you have a brand you prefer or not, but there may be one in whatever line you're already feeding too.
Hang in there, and puppy smooches to Meika!