Keeping Maggie in my thoughts! Good luck, she will be fine.
I know how scary it is to put them under for anything.
I have no personal experience with Life's Abundance. I personally think it's a little low on meat content, for what I would prefer to feed but I don't think there's anything alarming about the food, except it may be a bit grain heavy. And a lot of dogs do wonderful on it, it's just not something I'd feed.
I really like Acana the best out of most kibbles, other ones are Orijen, Nature's Variety, Go!/Now!, Fromm, etc.