[107barney]

Rachel
I can understand your dilemma and I know what it feels like to be tightly budgeted. At the same time, though, I think you have to weigh whether you are being penny-wise and pound-foolish. It's been my experience that things left untreated or guessing just result in further problems down the road that ultimately cost more money.

I think I'd go back to basics if I had to weigh the options as you are -
I'd go back to the simple diet - either turkey or chicken with potatoes or rice. If you think she's really food sensitive, go for potatoes.
As you might imagine, I'm going to tell you not to do mashed potatoes. Just microwave a sweet potato or yam 3-4 mins each side and cube it. Mix it with cubed or shredded and chopped chicken or turkey. Stop the probiotics as WM said because sorbitol is a sugar-alcohol and causes runny stools. I'd do the cerenia, the flagyl, and I'd add pepcid AC.

I'd give this ONE WEEK and if there were NO improvement, I think you have to spend the money and do the fecal profiles in their completion and act for the best interests of your dogs, even if it means putting their interests above your own. You owe it to them to do so.