A few more things (sorry if this is too much), as far as the candida - it really does have to be addressed, or it will just continue to grow and infect. Yeast infections don't just go away on their own, unfortunately. So, you could ask the vet to prescribe something INTERNAL for the treatment of a systemic candida (yeast) infection.
I've just been searching everywhere online and am coming up frustrated in terms of what the gold standard is for chronic yeast meds for canines. For example, in humans, a
chronic yeast situation would result in prescribing a once weekly dose of Diflucan for 4-6 weeks -or- 15 days of ORAL Nystatin 3x per day. I see vets giving topical Nystatin but am not seeing clinical evidence of oral. SO, you could ask your vet about what is available to treat the yeast internally. Giving more prednisone, in my mind, is just a red carpet to more yeast in the long run.
Or that nutritionist does sell a "yeast package" (
http://www.askariel.com/product_deta...ans_parasites), I've never tried it, but knowing Susan, it works. Whichever way you go, she needs the probiotics desperately - and since you are feeding potatoes (a simple carb, which is good for the diarrhea, but not so good for the yeast) - it really needs to be addressed somehow.
I know how all of this can get incredibly overwhelming too...so I really hope this is sounding okay...and I know costs can be concerning too...