Thanks so much for asking about Ally. I wish I had better news. We had a work-up with the board certified internal medicine vet. She was great and very thorough, and best of all she fell in love with Ally. I think we were lucky to get her back at the end of the visit!
No test results as yet since we were there New Year's Eve. I hope to hear Tuesday about her blood work and a special urine protein/creatinine test. The good news was, her blood pressure is normal, not increased like some kidney dogs. And the vet took a look for herself at her kidneys via an ultrasound without charge, to be able to visualize how affected they are vs just reading the radiologist report. They don't look too horrible she said.
Unforutnately, Ally has gone off her food again. They gave us 3 different kidney diets to try as samples. A few bites of any of them was it. Then we put down the lamb and rice she had been eating, and she didn't want that either. Back on the merry-go-round to find something she will eat!
Tried oatmeal, pasta, chicken, peas, cheerios, eggs. She did eat some raw carrots but there's no calories in that! Today it was a few bites of dog food, some carrots, a dog jerky strip and small slice of broccoli.
The worst part is, she will appear in the kitchen, with big eyes, obviously hungry, but when we offer her something, a few licks and she's done. The Cerenia med doesn't seem to help much. I am going to ask the vet about Phenergan which we use in people for nausea.
They talked to us about an esophogeal feeding tube that would be inserted into her neck to allow us to give her nutrition directly into her esophagus near the stomach. Yowza, at first I thought "no way" but now, with her acting so normally otherwise, we are re-thinking. She still goes on walks, chases her stick, barks and attacks the vacuum.... she's not listless or depressed, just anorexic. Of course without enough calories she will eventually fade. The vet isn't in until Tuesday so we won't know anything before then. It's just very, very, very hard.
So glad Ally is feeling better. I know you said she was not eating well before the antibiotics, so maybe her being sick caused her not to eat. Then the antibiotics cured the original problem but then caused more tummy upset from just being on them. That is my theory. 
