Although I don't have experience with dane, I do have a malamute that is allergic to rice and corn. Definitely try yogurt with live cultures plain non fat, for some reason fat free gives mine the squirts not sure why. With Tonka I use Pinnacle Duck and Potato and 2 red potatos with each meal. With the Giardia, we had that a few months ago, it cleared up in a few days and I was giving yogurt like crazy. Talk to different vets around, I found that where I live there were not a lot of vets that are familiar with mals or other large breeds I lucked up and found a vet from Canada that has a lot of experience with mals and I can honestly say that 99% of the time, she is always open to any suggestions. I feel so sorry for your baby, things will work out have the urine checked again like someone else posted. It took 2 rounds of meds for our UTI to go away and they checked her for 2 months afterwards just to make sure everything was ok.