His vet appointment is in three weeks and I'm taking the AVA information on Fanconi syndrome with me. We've been very lucky with Rocky. He was a rescue and has become the best family dog. I know the breed is not known for being good with kids but he is so incredibly patient with my two children (3 and 6 months). He even helped teach my eldest to walk by leting her hold onto his shoulders while she toddled along.
I'll keep you guys posted and let you know what's up. We've had him tested for kidney, liver, and renal failure in the past as well as chronic UTI and blood-bourne illness. Nothing… "perfectly healthy dog". We'll keep looking until we figure out what's wrong.
Thanks for all the info!