So the good news is that Lucky's not in kidney failure! At our vet appointment last week, they drew blood to do a full blood workup on him to check his kidney values. His blood chemistry numbers had gone a little screwy and we needed to make sure we got him back into the norm.
About a month ago, he had an infection somewhere (we couldn't figure out where, but his white count was very high), so he was prescribed Baytril. I had accidentally given him double his dose of Derramax (I gave him one pill twice a day instead of 1/2 a pill once a day - I almost killed him!) which really did a number on both his kidneys and his GI tract.
The vet advised we immediately cease the Derramax, and instead put him on a different pain killer (tramadol) which was easier on the kidneys. He was also given Sucralfate to help with his stomach ulcers, along with a powder called epakitin, along with plain old Pepcid.
I just got the results of the latest blood work and all the numbers are good! Even the cardiologist liked the numbers, so he can stay on all of his (much needed!) heart medications.
This dog is like a Timex - he takes a lickin' and keeps on tickin'!