Had a quick question about these supplements I'm giving Whiskey. Do they slow down creatinine reduction?
You meant "slow down creatinine increase", I'm assuming? If so, yes, they will help. Of course, each dog is different in their response to the supplements. My view is that at the very least, they will not hurt him.
On to your second question, which is the more difficult one. IMHO, there is really no way to know what would be Whiskey's normal, as in will his creatinine plateau at some point. I am afraid that at this point, with Whiskey you might never see his creatinine fall within the normal range set for dogs
But from what I have heard of Whiskey, he will live his life to the fullest and that attitude, believe it or not, will pull him through a lot. Regarding the sub-q fluids and how long to continue... this is the reason why many of us ultimately learn how to administer sub-q fluids at home. Once you have one of the vet techs show you how to do it and you do it under their watch a couple of times, it is pretty easy, so long as the dog remains calm. This way, you can do this therapy for the long term.
Another possibility is to go for a supplement called Azodyl. This was extremely helpful for Wolfie, in extending his life and more importantly, in improving his quality of life. It is expensive though, at least here. Azodyl is considered to be like a "dialysis in a pill". Also, Epakitin will help support the kidney function and reduce the phosphorus levels better.