Anyone who wants more info on renal disease and failure and homemade diets, please PM me your email addresses and I will try to pass along all of my info that I have accumulated in my research and my experiences. I had a young dog dx with renal failure at 5 months (as most know) and I lost him at 13 months.
As Jim said, BUN and Creatinine are the two most important numbers on the blood panel.
As someone else said in the beginning of the thread, a homemade diet is better than prescription. In my case, my renal dog's blood calcium was elevated so he was not able to eat the Science Diet K/D due to it being a 3:1 Ca

ratio. Calcium is a natural phosphorus binder. Phosphorus is what damages the kidneys, the nitrogenous waste from the breakdown of proteins. Thus giving people the impression that protein is bad. Rather, what you need is highly digestible proteins. ie. eggs, chicken, and beef being the top three.
Do NOT feed white rice. Go to a store (Wegmans is local to me that carries this) or go online and get Hakubai (I'll double check the spelling) rice. It's similar to an Asian sticky rice and it's super low in phosphorus. I can give you instructions on how to cook as well since it's different than regular rice.
A good, and cheap, phosphorus binder is Alternagel. Go to drugstore.com and find it for like $8 a bottle. My vet didn't carry it. It's a liquid.
There's a ton of supplements you can give as well. Join the Yahoo group, K9KidneyDiet I think. They have tons of info on there and people who have been through it.
That's a start, again, anyone wanting info PM me and I can get you more. Best of luck and as far as the OP is concerned, I hope this is not what you are dealing with. Note that the pale or gray colored gums is a sign of anemia which is caused by kidney disease amongst other things. Something to do with the red blood cell production. You'll need to test the PVC to find out if it's regenerative anemia meaning he can recover. With renal failure anemia it's not due to iron deficiency but again the RBC production and most times the PVC bloodwork doesn't improve that much.