This is the link for one of the feline renal failure groups on Facebook. It’s run by a friend of mine and is very, very good:
There is a new test called the SDMA that can detect kidney disease much earlier than the one relying on the creatinine level. You can get your cat’s test results from your vet and start learning about them and also to see if the SDMA was run. The general rule on fluids is that they’re usually started when the creatinine is 3.5 or above, as that’s when cats begin to struggle to hydrate themselves sufficiently by drinking. On the test results, it will be “CRE”. If your cat is significantly below this, you will want to ask your vet why he’s on them as they’re probably unnecessarily working the kidneys.
There are a lot of general practice vets who are woefully uneducated and out-of-date about kidney treatments for cats. This is where the Facebook group comes in, or I can point you to another excellent one on Yahoo Groups. You can determine how educated your vet is by what they recommend, and run things by a group. If you determine you want to switch vets, most likely you can get a recommendation from someone in the group.
You’ll want to keep phosphorus levels low. This you can also see on the test results, it will be “PHOS”. If it’s below six, you’re ok, but may want to look around for a lower-phosphorus food. There are some food lists around, but I can’t find the most recent one so that’s why you’ll want to join a group. It’s complicated, but it’s not the phosphorus amount listed on the label which is why there are food lists. If it’s above six, you’ll need to add binder. You can ask your vet about this. It’s another good litmus test of what your vet knows.
http://felinecrf.org/phosphorus.htm
The best food is one the cat will eat! There are kidney foods, but most of the time cats don’t like them! For now, just keep him eating.
For supplements, there are no magic bullets, but most kidney cats benefit from additional B-complex. You can scroll down to “Which B Vitamins To Give”:
http://felinecrf.org/vitamin_b.htm
It’s a pretty good learning curve, but there are a LOT of non-invasive management things that can be done to give your guy a chance for the longest, happiest life possible.
One of my missions in life is to help kidney kitties and their owners, so please do PM me if I can help you further! The very best of luck.