Nina, I am also trying to be proactive with possible incipient kidney disease, and have decided to try the raw food diet with the supplement Food Fur Life EZ Complete. Idjit is being very gradually transitioned (only offering slightly increased amount of the new food one meal a day) and so far, so good.
I have been doing research along the way, and found this thread right here on the board:
http://www.felinediabetes.com/FDMB/threads/diet-for-chronic-kidney-disease-and-diabetes.157741/
I questioned the FoodFurLife staff about phosphorus and CKD and this was the response:
"Regarding your question about phosphorus, the typical guidance for phosphorus in earlier stages of CKD is to feed a food that is less than 1% phosphorus on a dry matter basis, or less than 250mg phosphorus per 1,000kcal. EZComplete is both.
The Veterinary / Rx renal diets typically have phosphorus at lower than AAFCO (which minimum is 0.5% on a dry matter basis). But they achieve this by trading protein for carbohydrates.
If you want to feed a low carb diet, then yes, raw is your best option. In a traditional raw diet with bone, the phosphorus is over 2% on a dry matter basis. This is because bone is used as the source of calcium - but it is also the largest repository of phosphorus in the body. By removing the bone and replacing it with an alternate source of calcium like eggshell (which is what EZComplete premix powder uses), this alone reduces the food to less than 1% phosphorus on a dry matter basis, typically to 0.8% - 0.9% DMB if using very lean meats. You can lower the phosphorus further by using fattier cuts of meat.
That said, Laurie has had 5 CKD cats since she transitioned her cats to raw 7 years ago (half of her crew were seniors when they transitioned), and she now has 2 and Carolina has 1. We've both tried feeding low protein in order to lower phosphorus further (because outside of bone, the organs and meat are the source of phosphorus, which is why the Veterinary / Rx renal diets replace meat with carbs). Lowering phosphorus further in a homemade diet is actually quite easy to do with food made with EZComplete by adding fattier cuts of meat, as mentioned above. If you target 15% fat as fed, the food will have about has much phosphorus as the Rx diets (below the AAFCO minimum), and protein will be around 40% on a dry matter basis - not quite as low as the Rx foods, which are around 30%. At about 10% fat as fed (with food made with EZComplete), the protein will be just about 50% on a dry matter basis. BUT. But it turns out that - in our experience - phosphorus really isn't the only consideration in an ideal CKD food, unless your kitty is late stage 4 or in kidney failure. Again, based on our experience.
We went back to feeding mostly lean meats. Doing extensive research, we learned why our cats do better on the higher protein diet: senior cats need MORE protein, not less. Over time, on the higher fat diet, our cats got weaker in the back end. That's muscle wasting. In a referenced piece by Dr. Mark Peterson, one of the most widely recognized small animal endocrine specialists in the world, he walks through the known needs of senior cats from published studies. It turns out, based on that info, senior cats need a minimum of 53% protein (dry matter basis) to prevent muscle wasting. So we weren't imagining it when our observation was our cats did better on a high protein diet.
https://endocrinevet.blogspot.com/2011/11/optimal-protein-requirements-for-older.html
Dr. Becker has a referenced article on a study conducted in cats, designed to determine if low protein made a difference in CKD. It turns out, protein control does not impact CKD, where phosphorus control does:
https://healthypets.mercola.com/sites/healthypets/archive/2018/02/13/feeding-senior-cats.aspx
So we both feed food made with EZComplete to our cats, using a rotation of chicken breast (lean), chicken thigh (fattier than breast), pork loin (lean), pork shoulder (very fatty), turkey breast (lean) or thigh (fattier), and Laurie uses fatty cuts of beef (chuck beef) and very lean cuts of beef (like top round), and each of us typically feed 2 of 3 meals a day to our cats that are lean, and one that is made with fattier meat.
What we do is control phosphorus by using a specific form of vitamin B3, niacinamide. Laurie lost her 3 prior CKD cats to problems unrelated to the CKD, and the current two have been completely stable for 1.5 years since diagnosis with this approach. Carolina's CKD cat also has hyper-T, IBD, megacolon and a hiatal hernia, and he's been completely stable for two years. Totally stable! Some of it luck-of-the-draw genetically. But this approach has been serving our kitties well."
I found this reassuring and decided to go ahead with the new diet. Best of luck with Dusty.
