My CKD cat Gabby had a heart murmur (a three on the 1-6 scale), and I had the same reservations about doing the dental and putting her under anesthesia. It's ultimately your decision whether to take that risk with the anesthesia, but in Gabby's case I weighed her quality of life with the rotten mouth with the risk, and decided to do it. She was so miserable with her mouth and it was affecting her eating so I figured that if I didn't do the dental I might lose her anyway. She made it through just fine, and I could not believe the behavior change in her after getting it done. Her rotten mouth was negatively affecting her far more than I even realized--she was like a kitten again after the dental.
Many vets recommend low protein diets for cats with CKD, because they are by default low in phosphorus. However, it's the quality of protein and phosphorus levels that matter, not the protein values. The low-protein prescription kidney diets have only been shown to be beneficial in end stage renal failure and should not be fed long term. In fact, they can cause muscle wasting when fed in early stage CKD and are completely inappropriate for an early stage cat. This is a great page to help you to determine how bad your cat's CKD is:
http://www.felinecrf.org/how_bad_is_it.htm
Here's an updated food list with the values for several premium foods:
https://docs.google.com/leaf?id=0B8...MzhkYTkxOGM4NThk&sort=name&layout=list&num=50. You just need to feed something with less than
less than 250 mg/kcal of phosphorus. Tanya's canned list is great, too:
http://www.felinecrf.org/canned_food_usa.htm. Those numbers are dry weight instead of % of calories, so her list you want something
less than 1% phosphorus. Preferably, you want something low carb, as well, because low carb means more meat and more digestible protein, which helps the kidneys. However, CKD cats are notoriously picky, so you also need to feed what the cat will eat, which may not always be the exact food you want to feed him.
If those are out of your price range the next best thing to feed are the low carb Friskie's Special Diet Turkey & Giblets and Salmon flavors. However, I would
strongly urge a food without byproducts, and keep in mind that they're still cheaper than the prescription foods and usually about the same as many grocery store brands if bought in bulk. Studies have shown that the quality of the protein source does make a big difference in controlling the disease, and that needs to be considered along side phosphorus content. Higher quality protein means the kidneys work less, and slows the progression of the disease.
Here is a fantastic website with a lot of information about CKD:
http://www.felinecrf.org/
