I read the response you got from EZC and am not sure what you find confusing. Based on my previous dialog with this company, they do know what they are talking about. If Know Better Pet Food cannot explain to you about the dry matter percentage of the phosphorus content in their pre-mix, then go back and ask EZC how they arrived at that percentage they quoted you. I am pretty sure they will tell you. In all sincerity, KBPF should be able to explain it to you as well.
The CKD forum can be pretty intense. I am not entirely sure, but I don't think they are complaining about the use of homemade food pre-mixes, so much as they are saying a lot of these supplement companies might not be all that educated in terms of CKD. As far as the commercial CKD foods, their issue is the reduction in protein in order to reduce phosphorus, particularly with CKD cats at the earlier stages.
Speaking of which, what exactly is your cat's phosphorus level?
I would use Tanya's web site - over the CKD forum, to determine if your cat even needs to have a significantly reduced phosphorus intake. Simply put, a cat with Stage 2 CKD, which is the IRIS' base of a creatinine level between 1.6 and 2.8 mg/dl should have a goal of 2.7 - 4.59 mg/dl for the phosphorus level. As the stages raise, so does the level of phosphorus because there is only so much that can be done as kidney function decreases.
Tanya's Comprehensive Guide to Feline Chronic Kidney Disease - The Importance of Phosphorus Control (felinecrf.org)
Your zeal to help your cat is wonderful - just don't overdo it in your attempts to reduce her phosphorus level. And don't forget about phosphorus binders to aide in this process when they are deemed appropriate and necessary.
The CKD forum can be pretty intense. I am not entirely sure, but I don't think they are complaining about the use of homemade food pre-mixes, so much as they are saying a lot of these supplement companies might not be all that educated in terms of CKD. As far as the commercial CKD foods, their issue is the reduction in protein in order to reduce phosphorus, particularly with CKD cats at the earlier stages.
Speaking of which, what exactly is your cat's phosphorus level?
I would use Tanya's web site - over the CKD forum, to determine if your cat even needs to have a significantly reduced phosphorus intake. Simply put, a cat with Stage 2 CKD, which is the IRIS' base of a creatinine level between 1.6 and 2.8 mg/dl should have a goal of 2.7 - 4.59 mg/dl for the phosphorus level. As the stages raise, so does the level of phosphorus because there is only so much that can be done as kidney function decreases.
Tanya's Comprehensive Guide to Feline Chronic Kidney Disease - The Importance of Phosphorus Control (felinecrf.org)
Your zeal to help your cat is wonderful - just don't overdo it in your attempts to reduce her phosphorus level. And don't forget about phosphorus binders to aide in this process when they are deemed appropriate and necessary.