I've been feeding FF Pure which is zero carb and 70"s protein plus regular FF classic. It seems like this is very HP compared to many. Can too much protein be not as healthy as mid level protein?
Dr. Lisa Pierson has a great website on feline nutrition. http://catinfo.org/It's important to know if the protein is animal or plant based. http://catinfo.org/
The answer on protein may depend on what else is going on with the cat. Some cats have renal disease, where what is important is a high quality protein in the earlier stages, and amount of protein in the later stages.