Recent research has raised serious questions regarding dietary protein restriction in dogs with chronic renal disease. It appears that another medical myth has bit the dust. The rationale for protein restriction for chronic renal disease patients appears to have been based on flimsy data that has been refuted. The recommendation currently is for high quality protein with restriction applied only in advanced disease.
From a functional perspective, it is important to keep in mind the role of digestive enzymes and stomach acid in protein metabolism. Since most pets with chronic renal disease are older, they often benefit from enzyme and stomach acid supplementation.