@wizard
Do you have the article? Or the name of it?
First, even people who feed raw still aren't feeding 100 percent protein. Most add in other stuff. But a whole chicken (skin and meat) is only 40 percent protein. Meat only is 60 percent.
Obviously you have to define "high protein." But if 30 or under, research for the last 30 yrs has pretty much shown the opposite. Even with dogs who already have renal issues they don't support going too low.
https://www.ncbi.nlm.nih.gov/pubmed/3702209
These results do not support the hypothesis that high protein feeding had a significant adverse effect on either renal function of morphology in dogs with 75% nephrectomy.
https://www.ncbi.nlm.nih.gov/pubmed/1941208
These results do not support the hypothesis that feeding a high protein diet had a significant adverse effect on renal function or morphology.
The more in depth studies can make your head explode. Depends on the dog that is sick, depends on diet BEFORE kidney disease. But they don't note if they are doing any control for quality of the meat source... which other studies indicate are a major part.
http://todaysveterinarypractice.navc.com/acvn-nutrition-notesnutritional-management-of-chronic-kidney-disease-in-cats-dogs/
Protein quality:
http://www.vetmed.wsu.edu/outreach/Pet-Health-Topics/categories/diseases/chronic-kidney-disease-and-failure
Feeding of a kidney diet is usually recommended. Kidney diets contain less protein compared to other diets and the protein is high in quality. It is protein in the diet that is converted to waste products that the kidneys must remove in the urine. The higher the quality of the protein in the diet, the less wastes created for the kidneys to eliminate. Low quality protein requires the kidneys remove more wastes. which makes them work harder. Egg and meat contain higher quality protein; cereal grain protein is of lower quality which leads to more wastes for the kidneys to eliminate. <<
For healthy dogs:
Pet Food Safety: Dietary Protein by Dorothy LaFlamme, DVM, PhD, Dipl ACVN
"Summary and Conclusions: Based on a comprehensive review, there remains no evidence that dietary protein causes kidney damage, or any other adverse effects, in healthy dogs. Even in dogs with chronic kidney disease, dietary protein does not appear to contribute to kidney damage. However, in chronic kidney disease, there can be an accumulation of byproducts of protein metabolism, which may contribute to uremic signs. Hence, in those patients, dietary protein restriction may be of benefit. On the other hand, dietary protein is important to support normal protein turnover and maintain lean body mass. Healthy, aging dogs have an increased requirement for dietary protein. When insufficient protein is provided it can aggravate the age-associated loss of lean body mass and may contribute to earlier mortality. Unless medicatlly indicated, intake of dietary protein should not be restricted."
But things I find agree that much over 30 percent may be more than a dog can normally handle.