Research will be key for your friend before feeding her Fur Baby a vegan diet.
Information from Mary Strauss:
Articles and Studies
Following are links to a series of articles and studies on the roles of protein and phosphorus in the diet of dogs with kidney disease, supporting the idea that reducing protein in the diet does not slow the progression of kidney disease nor prolong life, and is unnecessary unless it is needed to relieve symptoms of uremia (very high creatinine and BUN), or if your dog has significant proteinuria (protein in the urine, in which case moderate but not severe protein restriction is indicated). I have provided excerpts from these articles, but I would encourage you to read them in their entirety if you are dealing with a dog with kidney disease, as many of them contain a great deal more information than I will show here.
More Study Results from the Nutrition Symposium
by Ken Tudor, DVM (6/27/13)
The double-blind, randomized study compared actual kidney function, creatinine (a blood marker for kidney function), body condition and survival time of dogs fed a low protein diet (16%) and those fed a normal diet (22.5% protein). Both diets had the same restricted phosphorus content. What they found was no significant difference in kidney function, blood creatinine levels or survival time between the two groups. As expected the body condition scores were greater for the normal protein group as they maintained more muscle mass. The main determinant of survival time was the level of kidney dysfunction at the time of diagnosis, not the diet.
What is interesting is that the low protein diet in this study was 2-3 percent greater than most of the veterinary diets formulated for kidney disease. That means that muscle loss would be expected to be even greater for pets being fed veterinary kidney diets. The maintenance of muscle mass has implications for maintaining an active lifestyle. Since quantity of life is no different it would make sense to feed kidney patients a normal protein diet to maintain their quality of life. This study also suggests that phosphorus control is more important than dietary protein in kidney patients.
Dogs with kidney problems
by Dr. Lucy Pinkston, D.V.M.
"Because by-products of protein digestion are the main toxins that need to be excreted by the kidneys, an obvious assumption might be that all one needs to do is to cut out the protein and the kidneys wouldn't have any more hard work to do. . . . There is significant evidence, however, that the daily protein requirements actually increase slightly for dogs in chronic renal failure. Therefore, severely restricting the protein for such a dog is likely to result in protein malnutrition,
in spite of the fact that the levels of blood urea nitrogen, or BUN (the primary by-product of protein metabolism) would be correspondingly lower." This article contains a great deal more useful information in easy to read format.
Are High Protein Diets Harmful to a Dog's Kidneys?
from the Veterinary Services Department, Drs. Foster & Smith, Inc.
"The myth that high-protein diets are harmful to kidneys probably started because, in the past, patients with kidney disease were commonly placed on low-protein (and thus low-nitrogen) diets. Now we often put them on a diet that is not necessarily very low in protein but contains protein that is more digestible so there are fewer nitrogen by-products."
The Mythology of Protein Restriction for Dogs with Reduced Renal Function
by Kenneth C. Bovee, DVM, MMedSc
"Morris subsequently developed, produced, and sold a low-protein diet, KD, for dogs with renal failure. He and others were influenced by the erroneous work hypertrophy concept for urea excretion advanced by Addis. While experimental or clinical data were never published to support the value of this or other diets, the concept was broadly accepted without challenge in the veterinary literature."
This article talks about the history of protein restriction, and about 10 recent experimental studies that have failed to provide evidence of the benefit of reduced dietary protein to influence the course of renal failure.
Also see Influence of Dietary Protein on Renal Function in Dogs
by the same author, which concludes, "These results do not support the hypothesis that feeding a high protein diet had a significant adverse effect on renal function or morphology."
Nutrition and Renal Function
from the Purina Research Report
"Dietary Protein and Renal Function: Results of multiple studies indicated that there were no adverse effects of the high protein diets.
" This report also includes information on metabolic acidosis and on the beneficial effects of omega-3 essential fatty acids in patients with chronic renal failure. The complete reports on each of the three studies mentioned in this report are available online, as follows: Effects of Dietary Lipids on Renal Function in Dogs and Cats
; Effects of Dietary Protein Intake on Renal Functions
; and Acid-Base, Electrolytes, and Renal Failure
Your friend may want to consider soaking dry kibble in water (about 15/20 minutes) before feeding so that the dry kibble does not pull moisture from the system. Store any leftovers in the frig until next meal. Do not leave out.
Suggestion's to help dog's with kidney problems: DogAware.com Health: Medical Treatment for Dogs with Kidney Disease
Hope this info helps.