Disclaimer: I am not a veterinarian, nor do I have any formal training in any medical field. The information presented here is not meant to replace your vet’s advice or prescribed medications, but only to suggest additional options to explore, based on your dog’s condition. 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. 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 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.
Effect of amino acid supplementation on general parameters and fractional excretion FE of electrolytes and urea. Lack of glomerular hemodynamic stimulation after infusion of branched-chain amino acids. For the surgery, rats were shortly anesthetized with isoflurane. Singh, P. What they found was no significant difference in kidney function, blood creatinine levels or survival time between the two groups. Angiotensin converting enzyme inhibitors usually enalapril are frequently used to decrease the degree of proteinuria. At week 4, GFR was measured and the animals were then shifted for the end of the experiment to modified diets as described below and on which they remained for the rest of the experiment.
The metabolism of dietary proteins generates waste products that are excreted by the kidney, in particular nitrogen-containing urea, uric acid, ammonia, creatinine, and other metabolites such as phosphates, sulfates, and protons. Kidney adaptation includes an increase in renal plasma flow RPF and glomerular filtration rate GFR and represents a burden for diseased kidneys increasing the progression rate of CKD. Whereas the RPF and GFR measured in free moving animals remained stable during the course of the diet in rats receiving the control mix, these parameters decreased in animals receiving the branched chain amino acid BCAA supplementation and increased in the ones receiving the aromatic amino acids AAAs. These animals receiving BCAAs also showed an increase in plasma free fatty acids pointing to a problem at the level of energy metabolism. A high dietary protein load increases both renal plasma flow RPF and glomerular filtration rate GFR acutely and in the long term, and increases renal expression of proinflammatory genes Hostetter et al. In the case of Dahl salt-sensitive rats, high protein diet has been shown to increase immune cell infiltration of kidneys, blood pressure, and kidney damage De Miguel et al. Interestingly, not all proteins equally induce hyperfiltration and some of their constituent AAs, for instance, branched chain amino acids BCAAs appear to be less effective than others Claris-Appiani et al. There is however a lack of recent studies investigating underlying mechanisms Alvestrand and Bergstrom, ; Friedlander et al. Nonetheless, it appears crucial that renal adaptation to protein intake, including hyperfiltration, is necessary for the excretion of the nitrogenous end products urea, ammonia, etc. This adaptation involves the combined effects of the hormones vasopressin and glucagon that together contribute to efficient urea excretion and water economy Bankir et al.