In part 4a of this series I started “Can we feed too much protein to our companion animals? Expert Opinions” As I had promised following in subsequent parts are various view points on this controversial topic explained by their expert owners: Today I am continuing with Dr. Wysong’s, D.V.M.thoughts. He took a look at the impact of protein intake on kidney related problems. Many pet owners are under the impression that protein causes kidney disease in older animals. This is because their vets promote the idea that food containing high levels of protein causes a progressive decrease in kidney function as animals get older. Consequentially they suggest and prescribe low protein diets for senior pets.
Dr. Wysong adds to that “The conclusion has been deduced from studies in rats, which have shown high protein diets may cause kidney lesions. Additionally, it is known that once animals have kidney disease, protein restriction may help alleviate signs.
However, it does not logically follow that an experimental result on one species of animal, in this case rats, can be extrapolated to other species. Secondly, the fact that protein restriction helps in pre-existing kidney disease does not equate to protein being an etiological cause of kidney disease. In one study, thirty-one dogs were divided into two groups and studied for four years after they had reached seven to eight years of age. Half of the group was fed a diet consisting of 34% protein and the other half received 18% protein. To make the animals even more susceptible to kidney changes, the researchers removed one kidney.”
At this points he comments that such cruel experimentation was totally unnecessary. I agree with him, sometimes I don’t understand, where is the logic in removing body parts or organs? That has nothing to do with testing real life scenarios.
A little marketing of your own thrown in here and there can’t hurt as long as it is not overwhelming the reader. And in this case, the logic of the Wysong’s Optimal Health Program philosophy would have easily predicted the answers
He then goes on: “The results: six dogs in the 18% protein group died, whereas only one in the 34% group did. Examination of kidney tissue showed no significant difference between the two groups in terms of kidney degeneration or disease. The fact that neither group experienced significant kidney disease, but that the group on the lower protein diet experienced a higher mortality may speaks to the beneficial effects on the immune system of a higher protein diet.
An added finding in this study was that higher dietary levels of phosphorous did not contribute to kidney disease since the diets used in this study were at 0.9% phosphorous, whereas those commercially available for treatment of renal failure are at 0.3% phosphorous.
Moreover, consider that kidney disease in pets fed starch-based processed diets is not seen to any extent in wild animals. Wild animals of all ages consume high protein muscle and organs from their prey. ( DVM (veterinary medical journal), June 1996; page 1S, Dr. D.R. Finco, DVM, PhD, Dip. ACVIM, Head Dept. Physiology and Pharmacology, University of Georgia, College of Veterinary Medicine.
Further evidence regarding the cause and prevention of kidney disease:
1. Protein may not be a factor in slowing the kidney disease progression--
"...Restriction of protein intake does not alter the development of renal lesions nor does it preserve renal function." (See Kirks Veterinary Therapy XIII, Small Animal Practice, W. B. Saunders, page 861). The effect of protein restriction on the progression of renal damage in dogs and cats remains controversial and no definitive study exists on this matter. Not enough protein in the diet can be equally detrimental and protein malnutrition in patients with renal failure can facilitate the occurrence of other complications or lead to an early death. Studies have revealed that protein restriction made no difference at all in longevity. The effect of dietary protein restriction alone on the progression of chronic renal failure is either minimal or non-existent.
2. Ingredients and processing dramatically influence the quality of the protein in mixed processed pet foods. The poorer the quality of the protein and the more it is processed, the more "junk" protein must be excreted by the body putting stress on the kidneys. Studies have shown that there is an inverse relation between the blood urea content and the biological value of the diet. The more meat and organs, and the less they are processed, the less "junk" protein must be excreted by the kidneys. All meat Archetype, Rx Diets, and Treats that have been TNT (true non thermally) processed are of the very highest biological value.”
Note: TNT processing is a process utilized by Wysong in food manufacturing. Without going into too much detail, this is a processing method that does not destroy important raw natural food attributes. The end result looks like a freeze dried product. The advantage is that, unlike with freeze drying, there is no heat involved during processing. You also could call it “cold processing”.
Back to Dr. Wysong:
“3. Chemicals in food (like preservatives, coloring agents, artificial flavoring agents, and the toxins created by processing) and in the environment (contaminated water, air and soil) are directly stressful to the kidneys. These factors are the likely candidates for precipitating kidney disease, not the natural high protein diets carnivores have adapted to over eons.
4. High blood pressure in the kidney deteriorates the organ rapidly. A decrease in blood pressure can thus slow the progression of kidney disease. Studies have shown that supplementation with dietary omega-3 oils provides renoprotective effects in dogs with subtotal nephrectomy. Proteinurea & histologic injury (glomerulus) were less in dogs receiving fish oil. Omega 6 oils, usually in abundance in processed pet foods, are pro inflammatory and increase kidney glomerular pressure and filtration rate. Omega-3s in Wysong Diets and supplements thus can help retard the onset or progression of kidney disease.
5. Probiotic bacteria in the gut hydrolyze urea to ammonia and incorporate it into their own protein. When the bacteria are passed in the feces, along with them go the nitrogenous wastes rather than being absorbed and having to be excreted by the kidneys. Wysong probiotics help facilitate this process.” I don’t know if you feel the same way: Sometimes I don’t know what to believe. If veterinarians are practicing under wrong assumptions, as Dr. Wysong has clearly shown above and underlined with documented backup, what are we supposed to do? What is the “right thing?” It reminds me of my question posted on 09/05/08: “Cats & Dogs with Kidney problems”, which concluded “I understand there are different opinions but it seems to me as if what I found so far just goes from one extreme to the other. Like protein intake if the animal suffers from the disease.” Now after reading Dr. Wysong’s comment, I think we can answer the question of protein intake being related to kidney disease. It appears as if amount of protein being fed has little to do with it. I’m going to keep searching and will bring more opinions here. Because we still don’t know just what exactly defines how much is too much or too little protein.
Previous Blog Comments posted on the topic “Canine Protein Requirements”:
Canine Protein Requirements Part1 Introduction
Canine Protein Requirements Part 2a Definitions
Canine Protein Requirements Part 2b Definitions
Canine Protein Requirements Part 3: Evaluating Protein sources
Canine Protein Requirements Part 4a: Too much or not enough?
Canine Protein Requirements Part 4b: Too much or not enough?