Hi 2nd2none –
The idea that only active dogs require more protein is a myth. In fact, strenuous activity has only a marginal impact on dietary protein requirements.
From “Basic Animal Nutrition and Feeding” 5th Ed.:
“Rennie and Tipton (2000), in a review of this subject [the effect of strenuous exercise on protein and amino acid metabolism], reported that sustained exercise stimulates amino acid oxidation (chiefly branched chain) for gluconeogenesis and possibly affects regulation of acid-base balance, resulting in a short-term net loss of tissue protein due to decreased synthesis and increased degradation. Protein synthesis rebounds quickly following rest. The data indicate that exercise does not increase the dietary protein requirement; in fact, efficiency of protein metabolism may be improved as a result of exercise.”
Higher protein does not equate to more calories when in fact the opposite is true. Protein contains 4 kcal. per gram, carbohydrates contain 4 kcal. per gram and fat contains 9 kcal. per gram. Exchanging carbohydrate for protein does not change the caloric density of the food and exchanging fat with protein would actually decrease the caloric density of the food.
From “Focusing on Protein in the Diet” by T.J. Dunn Jr. DVM:
“Extra carbohydrate intake, above the immediate needs of the dog (which occurs often with grain-based diets) prompts internal enzyme factors to store that extra carbohydrate (sugar) as fat. Give that same dog extra protein and it is excreted through the kidneys and NOT stored as fat. Knowing this, what do you think would make a better “weight loss diet” for a dog … one with grain as the main ingredient or one with a protein-rich meat source as the main ingredient?”
It’s also a myth that excess protein (beyond what is necessary to meet the dog’s amino acid requirements) harms the kidneys. It is the job of the kidneys to excrete wastes and in a healthy animal, the kidneys are fully able to do this.
From “Small Animal Clinical Nutrition” 4th ed.:
“Feeding protein above requirements or recommendations for healthy dogs and cats does not result in toxicity because the excess amino acids from the protein are catabolized and the waste nitrogen is excreted.”
From “Focusing on Protein in the Diet” by T.J. Dunn Jr. DVM:
“The very early research that pointed a finger at protein as being a cause of kidney failure in dogs wasn’t even done on dogs! It was done on rats fed unnatural diets for a rodent — diets high in protein. (Were we tinkering with Nature during these ātestsā?) Rats have difficulty excreting excess protein in their diets because they are essentially plant eaters, not meat eaters. Dogs are quite able to tolerate diets with protein levels higher than 30 percent on a dry weight basis. Dogs are meat eaters; that’s how Nature made them!”
From “Kirk’s Veterinary Therapy XIII, Small Animal Practice” p. 861:
“…restriction of protein intake does not alter the development of renal lesions nor does it preserve renal function. Considering these (research) findings, the authors do not recommend reduction of dietary protein in dogs with renal disease or reduced renal function in order to achieve renoprotective effects.”
