[Shawna]

laconrad,

Although I do feel small amounts of fresh fruits and vegetables are quite healthy for dogs, carbohydrates aren’t a necessary requirement – even in the modern dog. Yes, when properly processed, they can utilize them but they still aren’t a necessary macronutrient. Waltham is a reliable source of information on this – they state “Cats and dogs can sythesise their own blood glucose from amino acids. Carbohydrate, therefore is not an essential macronutrient. However, if provided in their diet, cats and dogs can utilise carbohydrates and they are used in pet foods as sources of energy and dietary fibre.
Carbohydrate levels tend to be higher in dry pet food than in wet pet food.” https://www.waltham.com/dyn/_assets/_pdfs/waltham-booklets/Essentialcatanddognutritionbookletelectronicversion.pdf

In fact, carbohydrates aren’t even required in complete and balanced foods. There is a minimum protein requirement, a minimum fat requirement but no minimum on carbs. AAFCO guidelines as of 2008 http://www.peteducation.com/article.cfm?c=2+1659&aid=662

They now know that the MINIMUM protein requirement for senior dogs is actually 25%. ” Protein requirements actually increase by about 50% in older dogs, while their energy requirements tend to decrease. When insufficient protein is provided, it can aggravate the age-associated loss of lean body mass and may contribute to earlier mortality. Older dogs should receive at least 25% of their calories from protein, typically provided by diets containing at least 7 g protein/100 Kcal ME.” http://www.ncbi.nlm.nih.gov/pubmed/18656844

It’s also a myth that higher protein amounts have a negative impact on a dog’s kidneys. In fact, dogs WITH kidney disease can safely eat a higher protein diet as long as phosphorus is watched. Here’s my favorite source of info on this “Mythology of Protein Restriction for Dogs with Reduced Renal Function” http://www.championpetfoods.com/wp-content/uploads/2014/12/Myths_of_High_Protein.pdf

The bioavailability of the protein is every bit as important as the overall amount. The more bioavailable the protein the less blood urea nitrogen is created. So the better the quality of the protein the more that can be fed. An ounce of protein from beef, as an example, will be better utilized, leaving less waste, than an ounce of soy protein. Additionally raw protein will be better utilized then it’s cooked counterpart due to amino acid loss lowering bioavailability.

I have never read any literature suggesting protein as a cause of cirrhosis however I would agree that lowering protein would be advised if the liver is already severely damaged. NOT because the protein is further “damaging” the liver however the ammonia not being converted is quite toxic. Even in this article relating to humans they don’t suggest excess dietary protein as a cause https://www.nlm.nih.gov/medlineplus/ency/article/000302.htm

Excess fiber in the diet has been shown to act as an anti-nutrient. I just this week read a research paper on this but I bookmarked it at work and don’t have access right now.

You’ve mentioned the liver and kidneys several times so I thought I’d add a little more research on the kidneys. “Long-term renal responses to high dietary protein in dogs with 75% nephrectomy. 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.” http://www.ncbi.nlm.nih.gov/pubmed/3702209

Purina Veterinary Diets
“A University of Minnesota study revealed renal aging does not occur in geriatric dogs, at least to the extent that it has been reported in people. When fed a diet of 39% protein and 15% fat (dry matter basis), geriatric dogs maintained relatively stable glomerular filtration rates and had no greater incidence of glomerulosclerosis than those dogs in the protein-restricted (19% dry matter basis) diet group. These and other studies indicate no need for restricted dietary protein, fat, sodium or phosphorus to help minimize renal disease progression in healthy geriatric dogs. Still other studies have shown high dietary protein alone will not cause the development of kidney disease. In addition, research has shown that older dogs may actually require more protein than younger adult dogs, just to maintain normal protein turnover, and to support lean body mass and normal immunocompetence.

Obesity has been associated with arthritis, cardiovascular disease, diabetes mellitus, neoplasia and decreased survival. Therefore, efforts to maintain ideal body weight and body condition are far more important and appropriate than protein or phosphorus reduction for maintaining health in geriatric dogs.” https://www.purinaveterinarydiets.com/research/senior-dogs-do-old-kidneys-need-new-diets/

Interestingly, at least two papers published in the Journal of Nutrition have shown higher protein diets to be beneficial for weight loss in dogs.

“High-Protein Low-Carbohydrate Diets Enhance Weight Loss in Dogs” http://jn.nutrition.org/content/134/8/2087S.full

“Weight Loss in Obese Dogs: Evaluation of a High-Protein, Low-Carbohydrate Diet” http://jn.nutrition.org/content/132/6/1685S.full