According to present research, all of the essential nutrients for dogs (proteins, fats, minerals, vitamins, etc.) can be obtained from nonanimal sources.13 Since no single ingredient contains all essential nutrients in sufficient quantities or proportions, plant-based products must be carefully designed to ensure a well-balanced and nutritionally complete diet.13 In this blog post, we will take a look at some common ingredients in plant-based dog food and examine how they meet nutritional requirements of dogs.
Plants are an excellent source of essential nutrients
According to the Association of American Feed Control Officials (AAFCO), dogs require at least 20% protein content in their food. This protein requirement is easily fulfilled by addition of high-protein plants as main ingredients in dog food (soybean meal, corn gluten meal, peas, etc). Many research studies demonstrated validity and excellent value of these ingredients for dog nutrition.2 In fact, it was found that amino-acid profile of soy is comparable to that of meat, and all essential amino acids for dogs can be obtained from a combination of soy with other plant ingredients. Peas, lentils and other high-protein plants are also good protein sources for dogs, with a balanced profile of digestible amino acids.2 Unlike animal protein, plant proteins are not common allergens and have not been associated with negative reactions in dogs.2
Plant Ingredients in the Stomach – Digestibility
A good food ingredient has to provide essential nutrients and be easily digested in a dog’s stomach. Dozens of digestibility experiments have been conducted with dogs in many research institutions, which demonstrated that plant ingredients have high digestibility rankings. In other words, digestive systems of dogs easily derive essential nutrients from plant ingredients.
In several experiments 6,9,10, groups of dogs were fed diets with different grain sources (rice, oats, corn, sorghum, peas, barley or lentils) and digestibilities of these ingredients were measured. All these experiments recorded very high digestibility values (>98%) for all grains – that is, dogs absorbed almost all essential nutrients from these grains. Digestibility indices were the highest for rice, oats, corn and soy, and slightly lower for peas, lentils and potatoes. Investigators concluded that all studied ingredients are excellent sources of easily digestible nutrients and should be included in canine diets.6,9,10
These results are confirmed by another similar study which measured digestibility of 21 plants in dogs. This study reported high digestibility rankings for soya protein, soya meal, soya flours, wheat, barley, corn oat meal, wheat‐germ meal and other plant products commonly used in dog foods (digestibility values 0.72 - 0.96).13
Dogs digest grains better than some common animal-based ingredients. A recent experiment in France12 compared digestibility values of wheat-based vs. poultry-based diets for dogs, by feeding 27 dogs a diet which included either wheat gluten, poultry meal, or a 50:50 mixture of both. Overall digestibility score was higher for wheat gluten than poultry meal, which demonstrates that wheat gluten is an excellent ingredient in plant-based foods for dogs.12
Complex carbohydrates are not fully digested and have lower digestibility indices. It has been demonstrated that that non-digestible carbohydrates are beneficial for gut health of dogs and should be included in a dog's diet.8 Complex carbohydrates are present in whole grains, vegetables and other common plant ingredients.
Inclusion of enzymes has a beneficial effect on absorption of nutrients. In a recent study7, dogs were fed diets based on soybean meal, with or without inclusion of enzymes. These dogs clearly preferred diets with enzymes included, and enzyme-containing diets were better digestible (i.e. displayed higher digestibility ratings) than the ones that did not contain enzymes.7 Please refer to our ProZyme product page for more information on digestive enzymes for dogs.
Digestibility of supplemented minerals was measured in a recent study at the University of Guelph. 3 In this dietary experiment, two groups of Beagles were fed either a meat-based diet or a vegetable-based diet, both supplemented with essential minerals (potassium, copper, zinc, calcium, iron, etc.). It was found that digestibility of minerals was high in both groups, and there were no differences in digestibility values of most minerals studied. In addition, dogs in vegetable-based dietary group showed higher digestibility of calcium and iron, compared to dogs fed meat-based diet.3 This important research shows that plant-based diets can be safely supplemented with essential minerals to fulfill nutritional requirements of dogs.13
Plant Ingredients + Supplementation = Well-Balanced, Healthy Formula
Both animal-based and plant-based formulas rely on supplemented nutrients to be nutritionally complete.13 Most vitamins required by dogs are readily available in plant-based ingredients, and some are supplemented to provide complete nutrition.
Vitamin A requirement is achieved by addition of vegetables that contain precursor provitamin A carotenoids, which dogs can metabolize to form active vitamin A. Carotenoids are present in red, yellow, green and orange vegetables that are added to plant-based dog food. Synthetic vitamin A analog, in the form of retinyl esters, is also added to plant-based diets.13
Vitamin B complex includes a number of essential nutrients, such as thiamine (vitamin B1), riboflavin (vitamin B2), niacin (vitamin B3), pantothenic acid (vitamin B5), pyridoxine (vitamin B6), biotin (vitamin B7), folate (vitamin B9), and cobalamin (vitamin B12). All vitamins in the B-group are readily available in plant sources, except cobalamin (vitamin B12).13 Therefore, all plant-based dog formulas are supplemented with vitamin B12.
Cats and dogs (unlike rats and other herbivores) do not convert UV rays to vitamin D and so they need to receive it in their diet.5 Vitamin D can be sourced in two ways: by addition of microalgae, which contains both vitamin D3 and provitamin D3, or by derivation of vitamin D2 from fungi and yeasts from UVB-exposure of provitamin D2.13, 14
Healthy plant ingredients are combined with supplemented vitamins and minerals in plant-based food laboratories. The result is well-balanced and nutritionally complete formulas that conform to AAFCO and FEDIAF nutritional guidelines for dogs. Please see which plant ingredients make up our healthy products, in the next section.
Ingredients in Vecado products
Prozyme contains enzymes beneficial for digestion.