As in the human practice of veganism, vegan dog foods are those formulated with the exclusion of ingredients that contain or were processed with any part of an animal, or any animal byproduct. Vegan dog food may incorporate the use of fruits, vegetables, cereals, legumes including soya, nuts, vegetable oils, as well as any other non-animal based foods.
The omnivorous domestic dog was originally primarily a carnivore but has evolved to metabolize carbohydrates, fat, and fiber and remain healthy on a diet lower in protein. A systematic review of studies from 2023 found no evidence of detrimental effects of vegetarian diets for dogs; however, the authors pointed out studies tended to have a small sample size, or designs that can be subject to selection bias.
In theory a vegan diet is also nutritionally adequate for dogs if properly formulated and balanced. The American Kennel Club highlights risks factors of a vegan diet such as ensuring adequate protein intake, imbalance of certain amino acids, such as taurine and L-carnitine and potential vitamin or mineral deficiency.<https://www.akc.org/expert-advice/nutrition/dogs-can-adapt-to-a-vegan-diet/ To offset these risks, supplements may need to be added to the dog's vegan or vegetarian diet, most importantly those that provide taurine, L-carnitine and vitamin B-12. According to this advice, dogs in the wild prefer animal-based protein, so matching their diet more closely to what they would eat if getting food on their own is more reliable for ensuring health. This dietary advice for dogs resembles that for humans on balanced vegan diets, where it is also important to ensure inclusion of essential nutrients, such as calcium, iron, iodine, selenium, vitamin B12 and vitamin D, possibly in the form of supplements, especially in pregnancy and early life stages.
Motivations for vegans diets include animal welfare and environmental impacts of animal agriculture. there are around 470 million pet dogs.Nestlé. Winning in PetCare.
History of plant-based dog diets
Plant based dog diets may have been around as early as the Bronze Age. An isotope analysis on a site in the Iberian Peninsula found that one group of dogs had a significant proportion of cereals in their diet. Their isotope patterns scarcely differed from the domestic herbivores pointing to a similar intake of plant protein, though small amounts of animal protein cannot be ruled out this way.
In 1980, the UK's first commercially marketed vegetarian dog food became available.
There are many published vegetarian feeding-regimens available to follow. As the popularity of this diet has grown with a corresponding increase in people practicing vegetarianism, there are various commercial vegetarian and vegan diets available on the market, where both terms are often used interchangeably.
In 2024, a comprehensive feeding trial on one vegan dog diet was successfully completed. Dietary needs of the dog
Dogs will not seek out specific foods to meet nutritional deficiencies and will continue to consume a nutritionally inadequate diet.
The dietary requirements of dogs differ based on a variety of aspects (i.e. age, level of activity, living environment, etc.). Rather than specific ingredients, diets are formulated for their specific nutrients, so every diet prepared must have adequate levels of nutrients, including: protein, fats, carbohydrates, amino acids (methionine, lysine, arginine, etc.), vitamins (B vitamins, vitamin A, etc.), and minerals (calcium, phosphorus, sodium, etc.).
Since dogs are omnivores, they can digest both animal and some plant based matter. A vegetarian diet choice was adapted to canines because of the ethical preferences of people who practice vegetarianism, as well as for pet owners seeking an alternative diet for pets suffering from food allergies, specifically animal-protein allergies.
Potential risks Vegetarian and vegan dog diets may carry some risks, especially when these are homemade.
Alkaline urine High urinary pH is associated with developing struvite crystals, dysuria, hematuria and obstructing the urinary tract of dogs. Breakdown of amino acids has an effect on the acidity of the urine. Plant based diets typically contain fewer of the acidifying amino acids than meat based ones. Studies confirm dogs on plant-based diets have higher pH (i.e. decreased acidity) of their urine. However, it is unclear if this exceeds normal ranges and leads to detrimental clinical outcomes with the limited research available.
With potential increased risk of high pH urine, regular monitoring of a plant-based dogs' urine may provide benefits. When detected early, high urinary pH can be treated by adding more acidifying ingredients or supplements to the diet.
Guidelines A 2020 study evaluated vegan pet foods in the Brazilian market and found nutritional inadequacies when compared to FEDIAF and AAFCO recommendations.
Conversely, a 2019 study analyzing 177 commercial conventional pet foods sold in the UK discovered that most did not meet European guidelines on mineral content, indicating that nutritional deficiencies are not exclusive to plant-based diets.
Homemade diets
Inappropriate nutrient profile There are many vegetarian and vegan recipes available but due to the extra attention creating a complete and balanced plant-based diet requires, many of these are insufficient in macrominerals such as protein, and microminerals that include vitamin D and vitamin B12. These deficiencies cannot be corrected by including specific whole food ingredients due to the volume they would have to eat to meet requirements, thus nutritional supplements are necessary. Supplements contain anywhere from 0–300% of the vitamins and/or mineral amount required daily when the suggested dose is followed. Some ingredient inclusions can also be detrimental to a canine's overall health. Onion and garlic are often included in homemade recipes regardless of their association with hemolytic anemia in dogs. Current recommendations are that all formulations and supplementation of alternative dog diets are made by a veterinary nutritionist.
Deviation from recipe instructions Obtaining precision and accuracy when following a recipe for plant-based diets is essential. Ingredient substitutions made over time due to affordability, availability, and owner and pet preferences, increase the risk of inadequacy. Each ingredient has a specific purpose of inclusion in a recipe; thus, substitutions may not be appropriate, especially if the diet was created for a medical condition. There are many ingredients that have been associated with disease pathologies in dogs and should not be added to a diet. To name a few, raisins, grapes, and sultanas have been associated with renal failure (see Grape toxicity in dogs). Members of the allium family, including onion, garlic, shallots, and leeks are linked to the development of hemolytic anemia, and chocolate is associated with cardiac abnormalities and pancreatitis. A veterinary nutritionist can make suitable suggestions on altering existing recipes if concerns arise.
Inadequate feeding recommendations Feeding instructions for homemade diets often lack clarity. Improper or excluded caloric information and body weight recommendations increase the risk of energy over-consumption leading to obesity. Dogs can also be undernourished and develop deficiency symptoms. Vague feeding guidelines can contribute to poor weight management because ideal body weight values are not communicated to the consumer. Calcium deficiency Commercial vegan diets can result in calcium deficiency, this can result in growth retardation. Skeleton mineralisation accompanied with growth deficiencies result in a decrease of plasma calcium levels and induces hyperparathyroidism, in turn leading to bone resorption. Calcium oxalate urolithiasis High levels of calcium and oxalate in the urine causes urolithiasis. Urinary oxalate is derived from oxalic acid, which is typically occurs only in low volumes in a dog's diet, but vegetables, legumes, and some vegetable-based fibres are high in oxalic acid. Levels of oxalic acid should be below 40–45mg oxalic acid/Mcal or <20 mg oxalic acid/100g of food (dry matter basis). Excessive vitamin C can also cause calcium oxalate urolithiasis.
Potential benefits A systematic review in 2023 reported potential benefits and found little evidence for adverse effects to dogs on a commercial vegetarian diet. Based on dog guardian perceptions, which increase the risk of bias, suggested relatively lower cardiac, skin, and renal issues on vegetarian diets. A benefit for the guardians was less odor from their animals.
Environmental impact Like humans, dogs have a significant environmental impact. In the US, cats and dogs are estimated to be responsible for 25-30% of the impacts from animal farming on the environment. 90% of dogs' impact on carbon emissions comes from the dog food they eat. Switching a dog from a typical diet with meat to one without, reduces those emissions by 37%. The agricultural land freed up if all the world's dogs were fed a vegan diet could feed an additional 450 million people, because animal product require more land than plant-based foods.
On average, switching a dog from a typical to a vegan diet can reduce carbon emissions by 340 kg CO2eq per year.
Processing Processing is an important determinant of what nutrients a dog is actually able to digest and absorb. Plant-based ingredients can be very difficult to break down without proper enzymes in the animal's digestive tract to do this. Processing has the ability to break down nutrients such as insoluble fiber and protein that can aid in the digestibility of the ingredients and ensure the dog is utilizing the nutrients given to meet its requirements. However, processing can cause negative effects to these traits as well.
Processing of kibble – extrusion process
Nutritional aspects of processing Processing has both beneficial and detrimental effects on feed ingredients as it applies high levels of heat, and with extrusion, pressure with reduction of moisture content.
Carbohydrate During the extrusion process, sucrose is converted to reducing sugars that can be lost from Maillard reactions. Therefore, it is often seen that sugar amounts are decreased at this time. Oligosaccharides, such as raffinose and stachyose, impair nutrient utilization of grains. In the extrusion process there is a destruction of oligosaccharides that prevent flatulence and thus improves utilization of legumes used in the feed. Gelatinization of starches is a required step in extruding foods in order to form the desired porous appearance.Pitchon, E. (1980). United States Patent No. 4225630. Flushing, New York:United States Patent Office. This step allows enzymes to react with starch and increase starch breakdown.
Fiber Processing increases water solubility of fiber by reducing the molecular weight of starch molecules like hemicellulose and pectin. This conversion of insoluble to soluble fiber increases the total dietary soluble fiber amounts in the feed mixture by making fiber more susceptible to absorption.
Lipids Levels of 6 to 8% fat used in the extrusion process are not advised, as it limits the product's ability to expand. This is because fat causes poor pressure levels in the barrel due to more traction. If high fat ingredients are used, some free oil may be lost when product goes through the diet. Food processing can increase the nutritional quality of the product by minimizing lipid oxidation.
Vitamins