Vegetarian dog food? Well, of course! We dispel the dangerous half-knowledge that dogs need meat. Our partner on four paws may have descended from the wolf, but a lot has changed in the centuries alongside humans, especially in the dog's digestive tract. Of course, our pelt-noses need proteins, fats, carbohydrates, minerals and vitamins - but these do not necessarily have to come from animal sources. The modern dog can digest plant food without any problems!
This knowledge does not come by chance, which is why we will give you an overview of scientific studies on the topic of vegetarian dog nutrition and answer the most frequently asked questions in the following article. Don't worry, there will be no long texts with technical terms, because we have summarised the results for you in an easy-to-understand way. Let's go!
My dog is descended from a wolf! Can my dog digest plant-based food ingredients at all?
Evolutionary geneticist Erik Axelsson and his colleagues1 from Uppsala University in Sweden compare the DNA of dogs and wolves in their study, which was published in 2013. The aim was to find out how the genes have changed in the course of the domestication of the dog, alongside humans. To do this, they sequenced the DNA of 12 wolves from around the world and 60 dogs (14 different breeds). The researchers discovered 36 DNA regions with a total of 122 genes that differ from the DNA of wolves and that may have contributed to the evolution of the dog. Ten of these regions are responsible for digesting starch. The digestive enzyme amylase starts the breakdown of starch in the intestine. Compared to the wolf, which has only two copies of a gene for the production of amylase, dogs have between four and 30 copies of this gene. More copies of a gene mean increased production of amylase, which is why this specific genetic mutation enables dogs to digest and metabolise the starch in plant foods far more efficiently than wolves.
In her study, the palaeogeneticist Morgane Ollivier, in collaboration with Axelsson and other scientists2 , found that the increase in the copy number of the starch gene AMY2B already took place 7,000 years ago. For this purpose, ancient DNA was extracted from bones and teeth of 13 wolf and dog specimens found in archaeological sites in Eurasia. According to the scientist, this expansion of the starch genes reflects a local adaptation to early agricultural society. This adaptation gave the dog advantages in living with humans, as it was - and still is - better able to digest starchy food.
In addition to the studies by Axelsson and Ollivier, which focused primarily on the genetics behind starch digestion in dogs, the studies by Murray, Carciofi and Cargo-Froom examined individual feed components in relation to digestibility.
In the 1999 study, Murray and his colleagues3 examined the digestibility of maize, barley, potatoes, rice, millet and wheat in dogs. This was done by feeding six different diets, each with one of these main carbohydrate sources, in an experiment. They found that the digestibility of the starch component in each of these diets was more than 99%. This suggests that the starch was almost completely digested by the dogs. A subsequent study by Carciofi4 in 2008 showed similar results for rice, maize, millet, cassava, brown rice, peas and lentils. The study confirmed that starch digestibility was more than 98%. Although the study by Cargo-Froom5 (2017) does not refer to starch digestion in dogs, this study also gives indications on the digestibility of plant-based feeds. It compared the digestibility of minerals in dogs on meat-based diets with dogs on plant-based diets. Cargo-Froom concluded that the digestibility of endogenous minerals such as phosphorus, magnesium, zinc and manganese in dogs fed a largely plant-based diet was similar to or higher than in dogs fed an animal-based diet. By comparison, the digestibility of meat and meat components, which consist mainly of the ingredients fat and protein, is also only about 98% (Zentek, 20166).
1. Axelsson et al. (2013): Genomic signature of domestication reveals adaptation to a starch-rich diet.
2. Ollivier et al. (2016): AMY2B copy number variation reveals starch diet adaptions in acient European dogs
3. Murray et al. (1999): Evaluation of selected high-starch flours as ingredients in canine diets
4. Carciofi et al. (2008): Auswirkungen von sechs Kohlenhydratquellen auf die Verdaulichkeit von Hundefutter und die postprandiale Glukose- und Insulinreaktion
5. Cargo-Froom et al. (2019): Apparent and actual digestibility of macro- and micronutrients in adult dog diets containing either a majority of animal or plant proteins.
6. Zentek (2016): Nutrition of the dog
Does a vegetarian diet provide my dog with all the important nutrients?
A nutritionally complete and balanced diet ensures adequate intake of fats, carbohydrates, protein, minerals (both bulk and trace) and vitamins to ensure the dog's health and longevity.In his 2016 review, Dr Andrew Knight and Madelaine Leitsberger7 analysed four previous studies on the nutrient tolerance of vegetarian dog foods compared to a meat-based diet. Based on his own data, as well as the growing number of population studies and case reports on the subject, he concluded that dogs can live healthy lives on a vegetarian diet and may even derive health benefits from it, provided a nutritionally complete and balanced diet is fed.
In 2014, Pia-Gloria Semp8 investigated whether dogs also receive all important nutrients on a vegan diet as part of her master's thesis at the University of Veterinary Medicine in Vienna. For her study, 20 dogs that were fed only plant-based diets for a period of at least six months were clinically examined and blood samples were taken. Both the clinical examination and the analysis of the blood samples did not reveal any changes or diseases that could be directly linked to a purely plant-based diet.
7. Knight & Leitsberger (2016): Vegetarian versus Meat-Based Diets for Companion Animals
8. Semp (2014): Vegan nutrition of dogs and cats.
Can a vegetarian diet for my dog have a negative effect on his health?
In 2009, Brown and her colleagues9 studied 12 Siberian huskies that participated in dog sled races. In the 16-week study, six of the 12 huskies were fed a vegetarian diet and the other six were fed a conventional diet with animal ingredients. The study period also included a 10-week period of competitive racing. Blood tests performed during the study showed that the red blood cell count and haemoglobin levels were consistently within the normal range. None of the animals developed anaemia during the study. A consulting veterinarian judged the animals' physical condition to be excellent. Brown concluded that a carefully balanced meat-free diet can maintain normal haematological levels in working dogs.
The study by Pia-Gloria Semp from 20148 as part of her master's thesis at the University of Veterinary Medicine in Vienna has already been used in this article to answer another question. In her study, Semp examined 20 dogs that were fed only plant-based feeds for a period of at least six months. Both the clinical examination and the analysis of the blood samples did not reveal any changes or diseases that could be directly linked to a purely plant-based diet. The parameters examined in the blood of the test dogs did not differ from blood values of dogs fed a conventional diet with animal ingredients.
In her 2019 study, cardiologist Dr Sarah Cavanaugh10 from Ross University's Faculty of Veterinary Medicine examined the amino acid profile in dogs that switched from a conventional meat-based diet to a fully balanced vegan diet. The results showed that the concentration of three-quarters of the amino acids studied (including taurine) in the dogs' blood increased significantly when they were fed a plant-based diet. It therefore concluded that animal ingredients are not necessary for amino acid homeostasis in dogs.
9. Brown et al. (2009): An experimental meat-free diet maintained haematological characteristics in sprint-racing sled dogs
10. Cavanaugh et al. (2019): Amino Acid Concentrations and Echocardiographic Findings in Dogs Fed a Commercial Plant-Based Diet.
Is a vegetarian diet also suitable for dogs with allergies?
Allergies in dogs are most often caused by dietary proteins, less so by carbohydrates or fat (Zentek, 20166). In his 2016 study, Ralph Mueller and colleagues9 investigated food allergies (hypersensitivities and food intolerances) in 297 dogs. They concluded that the most common food allergens causing food reactions in dogs were beef (34%), dairy (17%), chicken (15%) and wheat (13%). Mueller and his colleagues concluded that most of the food allergens for dogs are of animal origin and that a plant-based diet can provide relief for dogs with food allergies and sensitivities.
9. Mueller et al. (2016): Critically appraised topic on adverse food reactions of companion animals (2): common food allergen sources in dogs and cats
The current scientific findings at a glance
Science has been dealing with this topic for a long time and will certainly publish new findings in the future. However, there are already many results that support a vegetarian dog diet:
The increase in the number of copies of the starch gene AMY2B in dogs began as early as 7,000 years ago. Compared to wolves, dogs can therefore digest and metabolise starch in plant foods far more efficiently.
The digestibility of starch components in plant foods is between 98-99%, while the digestibility of meat and meat components is 98%.
As long as the dog is fed a nutritionally complete and balanced diet that ensures adequate intake of fats, carbohydrates, protein, minerals (both bulk and trace elements) and vitamins, it can be fed an optimal vegetarian diet.
Studies that have investigated the health of vegetarian dogs confirm that there is no difference, for example, in blood values compared to animals fed a meat-based diet.
Since most of the food allergens for dogs are of animal origin, a plant-based diet can provide relief.
Science has convinced you? Switch to veggie food now:
The pelt nose does not need meat for a healthy dog's life. Our vegetarian VeggieDog Grainfree and VeggieDog Origin menus - just like all our other varieties - have been developed together with nutritionists according to international nutrient guidelines and therefore provide your four-legged friend with everything he needs.