Can Dogs Be Plant-Based? Here’s What The Science Says

Dogs need specific nutrients to be healthy, and they needn’t come from animals

BY CLAIRE HAMLETT 19th january 2024

There are lots of reasons you might be considering putting your dog on a plant-based diet. If you’re vegan, then you might be ethically conflicted about feeding other animals to your companion.

If you’re worried about the climate crisis, then turning your dog plant-based is certainly one way to cut your personal emissions. Research shows that if all dogs went vegan, the emissions savings would be equivalent to those produced by the UK.

At the same time, you want the best for your dog. The pet food industry has long made meaty meals look like the only option for our canine companions. But is that really the case? Can dogs be healthy – and happy – on a plant-based diet?

To help you make an informed decision, here is everything you need to know about plant-based diets for dogs.

Dog nutrition

A healthy diet for dogs is a balance of proteins, fats, fiber, minerals, and vitamins. There are 10 amino acids for building protein that a dog’s body can’t produce itself. Instead these need to come from food. The diet of an adult dog should be minimum 18 percent protein. Protein content should not exceed 30 percent as too much can put stress on the kidneys.

Dogs need a particular balance of saturated and unsaturated fats to provide energy. These protect the nervous system and help ensure healthy skin and fur. Unsaturated fatty acids like omega 3 and 6 are important. A ratio of approximately 4-1 omega 6 to omega 3 is best for dogs. Many commercial dog foods get the ratio wrong, resulting in too little omega 3 and too much omega 6. This causes inflammation.

Vitamins A, D, and various B vitamins are among those important for a dog’s health. In addition, they need both macrominerals and microminerals. The former include calcium, phosphorous, and sulfur. The latter include iron, zinc, and copper.

Fiber is important for good digestive function and is provided through carbohydrates, which also provide a lot of energy for dogs. While grain-free diets for dogs have become popular, dogs have evolved to be able to digest starchy carbohydrates like grains and potatoes. But too much fiber is bad, as it stops dogs digesting nutrients properly.

Can plant foods provide all the nutrients dogs need?

A dog’s dietary needs depend on factors like age and activity levels

Andrew Knight, a veterinary professor of animal welfare, is one expert who strongly believes dogs can be plant-based with the right nutrition. “Provided the diet has been produced by a reputable pet food company, and is nutritionally-sound,” he tells Plant Based News (PBN).

Ensuring a dog gets sufficient protein and particular vitamins and minerals is the main source of concern around feeding dogs plant-based diets.

The digestibility and bioavailability of these nutrients is important to make sure your dog is getting enough of them. The bioavailability of a nutrient in food is determined by how much of it is absorbed and used by the body.

Plant proteins

When it comes to protein, dogs can get all the necessary amino acids from a mix of animal and plant sources or from plant sources alone. Legumes like soy and grains can provide most of them. Peanuts, seeds like flaxseed, and certain vegetables such as potatoes can provide the rest.

But are plants sources of protein equal to animal sources for dogs? Levels of amino acids including leucine, isoleucine, and valine are sufficient in plant foods such as soy and grains. But these plants are more limited in other amino acids such as lysine. Dog food can be fortified with additional plant-based supplements to cover all the protein bases.

Taurine is one amino acid that’s good for dogs (and essential for cats) that is very difficult to get from plants. But a dog’s body can synthesize it from the amino acids methionine and cysteine. These can be found in plant sources and supplemented in dog food.

Just because there is variability in protein quality between animal and plant sources doesn’t mean animal-based diets are automatically better. Factors such as processing can reduce or enhancedigestibility of animal and plant proteins. So can the level of dietary fiber in a diet. The size, breed, activity levels, and age of a dog should also be considered when choosing the right diet to support their health.

Plant fats

Omega fatty acids do not come exclusively from fishes, despite common assumptions. Seeds such as flax and hemp are good sources of both omega 3 and 6. Marine algae oil and phytoplankton can provide dogs with omega 3 as well.

Plant minerals and vitamins

All the necessary minerals and vitamins are available in plant foods that dogs can eat. This is a pretty useful list of the animal and plant sources of each, except that it mistakenly does not include plant sources for vitamin D and phosphorus.

Vitamin D can be obtained from mushrooms (dogs can eat the same ones as humans) as well as supplements. Phosphorus is found in nuts, wholegrains, and seeds.

What does the science say

Over the last few years, there has been a good amount of research on the issue of dog plant-based diets, with much of it finding positive outcomes. “There are now 10 studies showing equivalent or superior health outcomes for dogs fed vegan diets, says Knight. “One of the most recent showed that dogs fed vegan diets lived 1.5 years longer, on average. This equates to a human living about an extra decade. And these dogs are not just living longer, they’re enjoying better quality of life as well. Multiple studies have shown benefits such as reduction in itchy skin and obesity, and better mobility, associated with nutritionally-sound vegan diets.”

In a 2023 review of the evidence, researchers found that there is scarce evidence to show negative health effects in dogs fed vegan diets. Some studies also contradicted those showing evidence of adverse health impacts. The authors of the review warn that “given the lack of large population-based studies, a cautious approach is recommended. If guardians wish to implement a vegan diet, it is recommended that commercial foods are used.”

In a paper for the Journal of the American Medical Veterinary Association, veterinary researchers note that dogs need specific nutrients, but there is no requirement that these come from animal sources. They concluded that dietary needs can be met from plant sources alone, with supplements added to food as necessary.

One large-scale study on guardian-reported indicators of health found that vegan dogs fared better than dogs fed conventional meat diets. Dogs fed on raw animal-based diets fared slightly better than the vegan dogs, though they tended to be younger, which is known to improve health outcomes. The researchers acknowledged that guardians could have unconscious bias in their reporting on their dogs’ health.

Two other positive studies were a Master’s thesis. One found that vegan dogs had fewer nutrient deficiencies than meat-fed dogs. The other found that dogs fed an exclusively vegan diet for at least six months showed no nutritional deficiencies and no disease that could be attributed to the diet. Homemade diets were found to be deficient in some nutrients – but that is often true of all homemade food for companion animals. Both theses were based on blood samples in addition to guardian-reported data.

According to another study, yeast and legumes are safe sources of protein for dogs. In a feeding trial, dogs fed on plant proteins had healthy poop and the proteins were found to be highly digestible. There was no particular difference for dogs fed on chicken protein.

One study found that pulse-based diets are beneficial for lowering dogs’ blood sugar. But these diets resulted in decreased macronutrient and amino acid digestibility after just seven days. However, this study was concerned with the removal of grains from dogs’ diets and their replacement with pulses. The conclusion does not therefore show that plant-based diets are unhealthy, but that pulse-based grain-free ones are likely to be unhealthy.

The most recent study, from the University of Illinois, found that dogs fed commercial vegan diets “performed well” for digestibility along the whole digestive tract compared to chicken-based food.

What do vets say?

Vets are divided on whether dogs can be healthy on plant-based diets. The British Veterinary Association had previously not endorsed vegan diets for dogs. But following publication of the Illionis study, it set up a working group to reassess its position in May 2023.

As vegan dog food is not a mainstream choice, it may be hard to find a vet who is particularly knowledgeable about it. But most plant-based dog food brands develop their food with the input of vets.

The reality of meat dog food

Critics of plant-based dog food often don’t take into account the shortfalls of traditional animal-based dog food, which is often made from low quality meat and highly supplemented (not part of the “natural” dog diet that it’s proponents often label it as).

“Meat-based pet foods are nearly 50 percent plant-material, combined with animal products (including poor quality ingredients and byproducts), heavily supplemented with amino acids, vitamins, minerals, and non-nutritive additives (preservatives, flavourants and colourants),” says Knight. “The amino acids and vitamins need adding as naturally-occurring ones are degraded or destroyed by high temperatures, pressures and chemical treatments during processing.”

According to Knight, vegan pet foods are made along the same lines, but without the poor quality animal ingredients. “Hence, no food intolerance/allergic reactions to these, so lowered rates of itchy skin, ear canal problems, and gastrointestinal problems, and with more of the plant-based ingredients,” he says.

What plant-based dog food brands are healthy

The Association of American Feed Control Officials(AAFCO) and FEDIAF Euoprean Pet Food have developed nutrient profiles for dogs and other companion animals for the pet food industry to follow. These ensure nutritional adequacy of commercial food throughout animals’ lives.

Wild Earth is a popular plant-based dog food manufacturer. Its ingredients cover all the essential protein (with a minimum of 23 percent), fatty acid, and mineral and vitamin needs of dogs. It exceeds AAFCO guidelines, which don’t include omegas 3 and 6 as essential. Barley, brown rice, sorghum, yeast, and potato protein are among the main ingredients in Wild Earth’s kibble. Wild Earth food is also supplemented with nutrients such as taurine and vitamin D2.

V-Dog has similar main ingredients, with the addition of pea protein (24 percent). Its products meet AAFCO standards. It adds some vitamin and minerals to the food.

UK brand Omni is quite high in protein at 30 percent. It comes from potatoes, pea starch, soya, brown rice, and yeasts. Omni supplements various minerals and vitamins including amino acids taurine and methionine. It meets nutrition standards set by FEDIAF.

Do dogs like plant-based food?

Some dogs gobble anything you put in front of them, and plenty you’d rather they wouldn’t eat. Others can be picky about their food. There is no guarantee they will like plant-based meals. But there are lots of brands to try offering different flavors. Most now produce wet food as well as kibble. This makes it even easier to test out different foods until you hit on the one that makes their tail wag.

Judging by reviews of plant-based dog food websites, many dogs really love their vegan food. Guardians often seem to turn to it after finding their dog has stomach issues from eating meat or that animal products give them allergies. Many claim that plant-based food solves these problems.

Famous plant-based dogs

Bramble, a Border Collie from the UK, is probably one of the most well-known plant-based dogs. She lived for 25 years – nearly double the average lifespan of Border Collies.

Formula 1 racer Lewis Hamilton, famously vegan himself, has fed his dog a vegan diet since at least 2020. He has praised plant-based food with improving the health of Roscoe, a British Bulldog.

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We humans are obsessed with the latest superfoods — and rightfully so. Some of those snacks pack a major punch, and in a world of preservatives and confusing marketing, there’s no harm in wanting to stick to the classics. But what are the vitamin and mineral equivalents of turmeric for dogs? Because we for sure want to be feeding them to our pups.

“Functional superfoods [have] the most beneficial effects on health,” Dr. W. Jean Dodds says. “They reduce chronic inflammation and promote healing; are powerfully antioxidant, antimicrobial and antitumor; and are even believed to delay aging.” Serving your dog the vitamins and minerals in these essential canine functional superfoods will help your dog fight disease, boost energy, and maintain good health and weight in general.

So, what vitamins do dogs need every day and what foods do they come from? For some pet parents, feeding dogs commercial food makes the most sense; it is not only convenient, but — if they select high-quality food made by companies with proven records of ingredient integrity — it provides their dogs with a generally wholesome diet. But there are a lot of factors in commercial pet food to consider.

Below are vitamins and minerals your pup needs, plus how you can add them to your dog’s diet with superfoods.

Vitamins

Vitamin A

Carrots, spinach, liver, pumpkin, sweet potatoes, fish oil, eggs, and turnip greens.

Vitamin D

Marine fish oil, fatty fish, egg yolks, dairy products, liver, beef, and cottage cheese.

Vitamin E

Plant oils, leafy green vegetables, seeds, wheat germ, bran, whole grains, and liver.

Vitamin K

Liver, leafy green vegetables, milk, cabbage, and fish.

Vitamin C

Fruits, vegetables, and organ meats.

Vitamin B

Whole grains, nutritional or brewers yeast, liver, beans, green vegetables, spirulina, nuts, and dairy products.

Macrominerals

Calcium

Milk, yogurt, tofu, sardines with bones, raw bones, bok choy, green beans, broccoli, and cauliflower.

Phosphorous

All animal tissues, eggs, fish, and milk.

Magnesium

Spinach, broccoli, green beans, tofu, tomato juice, beans, whole grains, and seafood.

Potassium, sodium and chloride

Fruits, vegetables, milk, and grain.

Microminerals

Zinc

Spinach, broccoli, yogurt, beef, poultry, whole grains, and vegetables.

Sulfur

All protein foods (meats, fish, poultry, eggs, legumes, and milk).

Iron

Red meats, fish, poultry, shellfish, eggs, and legumes.

Iodine

Iodized salt, seafood, dairy products, and kelp.

Selenium

Seafood, meat, whole grains, brown rice, and vegetables.

Copper

Seafood, nuts, whole grains, seeds, and legumes.

Manganese

Nuts, whole grains, and leafy vegetables.

Chromium

Lean meat, vegetable oils, and brewers yeast.

Cobalt

Liver, kidney, fruit, and vegetables.

Fluorine

Water.

Molybdenum

Legumes, cereals, and organ meats.

Silicon

Cereals, vegetables, beans, and peas.