Are Dogs Omnivores or Carnivores?
Are dogs omnivorous or carnivorous? This question generates some debate. Many experts say dogs are omnivores since they can eat and digest both animal and plant foods. But other experts point out that dogs descended from wolves, an animal classified as a true carnivore — or an obligate carnivore — meaning they depend on meat for survival.
These contrasting views can make it challenging for pet parents to know how to feed their dogs. But there’s one thing most experts agree upon: you can generally keep dogs healthy as long as you ensure they get all the nutrients they require, and there are different ways to do so.
Read on for more information about canine nutrition and to see if we can officially answer the question: are dogs omnivores or carnivores?
Dog Nutritional Requirements: A Closer Look
What does a dog need to eat to stay healthy?
According to the Association of American Feed Control Officials (AAFCO), an organization that stipulates nutritional standards for pet food, dogs need proteins and fats, as well as a range of minerals and vitamins, including potassium, magnesium, zinc, iron, choline, vitamin D, vitamin E, vitamin K, vitamin A, and various B vitamins.
Although many dog diets are high in carbohydrates, some debate exists about whether dogs need to eat carbs.
“While it can’t be denied that dogs have no biological need for carbohydrates, I would argue that they should still form part of their diet for the benefits they provide,” says Gerald Pepin, a canine nutritionist in the U.K. who professionally advises pet parents about how to keep their dogs healthy with homemade meals. Pepin also believes it’s better to feed homemade dog food rather than commercially produced food, which he says is full of “simple carbs rather than complex-carbohydrates.”
Veterinarians and veterinary nutritionists, however, often caution owners that home-cooked meals could be nutrient deficient if not prepared correctly. Commercial diets are specifically formulated to meet all of a dog’s nutritional needs.
Also, while most experts promote meat-based diets in dogs, some individuals say it is better to feed your dog a vegan or vegetarian diet.
To know what’s best for dogs, it helps to understand their evolutionary biology.
Are Dogs Omnivores?
Many experts would say yes. “Dogs are, without a doubt, omnivores,” says Pepin, explaining that this is because gray wolves (the dog’s ancestor) ate some plant material as part of their diet, usually from the stomach contents of their prey. “The biggest difference between the wolf and today’s domestic dog is that the dog has undergone genetic changes to allow it to benefit from a wider range of plant material than the wolf.”
Andrew Knight, a veterinary professor at Winchester University in the U.K., agrees that dogs are omnivores. He says that dogs’ omnivorous qualities fully developed when they began to live alongside humans about 30,000 years ago.
“Dogs certainly accompanied hunting parties and ate scraps of meat, but actually the primary diet that our ancestors survived on was cooked starchy root vegetables,” he says. “And the dogs that developed adaptations in order to get nutritional benefits from all of those food scraps were the ones that did better.” For instance, he notes how dogs have developed enzymes that allow them to digest starch — a trait that true carnivores lack.
Experts say that dogs can eat and digest plant-based foods and draw all of their nutritional needs from these foods. Some studies have even shown that dogs on vegan diets have increased longevity and fewer health problems. For instance, a study led by Knight himself compared conventional meat, raw meat, and vegan diets for dogs and found that vegan diets were the most “nutritiously sound” and “least hazardous” for dogs [1].
“Not only are [vegan dogs] living longer, but they’re actually living better,” Knight explains. “There are a couple of consistent benefits that come out across most of the studies … one is less itchy skin, ear canal problems, and gastrointestinal reactions. I think these could be related to a lack of dietary allergens that we know are in some meat-based sources like beef, lamb, chicken.” A second benefit is that dogs on a vegan diet are less obese and have fewer musculoskeletal problems and mobility problems, which Knight attributes to a lack of “overnutrition” that can occur when a dog is on a strictly meat-based diet.
Pepin agrees that plant-based diets are not only doable but healthy. “While many would disagree with allowing a dog to be vegan, it is not only possible, it can, in fact, be a healthier option for some dogs,” he elaborates. “It may surprise some people to learn that some of the longest-ever lived dogs have been fed a vegetarian diet.” However, he says a vegan diet requires “more careful management than if a dog is fed an animal-protein based diet.”
Are Dogs Carnivores?
With so much evidence that dogs can eat plant-based foods, does this definitely make dogs omnivorous? Or are they actually carnivores?
Guido Bosch, an assistant professor of animal nutrition at Wageningen University, the Netherlands, says the answer depends on how you look at it. “From a genetic point of view, dogs can still interbreed with wolves; they are actually a sub-species of the wolf,” he notes. “With domestication, the diet changed. A wolf is really a carnivore [2], but throughout domestication, the dog changed from a diet that is more animal-based to a more omnivore type of diet.”
While domesticated dogs have the genetic markers of an omnivorous diet, such as their ability to digest starch, Bosch says that dogs still share many traits with wolves that suggest that they are meant to eat meat. For instance, he explains that dogs will bury their food, a behavior wolves display when coping with periods of famine. Regarding biological characteristics, dogs have short intestinal tracts that allow them to process meat quickly and teeth designed for eating prey.
“They have flat molars like we have, but we can move our jaws sideways,” says Bosch. “Dogs cannot do that — they have more like a scissor-type jaw, so it’s used more for breaking large bones to get access to the marrow.”
Pepin mentions that while there is no denying that dogs’ teeth and digestive systems are designed to “eat meat as a first-choice option,” dogs have changed considerably, undergoing genetic shifts that have allowed them to benefit from the same diet as humans. “Dogs are, in fact, opportunist carnivores,” he elaborates. “That is to say, they will eat meat generally as a preference if given the choice. But if meat is not available, they will happily thrive on plant-based protein instead.”
“Don’t forget, in many parts of the world, animal proteins are scarce,” Pepin adds. “In particularly agrarian parts of the world, dogs and humans have always eaten, and continue to eat, a mainly plant-based diet. The Aztecs, for example, loved their dogs. But because they themselves ate a largely plant-based diet, so did their dogs. And just to prove a point, their beloved Chihuahua is still with us today, all these hundreds of years later!”
Are Dogs Omnivores or Carnivores? The Verdict
As it turns out, the answer to this question isn’t 100 percent clear cut.
Most domesticated dogs today eat omnivorous diets, and their bodies are designed to draw nutrition from plant-based foods. This suggests that dogs are omnivores. However, when we consider that dogs directly descended from carnivorous wolves, it makes us wonder if dogs are carnivores.
Bosch says he likes to avoid categorizing dogs as either omnivorous or carnivorous.
“I don’t really see the relevance of classifying dogs as an omnivore or a carnivore,” he notes. “Just make sure that you meet the nutrient requirements, and that’s the best thing that we can do at this moment.”
If you’re feeling confused about what to ultimately feed your dog, Pepin suggests speaking to an expert. “I would advise any pet parent to seek the advice of a dog nutritionist,” he recommends. “Most pet parents wait until their dog becomes ill before questioning the role of diet in its health. Diet is everything. It has been estimated that up to 80 percent of canine health problems could be cured purely with an improved diet. And this can only be achieved by a dog nutritionist, someone trained in the specifics of canine nutrition.”
Knight also warns against falling for fads like raw meat diets for dogs, which he says can lead to nutritional deficiencies and imbalances. Not only that, but research has shown that raw meat diets can contaminate both dogs and their pet parents with dangerous pathogens and bacteria [3].
Like Pepin, Knight’s advice is to consult an expert or seek out commercially produced foods proven to be nutritionally wholesome. In short, he says to do whatever you can to “ensure your dog’s diet is nutritionally sound.”
References
- Knight, Andrew et al. “Vegan versus meat-based dog food: Guardian-reported indicators of health.” PloS one vol. 17,4 e0265662. 13 Apr. 2022, doi:10.1371/journal.pone.0265662
- Bosch, Guido et al. “Dietary nutrient profiles of wild wolves: insights for optimal dog nutrition?.” The British journal of nutrition vol. 113 Suppl (2015): S40-54. doi:10.1017/S0007114514002311
- Nüesch-Inderbinen, Magdalena & Treier, Andrea & Zurfluh, Katrin & Stephan, Roger. (2019). Raw meat-based diets for companion animals: a potential source of transmission of pathogenic and antimicrobial-resistant Enterobacteriaceae. Royal Society Open Science. 6. 191170. 10.1098/rsos.191170.
