- Not a substitute for professional veterinary help.
Many people assume dogs are carnivores, or meat eaters, due to their origins as meat-loving wolves. Yet while dogs may have eaten mostly meat thousands of years ago, their palates have evolved over time.
Believe it or not, today’s dogs are omnivores, which means they can eat both meat and plants.
We interviewed several pet experts to learn where the idea of dogs as carnivores comes from and what a dog’s anatomy says about their nutritional needs. Read on to get the details, plus learn why the right diet plays such an important role in your dog’s health.
Where Does The Idea Of Dogs As Carnivores Come From?
Dr. Emily Luisana, DVM, DACVIM, a veterinarian and clinical nutritionist at Friendship Hospital for Animals, says there’s a lot of confusion about what the words “carnivore,” “obligate carnivore,“ and “omnivore” mean.
Obligate carnivores, or “true” carnivores, are animals whose diets rely solely on nutrients found in meat.
Omnivores eat both meat and plants as main food sources.
“Being an obligate carnivore would mean that dogs must have meat and can’t process plants, which isn’t true. This line of thinking may lead dog owners to assume an all-meat diet is necessary or healthy,” she explains. “In reality, dogs are omnivores and can eat both meat and plants.”
Cats, on the other hand—er, paw—are obligate carnivores. They require a high-protein diet that includes taurine, an essential amino acid only found in meat, and their systems are unable to adapt to changes in the composition of their diet.
The idea of dogs as carnivores comes from dogs’ history as domesticated wolves, who are also obligate carnivores. However, dogs genetically diverged from wolves 20,000 to 40,000 years ago. Their diets evolved as a result of proximity to human settlements—and the advantage of being able to eat those settlements’ scraps.
In short, the (pretty ancient) history of canine ancestry shouldn’t be the foundation for their modern-day diet and training.
It’s more helpful to think of dogs as omnivores, or as carnivores that require additional nutrient groups on top of protein for a full nutritional profile. Dogs may not always seek out high-protein foods, either. In one 2018 study, some dogs repeatedly chose food that tasted good to them but had less protein than other foods offered.
PK-Photos via iStock
How Do We Know Dogs Are Omnivores?
Dogs’ bodies have adapted to an omnivorous diet over tens of thousands of years. Your dog’s teeth, saliva, stomach, guts, and even poop clearly support this fact.
Teeth
Dogs have sharp canines to tear their food, as well as molars to help them crush and grind plant material.
Stomach
Unlike carnivores and herbivores who tend to eat foods with minimal starch, dogs can digest nearly all carbohydrates they eat.
Intestines
A dog’s small intestine is similar to those of other omnivorous animals: It takes up about 23% of the total gastrointestinal volume. The small intestines of cats and other obligate carnivores are much smaller.
Sense of taste
Dogs may prefer a certain food because of its appearance, odor, flavor, and texture. Additionally, the most common units of a dog’s taste buds responded to amino acids that humans have described as “sweetish.” This is worth noting, as cats and other obligate carnivores don’t have a sweet tooth.
Poop
A recent study on fossilized dog feces found that ancient dogs’ gut microbiome composition showed evidence of an omnivorous diet that included starchy foods.
Modern-day dogs should have a “Goldilocks stool,“ according to Dr. Luisana: “Not too firm, not too soft, and easily picked up.
A few factors that determine stool quality, she says, include:
- Gastrointestinal (GI) bacteria
- Time in the digestive system
- The presence of inflammation
- Food
If your dog’s poop has an unusual consistency or color, Dr. Luisana says high-fiber vegetables and grains may help regulate stool quality and provide fuel for healthy GI flora, or microorganisms in the gut.
Can dogs be vegetarian?
A carefully designed vegan or vegetarian diet may work for your dog. In fact, some canine nutritionists may prescribe this type of diet to treat various health concerns, like pancreatitis or food allergies.
That said, it’s important to get your vet on board before making the change. While a vegan diet can have benefits in some cases, a diet that isn’t nutritionally complete may put your dog at risk of malnutrition, and you’ll want to monitor their health and body condition closely.
AVAVA via iStock
Should Dogs Eat Carbs, Fruits, and Vegetables?
Dr. Luisana says dogs need many essential nutrients, including essential amino acids, essential fatty acids, vitamins, and minerals—and a lot of those can and should come from fruits and vegetables.
“While protein is a wonderful source of some of these nutrients, a meat-only diet will result in deficiencies that can eventually be lethal,” she says. “In addition, there are nutrients that are important but not considered essential, such as phytonutrients and certain antioxidants. Vegetables and fruits can be a wonderful source of these nutrients.”
Alex Schechter, DVM, a veterinarian at Burrwood Veterinary, adds that carbohydrates can be a valuable source of energy, although dogs don’t necessarily need them. According to Schechter, dogs should also eat fiber to support bowel health and promote healthy digestion.
| Nutrient | Daily amount (Dry matter basis) | Ideal food sources |
| Protein | 18%–22% or 5-10 grams per 100 calories | Meat, fish, eggs, soy |
| Fats | 5%–8% or 2–6 grams per 100 calories | Chicken fat, fish and flaxseed oils, coconut oil, beef fat |
| Carbohydrates | 30%–60% or 8–17 grams per 100 calories | Vegetables, fruits, sweet potatoes, millet |
| Fiber | 2%–4% or 0.5–4 grams per 100 calories | Brown rice, whole grain oats, beet pulp, carrots |
So what should you feed your dog? For most, the answer will be a complete and balanced commercial dog food that complies with the American Association of Feed Control Official’s (AAFCO’s) guidelines. A package with an AAFCO statement means the food meets or exceeds their nutrient standards or has completed a feeding trial that aligns with AAFCO guidelines.
But there’s still a lot of variation in AAFCO-approved commercial options, with recipes tailored for a variety of additional health requirements—and that’s a good thing.
As Dr. Luisana points out, it’s important to remember that dogs are all individuals, which is exactly how she treats her patients.
“Each one has different nutritional needs and considerations. For example, some may benefit from a high-protein diet, while others may benefit from a low-protein diet.”
She adds that nutritional requirements may vary by dog breed and size, along with underlying health concerns and dog-to-dog differences.
There’s a diet for nearly all dog needs, including weight loss, sensitive stomach, and high fiber diets. Even if your dog is a picky eater, needs to put on more weight, or prefers fresh ingredients, your vet can help you find the right food.
Some people even try a raw diet, or a diet made up of raw meats, eggs, fruits, and vegetables. Just keep in mind it’s essential to work with a vet when feeding your dog a raw diet—or if you have any concerns about your dog’s dietary needs.
Ultimately, what matters is that your dog is happy, healthy, and eating the right foods for them!
