Lots of dogs eat vegetables. Give most dogs a carrot or a green bean, and they'll be glad to have it. But is it OK to skip meat completely and feed your canine pal a vegetarian diet?
People make decisions about their diets based on various factors ranging from health benefits to cultural, environmental and religious beliefs. Some people pass on those preferences on their pets' diets.
The experts (and by experts, we mean veterinarians) are divided about whether that's a good idea. But to make an informed decision, it helps to look at how science stands on the dog as a carnivore.
The dog as omnivore
There's a long-standing debate over whether dogs are carnivores or omnivores. Carnivores mainly or exclusively have a diet of meat, while omnivores eat meat as well as plants as food.
Dogs belong to the order Carnivora; other species in that group include omnivores such as bears, raccoons and skunks, as well as the giant panda, which is a strict herbivore, points out Cailin Heinze, a board-certified veterinary nutritionist at the Cummings School of Veterinary Medicine at Tufts University.
"From a biological perspective, dogs lack most of the metabolic adaptions to a strict diet of animal flesh that are seen in true carnivores such as cats or ferrets," Heinze writes. "Compared to true carnivores, dogs produce more of the enzymes needed for starch digestion, have much lower protein and amino acid requirements, and can easily utilize vitamin A and D from plant sources, just as people do. We also have evidence that they also evolved from wolves by eating more plant material. All of these factors make them more accurately classified as omnivores than carnivores."
The dog as carnivore
Not all veterinary experts and animal nutritionists are convinced that dogs are omnivores. Veterinarian Patty Khuly writes in Vetstreet about rethinking the "dogma" of dogs as omnivores after hearing a presentation by Dr. Wouter Hendriks at a nutritional conference speaking in favor of canine carnivore-ness.
Included in his many arguments, Hendriks says:
- Dogs’ teeth are adapted to a carnivorous diet (for tearing muscle and crunching bone to extract marrow).
- Many of a dog's natural behaviors are carnivorous in nature. Like wolves, dogs dig to hide parts of meals to eat them later.
- Dogs, like many large mammalian carnivores, are able to survive for long periods of time between meals.
- Dogs have a lot of flexibility in their metabolism to help make up for a feast-or-famine lifestyle. They also have a wide range of possible prey.
Hendriks concludes that dogs are true carnivores with an adaptive metabolism that allows them to successfully eat a grain-based diet, which is the focus of most commercial dog foods.
Creating a meat-free diet
Evolution shows that dogs can live without a strictly meat diet. And if you want to take your dog to the next step and go vegetarian or vegan, that's possible too, say many experts, as long as you do it with care.
Heinze says most dogs can thrive on a well-designed, nutritionally balanced vegan diet. She says she often uses meatless diets with her canine clients when dealing with various health concerns. It's difficult, however, to design these diets. Commercial vegetarian and vegan diets for dogs are not all created equal, she says.
"In general, diets that include eggs or dairy as protein sources are less worrisome than diets based only on plant proteins. Home-prepared diets always fare worse as the vast majority of home-cooked meat-based diets dog owners are feeding lack essential nutrients and the vegetarian and vegan ones typically have all the same deficiencies and then some additional ones, such as protein."
Heinze suggests consulting with a veterinary nutritionist to develop a diet to meet your dog's needs and minimize any potential health risks.
Vegetarian veterinarian Ernie Ward says he feeds his dogs what he calls a "hybrid menu." He cooks vegetarian meals for them a few times a week and then feeds them commercially prepared food (from a bag or can) on the other days.
"At this time, we really don’t have great choices when it comes to vegetarian or vegan diets for dogs," Ward writes in VetStreet. "Sure, you can cook excellent vegetarian meals for your dogs, but it takes more than just time — you also need to commit to learn what will truly give your dog all the nutrients that he needs, and then properly follow through to ensure that he gets them. Without the guidance of a veterinarian, creating a fully balanced diet for your pet can be difficult."
Ward uses non-meat protein sources such as quinoa, rice, lentils, potatoes, soybeans, garbanzo beans, spinach and broccoli when creating his dogs' vegetarian meals.
If you decide to feed a vegetarian or vegan diet to your dog, there are a few more things to consider, suggests WebMD.
- Never feed meat-free diets to puppies or dogs you plan to breed.
- Take your dog to the vet for wellness exams at least twice a year for blood work and checkups.
- Only feed commercial diets that have gone through trials and meet the requirements for AAFCO (Association of American Feed Control Officials) compliance.