If you are eating plant-based meals and have wondered about similar options for your fur baby, you're not alone, but experts say you need to be careful to choose vegan dog food or vegetarian dog food that's healthy.

With more people eating plant proteins, searches on Google for “vegan dog food” were up more than 77% in August in the U.S. versus four years earlier, according to data from Google. It's a dietary switch that can have a big impact.

After all, the amount of food made from animals and for animals—for cats and dogs—is about 20% of the total eaten by humans in our country, according to an analysis out of the University of California at Los Angeles. That translates to our pets having an impact on both animal welfare and the environment, given that growing animals for food is one of the biggest causes of global warming.

Plant-based pet food, on the other hand, is kinder to Mother Nature, and there are some formulas of vegan dog food that satisfy vets. Like humans, dogs are omnivores and can survive on either plants or animals. Cats, on the other hand, are full carnivores and need meat.

“A vegetarian diet can be an appropriate feeding choice for a healthy adult dog, assuming it is complete and balanced and manufactured by a reputable company,” said veterinarian Jennifer Larsen who focuses her research on animal nutrition and has studied plant-based diets as a professor at U.C. Davis.

It's worth noting that there has been less research on animal nutrition, vegan animal nutrition and vegetarian animal nutrition than there has been on human needs, and those needs are different. Ask your vet for more advice on feeding dogs.

Purina HA Vegetarian and Royal Canin Vegetarian Dog Food are Top Picks

Enzo sitting with Royal Canan vegetarian dog food

Larsen and other vets, including some that work with my family, recommend either Purina Pro Plan Veterinarian Diets HA dry, which comes in a vegetarian version with soy protein, or Royal Canin Vegetarian Dog food, dry or canned, with potato protein.

Both foods are marketed and prescribed for animals who have trouble digesting meat. If you order the food online, the retailer will call your vet.

The major ingredients of both are vegan, but they also contain a mix of vitamin supplements that, to be honest, may be derived from animals. So they are vegetarian, but the manufacturers would have to force their suppliers to certify that they are providing the vegan versions of the vitamins. That will depend on consumer demand for vegan dog food over time.

It's a shame to look for a plant-based food and to have to call it “almost vegan,” but for me it is a step forward. So far Enzo has tried the Royal Canin version and loves it, and it gets his animal consumption to almost zero. And some day there will be other options.

Enzo sniffing Royal Canan vegetarian dog food

By the way, you can analyze any ingredient list to see if it's vegan, by looking up individual items. Or you can cut and paste into the search field on the website DoubleCheckVegan.com. All of the main ingredients, listed on each company website, come up vegan for both foods, but some of the minerals come up “maybe vegan.” Dicalcium phosphate, for example, is one ingredient, a mineral often used in pet foods, that is sometimes derived from rocks, sometimes from whey in milk.

“I recommend that dogs fed vegetarian diets be monitored by a veterinarian,” said Larsen, “Including not just physical examinations and standard bloodwork but also plasma amino acid concentrations and serum vitamin B12 concentrations at least every six months.”

Not All Vegan Dog Foods are Healthy

Just as it's important for you to eat the right foods to be a healthy vegan, making sure you get vitamin B12 and more, it's also essential that you are thoughtful if you switch your pet. You can't just mix up some kale and tofu and hope for the best—even if you can get your pet to eat it.

In fact, most vets seem to cringe when customers talk about making their own pet food, especially if it lacks nutrients from animals.

“Homemade options may also be OK, but any homemade diet should be formulated by a board-certified veterinary nutritionist and customized to the individual pet to help ensure adequacy,” said Larsen.

You see, not all nutrients in animal-based foods are available in the same portion in plant-based foods, and dogs needs are different from humans.

In fact, dog nutrition is so complex, in a study five years ago Larsen did with colleagues looking at all available vegan dog and cat foods, every one sold over the counter (as opposed to via vet approval) were inadequate. They lacked sufficient amounts of needed amino acids, the building blocks of protein, and they didn't follow package labeling protocol of the World Small Animal Veterinary Association.

“My opinion is that proper labeling is important, and somewhat reflects the expertise and knowledge of the company,” said Larsen. “After all, if they cannot produce a legal label I have little confidence that they are mastering the many, many other details necessary to manufacture a balanced, wholesome diet.”