Toru Hanai / Reuters

When my boyfriend and I got our first cat, Pete, a long-legged tuxedo, we fed him Friskies.

Depending on the type of person you are, you either breezed through that sentence finding nothing remarkable, or you immediately judged me for buying pet food—ahem, pet “food”— made of ground-up chicken bones, beef tallow, soybean hulls, and other delightful byproducts.

I know because we were, at the time, living in Berkeley, California. Pete came to us from a relative in Kentucky, and to ease the cross-country move we fed him the same Friskies he had been happily devouring. But we’re not monsters. And we had disposable income to lavish on our cat. So in California, we went shopping for new food at our local pet store, where the sales guy asked me about Pete’s previous diet and, after I answered, shot me the most withering look I received in my entire time in Berkeley.

If you can’t tell, pet food is a touchy subject for me. Pet food has become fraught. What was once a simple choice between wet and dry food now entails selecting from a dizzying array: corn-free, potato-free, rice-free, oat-free; organic, grass-fed, cage-free; frozen raw meat; alternative proteins like kangaroo and alligator; specific diets for purebreds from Maine coons to miniature schnauzers; and, of course, vegetarian and vegan formulations. If how we humans eat has taken on a moral dimension, so has how our pets eat.

So when I heard that a Berkeley-based start-up called Wild Earth was experimenting with sustainable “clean protein” for pets—made from a fungus called koji for dogs and lab-grown mouse meat for cats—I was intrigued. I mean, it seemed almost too on the nose.


“I always thought vegans were extremist weirdos,” says Ryan Bethencourt, who is now actually a vegan. Bethencourt is the co-founder and CEO of Wild Earth. In June, I met him at a vegan, dog-friendly cafe in the Bay Area, where he ordered rolls with cheese made of tapioca and coconut. A miniature husky with fur dyed bright pink lounged nearby.

Bethencourt’s conversion happened eight years ago in Los Angeles, when a group of vegans introduced him to the documentary Earthlings. The film was “super intense,” he said, and it drew for him a through line between civil rights and animal rights. He had been a pescatarian, and he went vegan overnight. As an animal lover who also fosters dogs for a local shelter, he put two and two together. “Why am I feeding animals to animals?” he asked. “That just wasn’t consistent for me in terms of my personal ethics.”

In his professional life, Bethencourt works with biotech start-ups, and biotech, he realized, held a solution. As an investor himself and a co-founder of the start-up accelerator IndieBio, he has advised meat- and animal-product-alternative companies like Memphis Meats (chicken, beef), Finless Foods (fish), and Vitro Labs (leather). Elsewhere in the Bay Area, biotech companies like Bolt Threads (spider silk), Impossible Foods (a bleeding, meatless burger), and Zymergen (microbes) have attracted lots of buzz. Fundamentally, all of these companies rely on cells grown in bioreactors to help manufacture their products. So why not use the technology to manufacture pet food—especially cruelty-free, sustainable pet food?

Bethencourt and his co-founder, Ron Shigeta, launched Wild Earth in March with a teaser for its first product: dog treats made from koji. Koji is a fungus traditionally grown on grains to make soy sauce, miso, sake, vinegar, and other fermented foods in Asia. Lately, it’s become popular among foodies. Wild Earth cultures koji in bioreactors, feeding it beet sugar that the fungus converts into protein.

“It tasted like a Cheez-It,” Bethencourt said—he knows because he’s eaten it. “The CEO should always eat their own dog food,” he added. “I wonder how many other dog-food CEOs would say that.” The treats are supposed to be commercially available in October. “We really want to get pet parents”—that’s the preferred term over pet owners—“comfortable with koji as a new protein source,” Bethencourt said, and the next step is a koji-based dog kibble.


Lest we forget the cats, Wild Earth is also in the early stages of an even more ambitious project: growing mouse meat in a bioreactor.

It makes a kind of logical sense. Cats eat mice. They are obligate carnivores, so Wild Earth didn’t want to make koji cat food. (In particular, cats need an amino acid called taurine. It comes from meat, but can also be synthesized and added to plant-based kibble.) And mouse cells happen to be some of the best studied thanks to the use of lab mice in science. But lab-grown mouse meat is not a particularly appetizing idea. Pet-food companies advertise their wares as simulacra of human food: chicken and rice medley, purrrfect paella, o’fishally scampi. It’s about appealing to the human as much as the pet.

After Bethencourt boasted of eating his own dog food, I asked if he would eat the mouse meat, and his enthusiasm noticeably cooled. “You know what? Yes,” he said after hesitating. “Once it’s serum-free, I’ll taste it.” (Mammalian cells often require serum derived from fetuses inside slaughtered cows to grow in a lab. Growing cells without it has been a big hurdle for lab-grown meat.) “It doesn’t look particularly appetizing,” he admitted. “It has a kind of runny texture.”

The mouse-meat project has sparked a backlash from vegans, who left a rash of one-star reviews on Wild Earth’s Facebook page.

Lab-grown meat—for humans or pets—remains controversial among vegans. Bethencourt has staked out what he says is a pragmatic stance: It’ll reduce the number of animals who have to die for food. For other vegans though, it comes with a more fundamental problem. Matt Johnson, an organizer for the animal-rights group Direct Action Everywhere (whose members made headlines last year by wrapping themselves in fake blood and plastic to protest a Berkeley butcher shop), put it this way: “It still reinforces this notion that animals exist as commodities, that they exist as an object for us to consume.” He feeds his cat vegan food from Ami.

Tony Buffington, a vet at the UC Davis School of Veterinary Medicine, told me cats and dogs can certainly stay healthy on a vegan diet that contains proper nutrition. (The Association of American Feed Control sets nutrient profiles for cat and dog food.) The nutritional needs of “neutered adult sedentary animals”—to use his words—are not super complicated. But I could tell he still found the idea a bit ridiculous. “There’s an ethical challenge to making others the means to one’s end. To me that’s what people are doing,” he said. “When they’re feeding dogs and cats vegan foods, they’re making dogs and cats abide by their own personal philosophical beliefs.” He also took issue with the term pet parent. “Maybe it’s because I’m a human parent and an animal owner,” he said, “and I’m old.”

He has a point about simply being old. In the past few decades, pets have become ever more cherished and expensive members of the family. Americans collectively spent nearly $70 billion on their pets in 2017, compared to $17 billion in 1994, according to the American Pet Products Association. Pet-food sales have also doubled since 2000, much of that growth in expensive premium brands. Our pets are eating more expensively than ever, and they’re taking up our organic, raw, vegan, and grain-free diets.


Last Thursday, Wild Earth was chosen as one of the first companies for a pet-focused start-up accelerator co-funded by Mars Petcare, the company behind brands like Pedigree, Whiskas, and Royal Canin. (It was a busy week: That Monday, the company also announced that Peter Thiel and Founders Fund had invested $500,000.) Big pet food is getting into lab-grown food.

Back in June, Bethencourt dropped hints about a meeting with Mars. The pet-food industry, he said, was now especially interested in alternative proteins. Just as allergies have been on the rise in humans, cats and dogs have started to develop reactions to common meats like chicken or beef. In response, pet-food companies now offer exotic proteins like kangaroo, mussel, mackerel, ostrich, and wild boar.

I happen to be very familiar with Mars’s alternative proteins because a 50-pound bag of Royal Canin hydrolyzed soy protein arrives at my door every few months. When we got a second cat, Wiley, he came with a litany of digestive problems that turned his poops into room-clearing stink bombs. We cycled him through different kinds of food to no avail. Finally, our vet suggested he had irritable bowel syndrome (or food allergies; it was unclear) and prescribed a hydrolyzed-soy-protein diet. Whatever the problem, his poops got better. My parents, who fed their childhood cats table scraps, found our purchase of prescription cat food hilarious and decadent. But here we are.

After starting with the extremely niche idea of selling vegan kibble to vegan pet owners, Wild Earth is expanding to a wider circle: non-vegan pet owners who are nevertheless willing to pay for specialized diets.

And actually, Bethencourt’s ambitions are even bigger than that. At scale, he thinks, koji can be cheaper than conventional pet foods. He knows he can’t sell to everyone by touting vegan and alternative proteins, but money talks. And that, he says, is how you get meat consumption to truly go down: “I should be able to compete with even the lowest-price dog food and at that point we win.” No additional moralizing necessary.

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