Father Terry Martin, a Catholic priest in West Sussex, became a vegan almost three years ago. The transition was fairly abrupt: he was alone eating a roast dinner with his dog Pepe on his knees (“I know,” he says. “Terrible.”) when he was struck by the realisation that the animal he was eating had been “just as sentient as the one sitting on my lap”. At the time, Pepe, a cockapoo, was also a strict carnivore. “I actually raw-fed him, so talk about going from the ridiculous to the sublime,” says Martin. Raw-feeding involved buying prepared, frozen raw-meat meals and defrosting them. “He liked it, and for a while I was a bit of an advocate for it, but when my ethics led me to become vegan myself I thought, I can’t actually have meat and dairy products in the house any more. It’s just not something I’m prepared to do. So I looked into vegan food for dogs.” These days, both of Father Terry’s dogs, Pepe and George – a more recent rescue – eat a plant-based diet. “By the time I’d got George I’d gone vegan, so he was vegan from day one with me, but of course he was six months old when he came to me off the streets of Greece, and I don’t know what he’d been eating before.” Projections suggest that the global vegan pet food market, worth $9.6bn (£7.8bn) in 2020, will generate $16.3bn annually by 2030. Until recently, choice was limited, but several new UK based brands – including The Pack, Omni and Noochy Poochy – have started up in the past few years. In 2020, Lily’s Kitchen – a “natural” pet food brand that includes vegan dog food – was acquired by Nestlé Purina PetCare, the second-largest pet food company in the world. But the idea of vegan dog food is still greeted with scepticism and, in the case of the British Veterinary Association (BVA), an abundance of caution. The organisation’s official advice suggests that while dogs can theoretically be fed a vegan diet that meets their nutritional needs, not enough is known about the effects to consider it safe. “We don’t recommend it yet, just because the long-term studies haven’t been done,” says Justine Shotton, the president of the BVA. “While the short-term studies that we’ve seen suggest it could be just as good as other types of food, there hasn’t been the evidence base of lifelong studies of feeding these pets these foods.” Advice from the Pet Food Manufacturers Association (PFMA) is just as circumspect. Although it says that “dogs are omnivores and can adapt to a well-balanced vegetarian diet”, its fact sheet on the subject maintains that “vegan foods (no animal products) should be carefully checked by a vet or animal nutritionist as they may be deficient in arginine, lysine, methionine, tryptophan, taurine, iron, calcium, zinc, vitamin A and some B vitamins. Meticulous attention to detail would be needed to assure nutritional adequacy and palatability.” It also cites studies showing that dogs fed a vegetarian diet were often deficient in protein, essential amino acids and other nutrients, but the studies are old, predating the much wider availability of commercially prepared “complete” plant-based foods. Michelle Thomas has been a vegan for six years. Her two-year-old Hungarian vizsla, Loki, went vegan at 10 months, after a recommended two-month transition period. “Being vegan myself, what I was feeding my dogs was becoming increasingly troubling to me, as it went against the way I was living,” Thomas says. “So I started looking into whether I could safely feed my dog a plant-based diet.” Was it primarily an ethical decision? “Absolutely, it’s ethical,” she says. “And it’s also hugely environmental. We’re in a true planetary emergency, and we can no longer ignore the part that animal agriculture is playing in destroying the planet.” Plant-based pet feeding is often presented as a time-consuming challenge, but Thomas insists it’s no more trouble than what she was doing before. She feeds Loki a commercial vegan kibble called Solo Vegetal, made from rice, potato, spinach, apple, carrot and different vegetable proteins. It’s expensive – roughly the same cost as any special diet pet food from a veterinary practice – but no supplements are required. “I have absolute confidence in it,” Thomas says. “And if I didn’t, you know, I would be struggling with my principles and my ethics and probably feeding him something I didn’t want to feed him.” Rachael was also a committed vegan, but didn’t initially feel the need to force her two dogs – a border terrier and a labrador – to adhere to her regime. “I’d always been very much of the opinion: of course dogs need meat – they’re carnivores,” she said. “They’re descended from wolves – they have to have it.” Like Thomas and Father Terry, Rachael’s search for more information on plant-based pet feeding led her to Dr Arielle Griffiths MRCVS, a veterinarian and the director of Just Be Kind Dog Food, who offers nutritional advice and vegan dog food recommendations on her Just Be Kind website. Griffiths, it transpires, was also a relatively recent convert to veganism, both for herself and her dog Ruff. “Four years ago, I would have never dreamed that I would be going down this path,” she says. “Because we were buying normal dog food. I mean my husband would go on to Amazon and say: ‘OK, let’s see what the cheapest food is at the moment.’” Griffiths’ mission began while she was working as a vet for the animal charity the People’s Dispensary for Sick Animals (PDSA). “I had one particularly gruelling day where I had to put four animals to sleep for obesity-related illness – cats and dogs,” she says. “It was horrible. I got home and I just said: ‘No, this is crazy. I’m going to do something about this obesity epidemic.’” Griffiths threw herself into the study of pet nutrition, and was surprised by what she found. “The more I looked at it, the more I realised that, just like humans, the more plants you add into the diet, the healthier the pet will be.” People cite different reasons for moving their dogs to a plant-based diet. Some of the concerns are ethical – the owners are usually vegan themselves. There is also the issue of sustainability: pets consume a fifth of the world’s meat and fish, although much of that is a byproduct of meat production for human consumption. Increasingly, however, people are putting their pets on vegan diets for their health. This flies in the face of conventional thinking, which is that a vegan diet is only potentially feasible for dogs, and wholly unsuitable for cats. “I think it’s important to recognise that while dogs theoretically can eat a vegetarian or vegan diet, cats are obligate carnivores, and we really do not recommend feeding them this because of the very serious health concerns that can result,” says Shotton. Griffiths disagrees, even when it comes to cats. “Cats are so unhealthy in this country, terribly unhealthy – obesity problems and allergy problems, and arthritis problems,” she says. “If cats were to go plant-based, we’d see a huge change in health in cats.” Both cats and dogs have very specific nutritional requirements, including vitamins, amino acids and essential fatty acids that are normally found in meat. But supplemental nutrients are often added into ordinary dog food anyway, because processing eliminates them, and supplements including vitamin D3, omega fatty acids, L-carnitine and tryptophan can be derived from non-meat sources. “As long as you’ve got those, the protein levels you can get with plants is equivalent to the protein levels that you can get with meat and fish,” says Griffiths. Most plant-based complete pet foods meet the nutritional guidelines set out by the PFMA and the European Pet Food Industry Federation (FEDIAF). But not all do. “There are some plant-based companies, sadly, in the UK that don’t follow the proper FEDIAF guidelines,” says Griffiths. “They’ve been around for a long time, they’re not balanced and they haven’t got these valuable additions. They haven’t followed the times.” Because of the nutritional complexities surrounding plant-based feeding, it has been suggested that people who feed their pets an insufficiently nutritional vegan diet could face fines or even imprisonment for animal cruelty, but this ignores one important fact: pet owners are already presiding over a growing, and largely unpunished, obesity epidemic. A recent survey-based study published in the journal Plos One showed that dogs on vegan diets actually had on average fewer veterinary visits than those on meat diets, and fewer health disorders. The reasons for this are not known, but the author of the study, Prof Andrew Knight, said: “One of the most common health problems for dogs is being overweight or obese and it is unfortunately common that when we do tests on the commercial meat-based diets, there are more calories.” Another study conducted by the Ontario Veterinary College last year found that cats that were fed a plant-based diet – about 20% of the survey sample – also suffered fewer adverse health effects than meat-eating cats, as well as a similar lifespan. Although vegan herself, Rachael had been feeding her border terrier a raw meat diet, hoping it might alleviate his lifelong stomach troubles. “I’d heard so many things about how miraculous it was when it came to curing dogs of absolutely everything under the sun,” she says. “No matter what condition it is, stick ’em on a raw diet and they’ll get better.” So what happened? “Number one, he hated it,” says Rachael. “You could immediately tell he was not keen, but they say persevere with it. Don’t feed them anything else, and eventually they’ll get so hungry they start eating. Well, yeah, that happened.” The raw food was one stop in a long search to find a diet that would ease the dog’s gastric issues, beginning with a variety of different meats. “We tried every animal under the sun,” Rachael says. “I think we were down to: ‘Let’s try crocodile next.’ It was that bad, trying to find a food that would not make him horrifically ill four or five days a week.” She tried an insect-protein diet “based largely on the black soldier fly larvae”, but that didn’t help. Then came the barf diet, short for biologically appropriate raw food. The raw feeding movement gained a lot of interest after a 2007 recall of more than 5,000 pet food products worldwide, due to contamination with melamine and cyanuric acid. The resulting suspicion of processed pet food led to people seeking out more natural alternatives. The barf diet is supposed to replicate how animals might feed in the wild. Unfortunately for Rachael’s terrier, barf was more than just an acronym. “He ended up in the vets twice with two really quite nasty campylobacter infections, which manifested as really extreme vomiting, and just blood pouring out of his back end,” she says. “We always bought the raw food from really reputable suppliers, but at the end of the day, you’ve been defrosting a load of meat and offal and putting it in a bowl and feeding it to your dog.” She had wanted to switch him to a vegan diet, largely for environmental reasons, but was wary, given his health issues. So she started vegan-feeding her other dog, a labrador, first. “Almost like a guinea pig – that sounds terrible,” she says. “But he’s got an iron constitution, that dog. He once ate an entire bag of chocolate coins at Christmas, with the foil.” When the lab took to the vegan food immediately, she tried it out on the terrier. “What I wasn’t expecting was that it would almost – and I say almost because I’d be lying if I said they were completely gone – but it almost cured him of stomach issues that had plagued him for 10 years of his life,” she says. “A very happy side-effect.” In the long history of her dog’s problems, the possibility that a plant-based diet might help had never been put to her. “No vet had ever said to me, try taking the animal products out of the diet and see if that helps,” she says. “It was always: ‘Remove the grain, try this meat, try that meat, have you tried goat, have you tried kangaroo?’” All of the owners I spoke to said their dogs were healthy and happy on a plant-based diet. “He’s perfect, spot-on weight,” says Thomas of Loki. “Super-happy, fit, massively high energy. And yeah, just he’s just loving life.” None of them said the switch was difficult – Father Terry didn’t bother with the recommended transition period, because his dog loved the food straight away. But they all stressed the importance of educating yourself thoroughly before transitioning a dog to a plant-based diet. “You have to do your research and know what you’re feeding,” says Rachael. “I have come across the occasional person who has tried feeding their dog plant-based, and I’ve looked at what they’ve been feeding them and thought, that’s not quite right.” “I think the question is not really whether the food we feed our dogs is vegan or not,” says Thomas. “The question is more: if I can feed my dog a delicious, nutritious, balanced food that’s healthier for them, kinder to other beings and kinder to the environment, then why on earth wouldn’t I?” Rachael remains wary about the idea of feeding pets a plant-based diet solely for ideological reasons, because all dogs have individual needs. “My dogs are my absolute world, and I would never do anything that I felt could jeopardise their health or happiness just because it would make me feel better,” she says. “I don’t say that my dogs are vegan. I can’t make my dogs vegan any more than I can make them support Labour.” She is also wary of the backlash that the owners who feed their dogs a plant-based diet can face on social media. “On Facebook, I’ve tried entering into conversations with people a couple of times,” she says. “It goes horribly, horribly, horribly. I’ve had people say they want me arrested and imprisoned.” For this reason, she asked that her surname – and her dogs’ names – not be used. Given the controversy surrounding vegan pet foods, what did everybody’s regular vets think of the switch to a plant-based diet? None of the owners interviewed, it turns out, has quite broken the news. “I’ve told the vet nurse, but I haven’t actually told the vet yet,” says Thomas. “Just purely because it hasn’t come up in conversation.” “To be quite honest, even though I’ve seen the difference in my dog’s health for myself, I wouldn’t expect a good reaction,” says Rachael. “If I have to have the conversation with him at any point I will, but we’ve not had to go back there for any of the stomach issues.” Even Father Terry hasn’t told his vet about what he’s feeding Pepe and George. “Of course, if they did ask I would be honest about it,” he says. Griffiths, a vet herself, is not despairing about what she sees as closed-mindedness in some of her colleagues. “I feel massively positive,” she says, “even though l do feel very alone. And I feel like a small voice. But the changes are so great on the human side – to be vegan now is the easiest thing in the world.”