[bright music playing]

[Professor Tonatiuh Melgarejo] Dogs have been living alongside humans for more than 20,000 years. They are very loyal. They don't act with a hidden agenda. And I just enjoy my time a lot with animals and, uh, less with humans. We have about 91 million dogs living in the United States. Most of these dogs are eating a meat-based diet. The amount of meat that we use for dogs and cats, it's equivalent to the meat consumption in the country of Italy. And if all dogs and cats in the US had their own country, they would be the fifth-largest meat-eating country in the world. And because we are feeding these dogs a meat-based diet. It is estimated that up to 30 % of the total carbon footprint for food production in the US comes from dog and cat food. To make matters worse, we are seeing dogs with similar health problems as people have on a diet that is heavy on animal products, like obesity and certain cancers. 

[Dr. John Tegzes] There are many toxins that can affect the meat that's used to make dog food. So if we were to look at substances like lead, from decades of automotive exhaust that have polluted the ground near highways and roads, most of that partitions into organs like the liver. And for pet food in particular, we often use those organ meats as part of the food that we're putting together for them. 

[Professor Tonatiuh Melgarejo] So I was taught dogs are carnivores. Period. But I have travelled to some developing countries in Africa, Asia, and Latin America, and I was surprised that in some of these countries, dogs don't even eat meat or dairy because they don't have the money. And the dogs are perfectly fine. They're healthy. So we wanted to answer the very basic question, what happens when you take a clinically-healthy dog and you feed that dog a vegan diet?

[dog grunts] 

For the study, we selected 15 dogs, and we fed them for a year this plant-based diet. 

[man] Hi, Smash. Hey, Smash. 

In dog years, a year, it's equivalent to six to eight years in humans. We are doing a complete physical examination. Extensive blood and urine analysis, as well as cardiac ultrasound exams.

[woman] We have a long axis view. We see the left heart here.

[Professor Tonatiuh Melgarejo] And we are going to follow these dogs for 12 months. We need to get blood from you, Smash, so …

[Mark Steidler] Smash has had quite a few health problems. He has a lot of allergies. He also has had a ton of skin issues his entire life. So scratching himself constantly. Come here. So there are only a few recipes that I can feed him. Knowing that he's allergic to a lot of animal-based diets, I did find out that there was this plant-based study going on and wanted to enroll him and give him another option out there. Something that I'm real interested to see is how my dogs do on it, to see if their, uh, health improves.

[Professor Tonatiuh Melgarejo] The main source of protein in the vegan dog food used in this study is pea protein. There's a variety of other plant-based ingredients that provide all the nutrient requirements of a healthy diet for dogs. 

[Gloria Corral] You know, a lot of people think that because we don't give them meat, they don't enjoy the food. But our dogs, they enjoy the food. They really, really do.

[Professor Tonatiuh Melgarejo] When I was doing this study, one of my students came and said, "Dr. Melgarejo, I'm sorry, I really respect you, but my classmates think the Mexican doctor is crazy."

[laughter] 

Some of my colleagues told me, "Oh, that's cute."

[laughter] 

"You're looking at, uh, vegan, uh, diets for dogs." "That's not really good." And I said, "Yes, the best thing to do: present solid data." So the question is, can we give these clinically-healthy dogs a plant-based diet for a year?

[dog barks]

[laughter] 

[Dr. John Tegzes] The results from the researchers here have been quite surprising. I'm not gonna lie. There are certain things that I expected and certain things that surprised I think even the researchers themselves. Good boy.

[Professor Tonatiuh Melgarejo] At baseline, all dogs were clinically healthy. We collected more than 3,000 parameters in one year from these dogs. For example, vitamin D, it's very important for bone metabolism and also for immunity. The vitamin D in seven out of these fifteen dogs was insufficient. At the end of the year, all of them, they were within normal limits. 

[Dr. John Tegzes] The vitamin D concentration that they were able to measure in dogs normalized after more time on a plant-based diet. That really is contradictory to common thought.

[Professor Tonatiuh Melgarejo] Because the general consensus is that we get vitamin D almost exclusively from animal products. So, we saw that dogs that were clinically healthy maintained health, but looking deeper into these biomarkers, they were healthier. And that was nothing that we were expecting.

[Suzanna Corral] She has more energy. She seems to be very healthy and active, and she wants to run and play every day.

[Dr. Nathan Sharp] The athletic performance that a lot of these animals can end up with is super high, and you would not expect that out of a vegan diet. We often think of vegan diets as, like, these kind of lean, not muscle-building kind of diets, and these dogs get beefy. They're strong, they're healthy, but they're not overweight.

[Professor Tonatiuh Melgarejo]The data is so clear. When it comes to diet and dogs and cats, you need to present solid, cold data. That's the only way to move this forward. We are happy to say that the results of our one-year clinical study on plant-based nutrition in dogs have been published with open access for everyone. Dogs and cats are not going to go away, and we need to provide a sustainable, healthier food, not only for the dogs, but for our planet.