A vegan vet on plant-based diets for dogs and cats.

First, I graduated in Veterinary Medicine. I was already a vegetarian. Then, many years later, unemployed and quite disappointed with my profession, I went vegan. There was a time I thought being vegan and a veterinarian was not compatible. But then I decided to be brave and tell the world I was going to change things, and magic happened. I met another vegan vet, and we launched our vegan business: a veterinary clinic.

Here in Spain, we are pioneers. As far as I know, we are the only ones that don’t sell any nonvegan commercial food for our animal companions. Feeding your cat or dog vegan food is still a very controversial topic, even among vegans. It is quite disheartening to hear vegan people reciting the same old excuses one would hear from a nonvegan person. Even veterinarians, most of them quite ignorant about the basics of nutrition, will say cats are strict carnivores and so they need meat to survive, or will tell you that if you feed your cat only vegetables, he will die of taurine deficiency. The same myths are repeated again and again, no matter how many decades vegan pet food brands have been selling their products or how much research you present to back up your knowledge. You might even be accused of animal abuse, while every day at the veterinary office, you are tired of seeing animals suffering of obesity, diabetes, cancer, or liver and kidney diseases, probably caused by bad quality, meat-based, pet food, but no one cares about that. They are more worried about taurine. The situation resembles the global situation in human health, where everybody is worried about vitamin B12, but the solution is simple: you use supplements.

Well, what’s reality then? Luckily there are vegan veterinarians in other countries and I learned a lot from them. Dr. Andrew Knight, author of this article about the facts and myths on vegan animal diets, has published a few scientific articles describing the process of manufacturing meat-based pet food and how switching to a plant-based diet can even bring beneficial effects to our animals. Owners report decreased ectoparasites (fleas, ticks, lice and mites), arthritis, diabetes, cataracts, urogenital disease and improved vitality (1).

Dr. Armaiti May, an integrative and vegan veterinarian, gives conferences about vegan food for animals. She explains that most allergies in dogs and cats are caused by animal proteins, so undoubtedly a vegan food will improve this condition. Her advice, the same I give my clients, is to make a slow transition to the new kibble and control urine pH, especially in cats, as some individuals are prone to form urine crystals. But this problem is not exclusive of vegan diets. FLUTD (feline low tract urine disease) has always been a well-known ailment for veterinarians, long before vegan food came to existence. She claims only around 10-15% of cats can’t fully make the transition due to this ailment, and in this case we can always combine a 50% of meat-based food with a 50% of vegan food. For the rest of cats, there is no problem, and in my practice, though precautions are never too many, I don’t see more incidence of FLUTD in cats that are fed vegan food. Also, we are recently starting to see that stress plays an important role in its development.

It is true that long-term studies are still needed to assess the complete safety of vegan food for cats. So far, there is only a report, written by Lorelei Wakefield and published in 2006 (2), where 34 cats that had been fed a commercial or homemade vegetarian diet for over a year were evaluated. It is a small sample and further investigation is needed, but the results were positive, incredibly no feline died after such mistreatment! Serum cobalamine concentrations and blood taurine concentrations were determined, and all were within the reference range, with the exception of taurine concentrations in three cats that didn’t receive any vitamin supplement, though they were described as healthy by their caregivers.

“Here in Spain, we are pioneers. As far as I know, we are the only ones that don’t sell any nonvegan commercial food for our animal companions.”

So, it is obvious we must be cautious and always recommend periodical blood tests, as we would do in animals with conventional diets, but I think veterinarians as a whole must keep an open mind to vegan diets and always seek objective, quality information, so that we can give proper advice to our vegan clients. Regardless we are vegan or not, it is our responsibility to give that choice to people that are truly concerned about ethical decisions. And of course, if we, as veterinarians, don’t care about the lives of those millions of animals that are exploited and killed unnecessarily every year, how can we claim we are here to protect them? How coherent is that with a profession that in theory looks after the welfare of all animals?

I really wish all veterinarians were vegan, but I guess this is still too far on the horizon. However, we can and must work for a vegan future. Peace begins on your plate and that also includes the food choices we make for our animal companions.

In the picture, you can see my partner’s cat Osiris, enjoying his homemade vegan ration. He came suffering of severe respiratory disease, he was raised on a whole plant-based diet and he has grown to be a healthy (and a bit chubby) mischievous cat.

Dr. Mónica Manzanares is veterinary manager in Veterinaria Natural Alma Vegana, one of the first vegan veterinary offices in Spain.


(1) Knight, A. & Leitsberger, M. (2016). Vegetarian versus meat-based diets for companion animals. Animals 6, 57. 20 pp.

(2) Wakefield, L.A. Shofer, F.S. Michel, K.E. (2006). Evaluation of cats fed vegetarian diets and attitudes of their caregivers [2006]. Journal of the American Veterinary Medical Association 229(1):70-3.

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Note from the editor: Plant-Based Nation explores many plant-based lifestyles in an effort to promote education and outreach about plant-based living. We want to thank Dr. Mónica Manzanares for sharing her expertise as a Veterinarian who offers support to those interested in feeding their companion animals a nutritionally balanced, plant-based diet.
– Tabby

Suggested Reading:

Obligate Carnivore: Cats, Dogs & What it Really Means to be Vegan written by Jed Gillen, available on Amazon Kindle

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