People make decisions about what to eat based on their beliefs and backgrounds, including health, political, environmental, cultural, or religious ideals. For some people, that carries over into what they choose to feed their dogs and cats. In one study, 100% of people who fed cats a vegetarian diet reported eating vegetarian diets themselves.
Amy Short from Brooklyn, N.Y., tells WebMD that she began feeding her domestic shorthaired cats, Olive and Georgia, a commercial vegan diet as 3-month-old kittens. “Because I am a vegan, I strive to live my life as compassionately as possible,” she says. “I had real dissonance with the idea (and brief practice) of buying animal-based food for my pet animals.”
Besides a little dental trouble for Georgia and springtime allergies for Olive, Short says the cats, which are now 8 years old, are “healthy, happy.”
Short says she hasn't gotten much pushback from veterinarians, in part because she hasn’t told some of them about the cats' vegan diet.
But feeding dogs and cats a no-meat diet is controversial and can be risky. Here's what you need to know if you're considering it.
Vegetarian Dog and Cat Food Warnings
Lew Olson, PhD, author of Raw and Natural Nutrition for Dogs, makes this analogy: “Trying to feed a cat a vegan diet would be like me feeding my horses meat. You’re taking a whole species of animal and trying to force it to eat something that it isn’t designed to handle.”
“For cats, it’s really inappropriate. It goes against their physiology and isn’t something I would recommend at all," says Cailin Heinze, VMD, a board-certified veterinary nutritionist and assistant professor of nutrition at Tufts Cummings School of Veterinary Medicine.
"For dogs, certainly vegetarian and vegan diets can be done, but they need to be done very, very carefully. There is a lot of room for error, and these diets probably are not as appropriate as diets that contain at least some animal protein," Heinze says.
Vegetarian Dog and Cat Food Risks
Dogs and cats process certain nutrients differently than people do. Here are two examples:
Vitamins A and D: Dogs and cats cannot make vitamin D in their skin, so it needs to be in their diet. And the vitamin D needs to be D3, which comes from animal sources, not D2, which comes from plant-based sources. “People and dogs can use D2 to some extent, but cats really need D3,” Heinze says.
Taurine. Dogs can make taurine if provided the right building blocks through dietary protein. Cats cannot make their own taurine at all, so it is regarded as an essential amino acid in this species and must be present in adequate amounts in the diet. Both species can suffer taurine deficiencies.
The risks of feeding dogs or cats vegetarian or vegan diet include:
- Inadequate total protein intake (less than the 25 grams per 1,000 calories recommended)
- Imbalance of the certain amino acids, such as taurine and L-carnitine (dogs and cats) or essential fatty acids arachidonic acid (cats only), in particular
- Deficiency in vitamins and minerals (such as B vitamins, calcium, phosphorus, and iron) that are obtained ideally, or only, through meat or other animal products
If allowed to continue long enough, these dietary problems can lead to serious and sometimes irreversible medical conditions. The one veterinarians mention most often is taurine-related dilated cardiomyopathy (enlarged heart with weak contractions and poor pumping ability). Low taurine can also lead to reproductive failures, growth failures, and eye problems.
“We did see a case of a cat that almost died as a result of taurine deficiency,” says Jennifer Larsen, DVM, PhD, board-certified veterinary nutritionist and assistant professor of clinical nutrition at the University of California, Davis veterinary school. “The owners were feeding a vegan cat kibble, so a commercially available vegan diet, and they were mixing that diet with cooked chicken breast, for some reason, but it was not enough taurine for the cat, obviously, and it resulted in a near-death experience for this animal.”
“I can tell you the people who almost killed their cat felt incredibly guilty and incredibly angry, as you can imagine,” Larsen tells WebMD. “They were not feeding that diet to be malicious or to harm their cat, but that’s what happened.”
Dos and Don’ts
If you are considering a vegan or vegetarian diet for your dog or cat, "there is a lot to think about,” Larsen says. “It isn’t something to be taken lightly.”
Here are four guidelines to follow:
- Never feed vegetarian or vegan diets to puppies and kittens or to dogs and cats you plan to breed.
- Only consider or feed commercial diets that have gone through feeding trials and meets the requirements for AAFCO (Association of American Feed Control Officials) compliance.
- Consult with a veterinary nutritionist who can analyze your commercial or homemade vegetarian pet diet and make recommendations for additional health safeguards.
- Schedule more frequent wellness exams, including blood work, with your family veterinarian -- at least twice a year, even for young pets eating vegetarian diets.
Specialty Veterinary Diets
In some medical cases, veterinarians use specially formulated pet foods only available by prescription that are made from nonmeat protein sources (egg or soy, for example) either to diagnose or treat these conditions:
- Food allergies
- Liver disease
- Bladder stones
Veterinarians typically use these foods -- which have been developed, tested, and made by large pet food companies -- while they closely supervise the pet’s overall health and specific conditions.
Vegetarian Pet Diets and Supplements
To make up for imbalances or deficiency in a pet’s diet, people who choose to feed dogs and cats vegetarian or vegan diets often turn to nutritional supplements.
“Experimentally, there are ways to get around it,” Heinze says, “but you’re adding a lot of chemically synthesized nutrients to replace what would normally be in an appropriate diet.”
Pet Food Ethics and Pet Selection
Pet care professionals who warn against vegetarian diets for dogs and cats empathize with pet owners’ concerns that lead to these decisions. But there are options other than species-inappropriate diets for dogs or cats.
“People do this to make themselves happy,” says Olson, who worked in psychotherapy before changing careers in the early 1990s. “It’s not about the animal. When people tell me they want to feed a vegan diet, I say, ‘Get a goat, get a rabbit.’”