Vegan Cats

Some cats can thrive on a vegan diet—but it takes lots of extra effort, care, and money to avoid dangerous problems.
Last Updated: March 18, 2018

While it’s surprisingly easy for most people to become vegan, getting your cat onto a vegan diet is roughly a million times harder. Cats are natural carnivores and their digestive system is nothing like our own. They’ve got pointier teeth, much stronger stomach acid, and shorter intestines—all hallmarks of true carnivores.

The first problem associated with putting a cat on a vegan diet involves finding food they’re willing to eat. Cats are notoriously inflexible when it comes to trying new foods. They have no interest with in working with you, and will make no effort whatsoever to meet you halfway. These are, after all, creatures who can dismiss a given food forever, based on a single sniff. That hardly seems fair, but that’s how cats are.

There is consequently no one-size-fits-all approach to feeding cats. I’ve met cats who delight in eating pureed vegetables. Unfortunately, my cat, Conrad, is not one of these obliging sorts. He wouldn’t eat a spoonful of veggies if you offered him a lifetime supply of catnip. Yet, oddly, Conrad will happily devour something few cats will touch—he adores fruit. He’ll scarf down any fruit at all. I’ve fed Conrad apples, bananas, cherries, and even blueberries. As long as I break up the fruit and hand-feed it, so his tongue can tear into it, Conrad’s the happiest fellow on earth.

Of course, fruit doesn’t begin to provide all the nutrients a cat needs. So it’s not enough merely to find vegan foods your cat will eat; you need to construct a diet that offers adequate nutrition. And providing adequate vegan nutrition for cats is a daunting task. That’s partly because humans require just nine types of amino acids, all of which are found in abundance in many vegan foods. Cats, by contrast, require eleven different amino acids. And these extra two amino acids, taurine and arginine, aren’t normally found in plant-based foods. Taurine and arginine aren’t just desirable for cats, they are essential—without sufficient taurine, your cat will go blind.

Fortunately, both taurine and arginine are easily synthesized from vegan sources. Any reputable brand of vegan cat food will therefore feature taurine and arginine in their ingredients. But taurine and arginine alone won’t cover a vegan cat’s nutritional needs. Cats typically obtain most of their vitamin A and D from animal sources. And then there’s the matter of arachidonic acid, an animal-based ingredient that nobody outside the cat food industry has ever heard of. Once again, however, all of these nutrients can be derived from plant-based sources. Every vegan cat food on the market should contain all these vital nutrients; just check the ingredients list of the product’s label to verify their presence.

So why did I make such a big deal about the difficulty of feeding cats a vegan diet? You just need to find a good brand of vegan cat food, and make sure it contains all the nutrients I covered above, right?

Unfortunately, it’s not that simple. As we’ve already seen, the switch to vegan food can be a tough sell, no matter how expertly formulated and nutritionally balanced the brand you’ve purchased. Worst of all, since there are only a few vegan cat foods on the market, your cat might hate all of them. What to do then?

All is not lost. Your next step is to get Jed Gillen’s book Obligate Carnivore. Gillen explores the nutrition issues of vegan cats in great detail, while including recipes for vegan cat food that you can make right in your kitchen. Since individual tastes vary between cats, you may need to try a number of recipes before you find one that your cat deems satisfactory. There is nothing more humiliating than spending thirty minutes lovingly preparing a batch of cat food, only to watch your cat give it a perfunctory sniff and then walk away in disgust, without deigning to taste even a morsel. When this happens, you can usually count on your cat shooting you a scornful look over his shoulder as he walks behind the sofa.

But with persistence, you may achieve success. Once you discover a recipe your cat will eat, you must spike all future batches with a specially formulated amino acid and vitamin supplement that is intended to be mixed into homemade cat food. The most popular brand is called VegeCat, which can be purchased online. Don’t spike your test batch of homemade cat food with these supplements until after your cat approves of the recipe. These supplements are expensive and it’s silly to waste them on a test-recipe batch that won’t be eaten.

Some people will decide they want to cook for their cats, even if their animals are willing to eat commercially prepared vegan cat food. That’s because you’ll save a lot of money by preparing the food yourself instead of buying prepackaged vegan cat food. Vegan cat food is up to ten times more expensive than some conventional brands, so the amount of money you’ll save by preparing your own cat food is substantial, especially if you have more than one cat. If you go the homemade route, be sure to add in the supplement mixture to each batch of food you make, otherwise your cat is guaranteed to develop serious, life-threatening deficiencies. It takes under a half-hour of preparation to create a batch of food that will keep in the refrigerator for two weeks.

Whether you’re trying commercial vegan cat food or going the homemade route, there’s a final strategy you can use if your cat rejects every food you offer. That is: start out by mixing only about 20 percent of the vegan stuff into your cat’s regular cat food. Over a few weeks, you can ratchet up the vegan portion until you reach 100 percent. Note that this strategy only works if your cat isn’t totally repulsed by the food in question—you might see waning enthusiasm for eating as you try to increase the proportion of vegan food. And if you’re feeding them dry kibble, many cats will actually dig through the bowl and eat only the meat-containing kibbles. This is a clear indication that your cat is plotting to kill you in your sleep and that you ought to abandon your attempt to feed him that particular type of vegan food.

Finally, keep in mind that some cats every bit as unwilling to go vegan as your uncle Frank. Try what you will, it’s just not going to happen. But with enough effort on your part, many cats will over time be willing to eat a 100-percent vegan diet.

Monitoring Your Vegan Cat’s Health

At the start of this article how I wrote that it’s exceedingly difficult to get your cat onto a vegan diet. Now that we’re halfway through, it must seem like I’ve exaggerated the total effort required. How hard is it, after all, to try a few different brands of vegan cat food or to experiment in the kitchen until you concoct a recipe your cat will accept?

The trouble is that getting your cat to eat a nutritionally balanced vegan diet is only half the job. And, worse yet, it is the (comparatively) fun and easy part. Because once your cat has become vegan, there is a second, less savory half of the job that must be performed. Are you ready? You’ve got to have your vet obtain samples of your cat’s urine for pH testing. I wish I was making this up, but it’s true.

Now why would you need to collect urine samples? Haven’t we already concluded that correctly formulated vegan food offers all the nutrients a cat needs? Sampling urine turns out to be an absolute necessity because vegan diets, even if nutritionally complete, tend to be more alkaline than diets that are based on meat. And since a cat’s urinary system is tuned for high acidity, there can be severe consequences if the alkalinity within the urinary tract gets out of hand. Even if your cat is getting all the nutrients he or she needs from a vegan diet, elevated alkalinity can lead to life-threatening—and expensive to treat—health problems.

Specifically, a vegan diet increases the risk of Feline Lower Urinary Tract Disease (FLUTD). A precursor to FLUTD is the formation of urinary struvite stones. These stones arise from either too much dietary magnesium or excessive urine alkalinity. Vegan cat food is unlikely to contain excessive magnesium, but it’s quite likely to increase urine alkalinity. Once struvite crystals form, they can block your cat’s urethra, making urination difficult or impossible. The required catheterization and hospitalization typically costs upwards of one thousand dollars. Without prompt veterinary treatment to deal with this blockage, a potentially infection can set in. Any cat can develop urinary crystals if put on an improper diet, but when males develop urinary crystals, the consequences are much more serious.

So for both karmic and financial reasons, it makes sense to do everything possible to ensure that these stones won’t form. The most reliable way to prevent struvite stones is to conduct urine tests. You must do a urine test two weeks after changing your cat’s diet. About 15 to 20 percent of vegan cats will develop FLUTD if they do not undergo proper urine tests.

Your cat’s urine test will reveal several important pieces of information. If the urine is found to contain bacteria, you’ll have a clear indication of a bladder infection requiring veterinary treatment. Likewise, the urine may contain crystals, which—if not treated—could lead to a bladder infection. And even if the urine contains no bacteria or crystals, an improper pH signals danger ahead.

If the urine is too alkaline (if the pH is above 6.5), acidifiers can be added to the diet. These acidifiers include methionine, vitamin C, and sodium bisulfate, and are discussed at length in Gillen’s books. Be sure to consult your vet before using a methionine supplement, since these can produce gastrointestinal problems or anemia. If you’re preparing cat food from scratch, rather than purchase an acidifier you might switch to a cat food recipe that contains naturally acidifying foods like asparagus, peas, brown rice, or oats.

Note that you should only resort to acidifiers or acidifying recipes if urine tests indicate a necessity to do so. You want your cat’s urine pH between 6.0 and 6.5. Unwarranted use of acidifiers can cause health problems— ironically enough, those wretched urinary tract stones again—in this case composed of calcium oxalate rather than struvite.

If you’re trying to correct urine pH levels through diet or supplements, you must keep bringing your cat in for testing every two weeks until the urine pH falls into a healthy range. Even after your cat’s urine hits a safe level of acidity, you must conduct tests on urine acidity every six months for the rest of your cat’s life. Maintaining proper urine acidity in vegan cats requires a delicate balance and vigilant checking. Anyone not willing to do the initial urine tests followed by twice-yearly follow-ups should not move ahead with putting a cat on a vegan diet. Each urine test will set you back at least sixty dollars, but that’s a pittance compared to the surgery and hospitalization costs that will arise should stones appear. More importantly, these tests can eliminate the suffering and life-threatening risks that arise from a blocked urethra.

When the urine pH is found to be in the healthy range, you can provide additional support for urinary tract health by encouraging your cat to drink plenty of water. One way to accomplish this is to provide two sources of water: plain water, and water flavored with vegan bouillon cubes. Many cats will drink extra water if it is provided by a flowing water fountain—these fountains can be purchased at many pet stores. Serving wet rather than dry food can also boost your cat’s water intake, although this may diminish your cat’s dental health.

Even if your cat’s urine tests indicate no cause for concern, urinary tract problems can still occur. Everyone who has a cat should therefore keep an eye on litter box behavior. If a cat shows signs of straining during urination and is lingering around the litter box, it could be a sign that the urinary tract has become blocked. Bring your cat to the vet right away if you see abnormal behavior around the litter box. The more time that passes, the more damage occurs, and the greater expense and complications. Being vigilant for meowing, straining, lingering, and frantic behavior at the litter box can prevent disaster.

As if convincing your cat to eat vegan food and then closely monitoring his or health were not enough, you’ve got one final thing to deal with when putting your cat on a vegan diet. You must tell your veterinarian about your cat’s diet, and your veterinarian probably won’t be any more enthusiastic about feline veganism than was your cat. This leads naturally to the temptation to keep your vet in the dark regarding your cat’s diet, but doing so would be a great mistake. If you’ve learned nothing from this article, it has hopefully been clear that vegan cats face a number of special health risks. If your veterinarian isn’t informed of your cat’s diet, he or she won’t know to look for early signs of trouble.

Should You or Shouldn’t You?

If you’ve done everything suggested here, then all you need to do over the long-term is to keep an eye on your cat’s coat, eyes, and overall behavior, as those things can offer the first indication that your animal’s health has diminished. There’s no doubt that many cats can thrive on a vegan diet long-term and that feeding vegan food to a cat deprives the meat industry of some revenue. What’s more, numerous reports exist of people who’ve switched to vegan cat food and found that their cats’ health actually improved. This is hardly surprising, given the vile ingredients that find their way into regular cat food. As long as your cat is happy eating nutritionally balanced vegan food, and urine pH levels stay within the normal range, it’s likely that vegan cat food is a cleaner and healthier choice than conventional food.

However, as we’ve seen throughout this chapter, putting your cat on a vegan diet takes considerable effort and expense. There are a few last things to consider when contemplating the switch.

The first is that no large corporation is yet manufacturing vegan cat food. Large companies tend to devote money to R&D and quality control that smaller companies cannot match. In consequence, there can be some risk to entrusting your cat’s health to a small manufacturer of vegan cat food—especially given the fact that cats require a specific balance of nutrients if they are to survive on a vegan diet.

One pet food company markets a vegan cat food that, by the company’s own admission, is nutritionally inadequate. Another company once had its vegan food tested by an independent laboratory, and the results indicated that several key nutrients were present at levels far below the label’s claim. More troubling still, in my opinion, this company did not act swiftly and decisively to rectify the situation. I find these cases troubling to say the least. Levels of taurine and other key nutrients are not to be trifled with, since your cat’s survival depends on properly formulated food. While it’s relatively inexpensive to ensure that your cat’s food is not creating an alkalinity problem, it’s much harder to test your cat for taurine and other possible deficiencies. When it comes to evaluating whether a given cat food’s nutrients match up with the claims on the label, you have no choice but to trust the word of your cat food or supplement manufacturer.

Having said all this, it’s not as though the companies that produce meat-based cat food are bastions of quality and integrity. For budget and mid-priced cat food, it’s common for a substantial portion of the food to be derived from slaughterhouse byproducts. This material may include some incredibly nasty stuff. Basically, if you feed your cat anything but premium cat food, you can be certain that your animal is eating rendered protein from flesh riddled with tumors, abscesses, or infected wounds. Basically, if an item is too disgusting to be allowed in a hot dog, it becomes pet food. In fact, cheaper cat food can even include animal protein of unspecified origin—which means your cat may be dining on the rendered flesh of dogs and cats killed at city shelters.

So, should vegans feel ethically obligated to put their cats on a vegan diet? Perhaps not. In making this analysis, I’m in no way seeking to belittle anyone who wants to make the attempt. Putting your cat on a vegan diet guarantees that not a penny of your cat’s food dollar goes to support factory farms and animal slaughter. But I also think it’s important that people understand that this effort doesn’t come close to delivering the biggest bang for the buck in terms of preventing farmed animal suffering. For one thing, between the added expense of commercial vegan food and the twice-yearly urine tests, you can count on spending at least an extra two hundred dollars each year to keep your cat on a vegan diet. Some of this expense can be cut away if you’re willing to prepare the food from scratch—assuming your cat will eat homemade food—but then it becomes your job to put in perhaps twelve hours a year preparing cat food. Many vegans may lack the time and money to make this commitment.

Donating that same two hundred dollars each year to an effective animal protection group probably yields a reduction of slaughter at least ten times greater than what switching one cat to a vegan diet will accomplish. And the two to twelve hours of time required each year to keep a cat healthy on this diet could instead be invested toward one form or another of animal protection activism, resulting in an even greater reduction of animal slaughter.

In the end, the decision to put your cat on a vegan diet will depend largely on three factors: your finances, your time, and your cat’s ability to stay healthy while cheerfully consuming the foods you provide. If any of these factors are lacking, there’s no need for despair. Just consider this an opportunity to channel your energy into avenues that make an even bigger difference for farmed animals.