Should cats be vegans?

veterinary news

Seriously?  PETA is now urging people to feed their cats vegan diets.  This is a really dangerous statement and I am urging people not to listen to this advice!

You can read the article by Peta, here:

My main concern with the article is that there are zero research articles that support these claims.  Here are some quotes from the PETA article:

Many vegetarians and vegans feed healthful, meatless diets to their companion animals.

Sure…some people do try to make their pets vegetarians and vegans, but does this make it right?  Cats and dogs are carnivores – their bodies are designed to thrive on eating meat.

Studies have shown that the ailments associated with meat consumption in humans—such as allergies, various types of cancer, and kidney, heart, and bone problems—also affect many nonhumans.

If these studies exist, I’d like to see them.  PETA lists references at the bottom of their article, but most of them are personal anecdotes.  There are no research studies listed.

Should cats be vegans?

Raw meat - photo by n0nick of flickr

Some facts about cats and veganism:

The anatomy of a cat was created to thrive on a high protein diet.  I’ll describe below why the majority (if not all) of this protein needs to come from meat.

There are several factors that make it difficult for a cat to get energy from carbohydrate sources:

  • Cats don’t have the molars and premolars necessary for grinding up food.
  • Cats don’t have an enzyme called amylase in their saliva and have very little amylase in their intestines.  Amylase is necessary for breaking up starches.
  • Cats have a shorter digestive tract than most animals.
  • All of this together means that when a carbohydrate enters the digestive tract, it often will pass through without giving any benefit to the cat at all.  By the time the food gets through the intestines, the cat has been unable to digest it and get an energy benefit from it.
  • An increase in undigested carbohydrates in the intestines will change the bacterial flora.  This change in bacterial levels also interferes with the intestines’ ability to digest protein.
So now we understand that cats can’t thrive on a diet of mostly carbohydrates.  But, what about feeding a diet of vegan proteins?

About cats and protein:

We’ve established that cats need protein as the major component of their diet in order to survive.  Let’s talk about amino acids, which are the building blocks of protein.  There are several amino acids that are essential to a cat’s health.  And cats can’t produce these amino acids on their own – they need to be taken in in food:

  • Taurine – Cats who don’t get enough taurine are almost guaranteed to get a serious heart problem called dilated cardiomyopathy.  They can also have issues such as blindness and abortion.  Taurine is only found in animal protein.  Any taurine supplements that you can buy are made from animal protein and therefore would not be considered vegan.
  • Arginine – This is another amino acid that is only found in animal protein.  Deficiencies in arginine cause vomiting and possibly even coma and death.
  • Methionine and cystein – Deficiencies can cause skin problems and poor hair coats.
  • Tyrosin – A deficiency in tyrosin can cause black hair to turn reddish brown.
  • Arachidonate – Another amino acid that is only available from animal sources.  There is a form that can be derived from kelp but it is structurally different than the animal form.
Cats also need B12 which also comes from meat.  Many cats whose owners have attempted to feed them a meatless diet end up with copper deficiencies and sometimes imbalances in calcium and phosphorus levels.

If you REALLY want to feed your cat a vegan diet:

Some people want to make their pets vegan because of religious reasons or personal beliefs.  My advice to you would be to consider not having a pet.  It is unnatural to take a carnivore and ask them to eat a vegan diet.

I’ve focused on cats here.  It is possible to have a dog be a vegetarian.  (There is actually a prescription vegetarian food.)  This is because dogs need 2-3 times less protein than cats do.  I still don’t recommend making your dog a vegetarian or vegan, but if someone is adamant then I’ll recommend a prescription vegetarian dog food.  But there is no safe way to feed a cat a vegan diet.

If I had a client who insisted on feeding their cats a vegan diet, I would recommend the following:

  • Regular blood chemistry tests every 6-12 months.
  • Protein/creatinine levels done in the urine regularly
  • Regular chest radiographs to determine if the heart is becoming enlarged
  • Regular eye exams by a veterinary ophthalmologist

What do you think?

This is a controversial subject and in asking for comments I’m probably just asking for trouble!  I would love for someone to give me good scientific evidence that cats can thrive on a vegan diet.  (I don’t want to hear, “I fed my cat as a vegan and he lived for 34 years, so that’s proof”. )  If I ran a food company that sold vegan pet food I would be publishing studies that showed that my foods were not only safe, but even better than commercial foods.  I haven’t been able to find any studies like this.


Your thoughts?  (See the comments section below)



Bradshaw J, et al. Comp Biochem Physiol 1996;114A(3):205.
Berschneider H. Clin Tech Sm An Pract 2002;17(1):1.
Michel K. Vet Clin Small An 2006;369:1269.
Hoenig M, et al. Am J Phys Regul Integr Comp Phys 2007;292:R227.
Markwell P, et al. Nutr Reser 1995;15(1):53.
MacDonald M, et al. Ann Rev Nutr 1984;4:521.
Laflamme D. Vet Clin Small Anim 2005;35:71.
Laflamme D, et al. Intern J Appl Res Vet Med 2005;3(2):62.
Morris J, et al. Am Soc Nutr Sci J Nutr 2002;132:1648S.
Morris J Nutr Res Rev 2002;15:153.
Zoran D. Text Vet Int Med 2010;7:652.
Zoran D. JAVMA 2002;221(11):1559.
Larson A, et al. in Consult Fel Med 2010;6:127.
Kelley, L, ACVIM 2010, Why aren’t cats Vegans?


About the author

Dr. Marie

Dr. Marie is a veterinarian treating dogs, cats, and pocket pets. Click here to ask Dr. Marie a question.

Follow Dr. Marie on Twitter

Become a Fan of Dr. Marie on Facebook

9 Responses to "Should cats be vegans?"

  1. Emily says:

    I am not sure what to do. My sort of step dad, and his wife have taken my cat to france. they are vegan. They have decided to feed my cat vegan food. Apparently they put a lot of research into it, and put pills in it. Pills of taurine and vitamins and all that stuff you mentioned. I don’t know though if that is still okay. They say they prefer it to buiscuits. (duh!! Of course they do, warm wet food over dry biscuits that the smell will sttract better? duuuuh~) But yeah, my cat has lost a lot of weight. They don’t like going to vets and stuff much becuase all the needles and medicine and whotnot will be tested on animals. No idea what to do, but does putting the vitamins in pill form in the food make it right? x.x

    1. DrMarie says:

      I don’t believe that supplementing with vitamins is going to be the equivalent to feeding meat. Plus, most of the supplements are made from animal protein, so they wouldn’t be totally vegan.

    2. brenda says:

      Hi- I am a vegan and I live with two cats. My cats are both fed a grain free diet. One of my cats develops dry patches on her tail if I feed her any food or snacks with grains. She would attack these spots and make her tail bloody. Her condition was so severe that the vet felt it was FHS .
      In an effort to get to the bottom of what was happening to her I “journaled” those foods that precipitated her attacking her tail. I tried a variety of high quality canned foods but the problem persisted. It was not until I switched her dry food to a grain free diet that her coat become glossy and her entire demeanor changed. My elderly cat who had a hard time putting on weight gained 3lbs and both are looking amazing since I have gotten the grain out of their diets.

      This did not surprise me too much as cats are carnivores and grains really should not play a part in their diet. Out of responsibility to my allergy prone cat and out of responsibility to both my cats as carnivores I feed them a premium diet for carnivores. That consists of meat.

      I feel my cats did not ask to live with me and I owe it to them to meet their needs, anything less would be cruel. They cannot help that they are a species that needs meat to survive. They are an integral part of the world just as any other species. We must respect them for what they are.

      As a human I do not need meat to survive so when I eat or purchase clothes or other products I make sure that no animals were harmed to provide me with anything from sustenance to entertainment. As a human I do not have to harm another species to survive.

      Some might argue as to why then do we feed our cats beef as opposed to rodent meat. Its simply not feasible. Besides killing mice is no less cruel than killing cows or chickens, all are sentient beings. Its also not feasible for domestic cats to hunt for their own food to survive.

      Some might say that we should not share our homes with cats so that we are not responsible for feeding a carnivore and state that this is an unnatural relationship imposed on the animal by humans. I say that this is another unrealistic notion and that to rid ourselves of this connection we would have to get into a time machine, perhaps back to the neolithic era, to the day cats began their relationships with us.

      Domestic cats are now animals reliant on humans for optimum living conditions. They live linger and better lives when they are in our care. Their choice to thrive as wild animals was taken from them a long time ago. We owe it to them to feed and care for them properly and this involves feeding them the food they need to thrive.

      It is sad that other animals need to suffer for pets like cats to eat but it is not preventable. Animals do not need to suffer to feed humans and in this lies the reason I feed my pets meat but do not consume animal food items or use animal derived or tested products.

  2. K. says:

    I am vegan and am sick of this crap! I have deleted many vegan friends off of Facebook for this very reason.Don’t be stupid get your dog and cat normal dog and cat food it’s not like you have to touch the meat yourself! Listen if you are not going to put your own animal first then don’t bother getting a carnivorous animal get a bunny rabbit!

    1. casey says:

      I totally agree, its so selfish for vegans to get a dog or cat as a pet, knowing it is a carnivore by nature, then forcing it to give up its natural diet for one that is non natural. Humans are omnivores, and can handle eating only plant products, cats and dogs have sharp teeth for a reason, its defnitely not for tearing plant leaves thats for sure. Get a horse, sheep, cow, rabbit or other herbivore if having a carnivore bothers you. Making an anumal eat an unnatural diet is like expecting humans to eat dirt and get all their nutrients from it and it only.

    2. J says:

      THANK YOU! It’s nice to hear an intelligent person that understands that our pets have different dietary needs than people do. 🙂

  3. Jim Jozwiak says:

    This is mostly excellent information. However, arachidonate refers to the essential fatty acid 20:4 n-6 and is not an amino acid or protein.

  4. Barry Appleby says:

    If vegans are truly against any and every form of human oppression of non-human species, then logically they have no right to impose their own views on their own pets, who have no say in the matter and are being used by vegans as test animals when they are fed food that is designed to conform with an ideological standpoint and not the animals’ nutritional needs.

  5. Ruth says:

    Sorry folks but the proof of the pudding is in the tasting as they say. I have lived with and know many people who have thriving beautiful vegan cats and these cats are around 10 years old now and look like a young cat, never need vet visits for bad health. I think you need to understand this equation- Newton’s Law of Motion : “To every action there is always an equal and contrary reaction; the mutual actions of any two bodies are always equal and oppositely directed.” Action and reaction are thus exactly equal. “To have a single force is impossible. There must be, and always is, a pair of forces equal and opposite.” Any time someone pays for an animal to be killed for them (buying pet food or a baby cow or sheep) to eat or for their pets, you end up with this equation Violence = Violence The violence of killing a cow for example is returned (equal and opposite reaction) in the form of ill health, accident, loss etc it could happen anytime after the first act of violence and come in any number of ways, but one thing is sure, IT WILL COME!!! AS the song says “You only get what you give” It works like gravity, even if you dont beleive in gravity it still affects you. This is a scientific fact that Mr Newton discovered and it applies to ALL physical matter. That is why we are taught from a wee kid to do good and be nice because thats what we get in return. Wake up people, use your logic you cannot create good health from a viloent act and killing is ALWAYS violent!

Leave a Reply

IMPORTANT: Dr. Marie does not answer questions about your pets in the comments section. Click here to ask a vet about your pet.

Ask A Vet

Stay up to date!

Receive each veterinary news story by email.

Enter your email address:

We value your privacy!

Easy unsubscribe at any time.

All content © Ask A Vet Question