Is Tuna Bad For Cats?

Cats love seafood, and most cats are especially fond of canned tuna and tuna juice. While tuna is fine for cats in moderation or as a treat, too much canned tuna can be bad for your cat. Fish is a great source of protein, but there are a few reasons why a steady diet of human-grade canned tuna can cause health problems for your cat.

Tuna alone is not nutritionally complete, and many cats are allergic to fish. Most fish contain trace amounts of mercury, and the higher up on the food chain a fish is, the more mercury is accumulated in the fish. Tuna is relatively high on the food chain and therefore contains higher amounts of mercury than other fish, leading to an increased risk of mercury poisoning.

Tuna is also high in unsaturated fats.  While it is healthy for humans to choose unsaturated fats in their diet, too much can be bad for cats. Consuming too much tuna can cause your cat to develop a Vitamin E deficiency, leading to an inflammation of the fatty tissue, a condition known as steatitis (“yellow fat disease”).  Cats that consume large amounts of red tuna in particular are more prone to this painful condition.

Commercial canned “tuna” cat foods are not just straight tuna, but have other added ingredients, vitamins and minerals as well as the amino acid taurine, which is essential to cats.  Just make sure to feed your cat a high-quality pet food formulated for cats, and if you choose to feed your cat human-grade canned tuna, limit it to an occasional treat.

About author

Abby Rosenberg

Abby Rosenberg is a PetMeds employee and long-time cat lover. She was a volunteer for several years at a local no-kill cats only rescue shelter. This has prepared her for her most challenging role to date: secretary, photographer, social coordinator and treat dispenser for Daisy, and Daisy’s sidekick Harley. Daisy is a dilute calico Devon Rex cat, and Harley is a “cow-cat” who was adopted from the shelter where Abby volunteered. You can also find Abby on Google+

There are 43 comments

  • Susan Hernandez says:

    I feed my cat a couple of ounces of tuna a day as a treat (1 ounce in the morning and 1 in the evening). She still eats her regular cat food also. She seems to be doing fine. She is a 2 1/2 year old Tabby that weighs 9.6 pounds!

  • Trevor Lowe says:

    I agree with Susan, I’ve got 2 rescued cats that share about 1/3 can of Tuna in water daily. They would attack and kill me in my sleep if they stopped getting it. I’ve had them both for over a year, and they are very healthy. Keep in mind, they eat cat food 98% of the time. The tuna is just an evening treat.

  • […] to feed cats human tuna. Google it. You'll find all kinds of information on feeding tuna to cats. googletag.display('div-gpt-ad-1364420449836-3'); __________________ Honor Student: School of […]

  • Mom says:

    Cats can become addicted to human grade tuna. It should be given as a weekly or less treat.

  • Russell says:

    I opened a can of tuna for my lunch today and my cat came running from the bedroom. He smelled it 45 feet from the kitchen and was just talking up a storm.So I gave him about 1/4 of the can and now he seems very lathargic. Getting on my lap and now sleeping on MY pillow. Please tell me I didn’t make my cat sick. I’m still paying off his $430.00 dental bill.

  • Mark Brennan says:

    Hi Russell,

    I’m sure your cat is fine. I have been feeding one of mine tuna 2 or 3 times a week for the last 12 years and she is fine :)

  • LDV says:

    I have a 12 year old cat that I have given tuna reats (1/2 tsp of tuna) am every day for his life. He eats Purina cat food for his meals. I have increased the treats lately to pm as well and have noticed he has been in pain and has been having urinary spasms. Its not easy to notice…most cats are silent sufferers. I took him to the vet and they told me he has crystals in his urine. for the last two months I have had him on antibiotics, anti-inflammatorys, and a decrystalizer of some sort…Its like torture to him. I love my cat to be happy but I won’t sacrifice his health for a simple treat…we’ll find something else special. Thanks for the input.

  • Robin says:

    The idea that a cat who is being fed canned tuna frequently (weekly or more) is “fine” is a misunderstanding of the health problems associated with tuna. The heavy metals accumulate in the liver, thyroid, pancreas and kidneys, and destroy the digestive system, causing issues that a owner may not see symptoms from for awhile. Please don’t be stubborn by continuing to feed your pet anything toxic, just because there are no immediate symptoms. You are shortening your pet’s life.

  • Dawn says:

    I give my cats tuna and now one is very sick with digestive problems. I believe it is from eating tuna. I am not giving them tuna anymore.

  • kim says:

    with the Fukishima nuclear disaster the food chain is contaminated with radioactivity.
    It accumulates in phytoplankton /seaweed and works it’s way up the ocean food chain.
    It is already found in fish. It will soon work its way into many, many ocean products.

  • Mectu says:

    Hello everyone. The lead answer to this question is four and a half out of five stars. As for the other posts, some good, but most notably the one mentioning the nuclear accident in Japan. Please resist the urge to expound on the basis of ignorance. When there are science related issues, best to just listen if you are not knowledgable. 43% of US electrical power needs are met by hundreds of coal burning plants nationwide. Each plant burns the equivalent of a fifty car trainload of coal a day. Coal is about one to two percent uranium, thorium and plutonium. When coal is burned, these radioactive substances are released in the form of tiny particulate matter, which is fed into the atmosphere. The combined output of the world’s coal plants, mostly ours and China, puts approximately 15 thousand tons of radioactive material into the air EACH YEAR. The total amount of radioactive material released by all the nuclear accidents in history amounts to a few grams. This huge dump of radiation every day is because nuclear no nothings have stopped building of nuclear plants, and the only workable alternative (one we can use today, rather than talk about it and research it) is coal, which ironically puts as much radioactive material into the air as twenty thousand of your average car made entirely out of thorium, uranium and plutonium each year, which I believe accounts for many of our health problems. It is truly frightening what a small group of individuals, capitalizing on the fear and ignorance of people can do to make everything harder for everyone else, but that is exactly what the no nothing anti-nuclear activists have done. The Japanese power plant was less than one day’s output from the coal plants. Here endeth the lesson. To learn more, from one of our nation’s leading scientific minds, put “Dr. Bill Wattenburg” into your browser, and go to his site. Good day, and careful what you post.

  • Derek says:

    I love how there is a page devoted to the reasons why a certain food is bad for your cat yet immediately after there is a bunch of comments that say things like, “… well I’m feeding fluffy foo foo and she’s fine.” She won’t be fine when she ends up in the vet hospital. Then you’ll be blaming something else for the problem when it was your own stupid fault.

  • Cjay says:

    I just got 2 cats that are 1 year old on valentines day I ran out of their food and I have them a can of tuna to share I’m wondering if that can be harmful to them if it was 1 can between the two of them?

  • dpprice says:

    I have a cat that has inflammatory gum decease and can’t be given pills orally ….. it has to be crushed up and hidden in a very small amount of tuna every night and I was concerned about feeding her tuna as well. I guess it’s a catch 22 for using tuna as a means of administering medicine.

  • CB says:

    I’m reading comments here. When I hit a cash flow snag during a caregiver phase, I fed my cat human canned tuna. Within days – not making the connection immediately I noticed \Wow! What is with her fur- it feels like silk!!!!\ Then I started thinking back to any recent changes. Other than a minor other change of someone visiting less often, the only other change was the human tuna vs canned tuna.

    I’ve continued giving her some human tuna.
    Where I am going with this is I think I’m looking into making her own food and getting pet food recipes. There is something quality – wise I think in the higher grade tuna meant for people.

    With this said – I trust the Vet. So I’ll need to limit consumption.
    But otherwise she cries for soft food ( before the human tuna experiment), but leaves / wastes half.
    Human tuna she craves and wants more and more.

    I suspect maybe the question us the same as for people- \Do you enjoy quality of life and maybe lose a year or two — or do you eat right every day and maybe live to an old age?\
    Individual choice.

    Balance for me and my little one is important. And she sure loves her tuna – and her fur is proof.
    It’s absolutely beautiful! Shiny- silky- just a wow !

  • RicRah says:

    My cat Mr. Tibbs loves canned tuna, I ran out of regular cat food, and I only gave him half a can ( 16 lb cat so he’s pretty big – not fat just big ) although I did get very nervous feeding it to him because I know that you are not supposed to give cats onions, and unfortunately, canned human tuna is sopping with vegetable broth 90% of the time unless you are lucky enough to find ones that aren’t in your health food sections, and even then, most are. The issue is that vegetable broth almost always contains onions, and cats can get very sick from onions ( or garlic, chives, shallots, those bulb veggies ) it is known to cause anaemia and if too much is given, the cat could be lethargic, appear to have breathing problems or have vomiting or diarrhea, so please be cautious feeding human cat food! I used to put chicken broth in his water all the time, just a drop to make him hydrate more, and I stopped doing that for the same reason, I just didn’t realize how toxic those bulb veggies can actually be for the cats

  • douglas says:

    As George Burns always said “everything in moderation”. My cats are 9 & 10 years old and I have fed them canned tuna since they were kittens, but only off and on, never as a sold diet. My kitties are quite spry for their age and so from a decade of tuna feeding i say its ok (unless in the case of allergies) to treat them once in a while. Finally to the dipwad who wrote the 900 line article about power plants, this is about feline diet not your vaaaaast knowledge of environment. Kitties rule!

  • seth says:

    My cat passed 18 and he’s still in good health, mobile and eats about 1/2 can human grade yellow fin tuna every day (amongst other things). He’s not fat, never has been. The vet said that I should stop giving him tuna at the age of 8 (i.e., a decade ago) because it’d kill him due to his “failing kidneys” (high protein, phosphate and all these BS). He vent on a weeklong hunger strike, I gave in and he keeps getting his tuna ever since. Though his azotemia got worse over the past decade, he’s still not anaemic, still eats well and still seems happy; – as long as I don’t make changes to his normal diet. BTW, he always refused to eat the cat-specific tuna and most cat-specific seafood preparations. Either he’s a miracle cat or, perhaps, the cat-specific tuna/seafood is not so good for cats after all.

  • Pris K says:

    Im glad I found this , I either give my cat raw chicken as a nightly treat or a teaspoon of canned albacore tuna. I was wondering about the sodium content in canned tuna maybe not being good, but never thought about the mercury or other things that might be harmful.

    I give her a third of a cup to a half a cup of dry grain free cat food daily and lamb lungs as a treat.

    I will stop giving her the tuna and buy her some canned grain free cat food instead.


  • Bill B says:

    Is there any actual science or scientific studies that prove that canned tuna without added ingredients is bad for a cat, or is everything anecdotal comments about THEIR cat, old wives tales, or “professional” biased opinion? I am searching for actual science on the internet, but only find discussions like this. I don’t have a problem listening to actual evidence, but this opinion trading is just annoying. With Blue Buffalo at $1.49 a can and chunk light tuna at $.68, why not just use $.45 a can of shredded tuna Friskies? Tuna cat food is made from the same tuna (or worse) that goes into tuna cat food, so arguments about mercury, or radiation would be just as valid for tuna cat food as regular human canned tuna. I could see the issue of Taurine deficiency if you only fed canned tuna and nothing else, but a lack of Taurine would not HARM your cat per se, it only means that the cat would need to get that ingredient from another source. Does anyone have any science?

  • Eliz says:

    I have a one year old kitty. She’s small type but I know she needs more weight on her. Can someone help me put noticeable weight on her quickly. I wonder if it makes her feel bad. Also can someone tell me, how often do you feed your cats. I feed mine twice a day. Thanks!!

  • SmartyCat says:

    I gave my mother a kitten a month ago and aside from about 6-8 cans of special kitten food the lil’ pooper has been getting people canned tuna (with vegetable broth) because she (and I) believed it was a higher quality food. I’m glad I decided to see what else would benefit a kitten’s growth and health because canned tuna contains vegetable broth which contains onions and onions are toxic to cat’s blood, as I understand it. The kitten is far from anemic, in fact we should all wish for his energy and strength, but whether he likes it or not he’s going to have to eat cat tuna, or other canned cat foods. And earlier I learned that the worst canned cat food is better for pussy than the best kibbles. Unless the canned cat food is made overseas then all bets are off.

  • Dennis says:

    I also give my 3 cats tuna, they share 1 can each day, and I leave them dry cat food to eat during the day with water. They don’t like the regular cat food in the can, they would never eat it, so I had to look for another alternative. They are doing fine.

  • deidre ferrentino says:

    I was giving my 12 year old cat twice a day just a drop of tuna in a can amount less than
    a size of a dime, and never had a problem, however the Vet said NO TUNA SO I STOPPED
    as I did not want her to get sick or have a problem, just eats Royal Canin Duck and Venesion
    dry food at $61.00 a bag, I mix them together and that is all she has ever eaten. I give her
    the hyperallergent food as 1 vet said she has allergies. I must have a RX for this food.
    She looks for this Tuna every day and does not stop, I tried other treats and she will not touch
    anything. Do you feel NO OR NEVER TUNA? Thank You

  • luna says:

    mother fed her cat human tuna everyday; a 1/2 can. kitty lived to be 16 yrs old

  • Poki says:

    I have 2 male cats that have had the crystalline disease. I believe their diet of fish and tuna were the major precursors for this disease. I now NEVER feed either of these foods to my cats, especially males. My vet suggested Whiskas dry instead of high-priced vet food and no fish product canned food. I found 1/8th cup with 1 tsp with a bit of warm water to make a gravy a good diet morning and evening. My young boy stayed slim and my older guy lost weight. After episodes of the crystalline disease before this diet I had no problems afterwards.

  • Victoria says:

    i have a 1 yr old male rescue sweetie kitty who is the picky-est (don’t know if that’s a word) eater of any cat I’ve ever had. I don’t want to hurt him but I also know he refuses to eat what he doesn’t want. He’s gone from only canned, (for a couple of months) to refusing canned. He ate Meow Mix for a couple of months – leaving me with 3 other brands of dry food he refused. For 3 or 4 weeks he would only eat boiled chicken. Now he’s back to canned food but only if I put a little tuna and tuna water with it.
    I REALLY don’t try to spoil him but by the third -fourth day of not eating anything I’ll do just about anything to get him to eat. Any suggestions? He’s been to the vet and is healthy but (not surprisingly) a bit underweight. I’m at my wits end trying to figure why he’ll eat something fine for a while then refuse it and give me that CAT look – you know the one! That says “mom, you don’t think I’m going to eat that, do you!?
    You can guess how precious this little love bug is to me and I’d hate myself if he got sick because of what I feed him. Help?
    By the way, strictly a house kitty, there are mutant large raccoons in my neighborhood that he wouldn’t know how to deal with on their turf.
    Thank you for any info you can offer.

  • richardmoderate says:

    i gave my 2 year old adopted cat Lana some tuna in water-and now ( of course) she craves it-she eats her dry food which shes been getting since i first adopted her 1 year and a half ago-so i feel she is not missing any essential nutrition-but this discussion about weather some tuna or any tuna is bad for cats does have me worried now-i was limiting it to only 2 tablespoons every other day -but now i have stopped until i can get a clear yes or no on weather this “treat” is causing her harm or not-is 2 tbs of tuna in water too much for her??? i would really apreciate a firm answer-she is my dear companion and i DO want her to be able to grow old with me

  • goatboy says:

    I like to give my cats the tuna water. I don’t give them it that much and I usually have to put water in it since I have six cats that want in on the tuna juice. It’s not an everyday thing just a passing treat. Is the water still bad for them?

  • dash2007 says:

    I have been feeding my 7 year old male desexed cat human grade tinned tuna (with a cup of dry food on the side) for about a year or so. He had gradually refused to eat pet tin food, esp anything with beef. I tried to change to different brands but with no result. He loved the human tin tuna and I had no idea it was bad for him, as I was feeding him dry food which he was eating. He developed a chronic skin allergy which has cost me a fortune in vet bills. He is now recovered through the use of an elimination diet called Hills ZD. He has been on this for 10 weeks and I am about to re-introduce him to new food. He is starting to turn his nose up at it anyway. I am reluctant to put him on any standard pet foods as he might be allergic to additives in them. Any ideas?

  • L says:

    I am really worried about everyone who says they feed their cat tuna and they seem fine! Please keep in mind that you can’t always tell/it might not affect them right away, but it is still extremely risky and PROVEN to be poisonous for them

  • Ann says:

    I believe in everything in moderation. Even for us humans. Today’s food that is bad for us is good for us tomorrow. They can’t seem to get it right in the media so go with best gut instincts. Let your cat enjoy some life.

  • amy says:

    I’ve been giving my cat tuna for cats almost everyday and noticed she’s been gaining weight. She eats her regular food as well but I think it makes her sleepy afterwards. She’s an older cat too and don’t want her to be bothered with a lot of extra weight so it will be once or twice a week now. Thanks!

  • Dee says:

    It says do not do it and it states the reasons why. I can imagine that those of you continuing to feed tuna to your cats really don’t care about their health.

  • Bruce P says:

    We fed our cat “Chicken of the Sea” canned tuna EXCLUSIVELY for about 12 years. He was very healthy until the end when he passed away at the age of 21 years. We had a big 20th birthday party for him, see this
    What I’ve read, that a tuna diet might not be so great, seems to make sense, though we didn’t know that at the time. But it certainly didn’t hurt our cat’s health as far as I can tell. He had a very good and healthy 21 year life.

  • Joyce says:

    My vet does not want me to feed my cat canned tuna so that is good enough for me. I feed my cat cat food.

  • Melissa says:

    My elderly cat has never eating anything other than dry Chicken Soup for the Cat Lover’s Soul (which is a high quality grain-free natural cat food) and freeze-dried salmon as the occasional treat. He has refused canned cat food all his life, and I’ve tried every brand, consistency, and flavor. He started refusing his dry food and losing weight, which my vet diagnosed as a severe hairball that was clogging his digestive tract. After treating it and getting his system cleaned out, he never gained the weight back. He still barely eats. I discovered one day there is something he will eat, and that’s canned tuna and salmon. He goes crazy for it, cries and begs for it. I’ve never seen him so excited about food! He is regaining energy and is happy again. If I have to choose between watching my cat waste away to nothing and eating tuna, I’ll feed him tuna.

  • CKidd256 says:

    The level of ASH in dry cat food will cause the crystals in male cats. Find a lower ash content food. I learned this the hard way when my male cat developed the problem and my vet told me it was the food I was feeding at the time.

    I came here since it says “petmeds”, I was looking for real information on the subject matter. I wanted to see if tuna was safe enuf to give my a little bit on occasion. I will trust my own judgement and limit her intake.

  • Margaret C says:

    I had my Persian Romeo eat nothing but 9-Lives Tuna w/egg or Tuna w/cheese plus Science Diet dry food, and he lived to be 17 years old! There was a time a few years back when there was a problem in processing and I could not find it (had friends from other States send some) so looking at ALL the other cat tunas and reading the ingredients was scary to say the least!! If you read the ingredients in the 9 lives brand you will find Tuna, water for processing and all vitamins!! Nothing else. My Vet was amazed that Romeo lived such a long healthy life! I never fed him our tuna.

  • Lynda V says:

    Thanks for the advice. My cat won’t be getting any more human grade tuna from now on.

  • Muffy01 Bill B says:

    My Kitten Muffy who is a female, ets 9 lives Tuna and Egg and nothing more. She will eat straight tuna, but has eat 9 lives since she was 7 weeks old. I have tried to take her off of 9 lives and now i bye 4 can containers from Wal-Mart. i have done this for the past 1.5 weeks with giving her Tuna. I have been told that family dollar doesn’t sell 9 lives tuna and egg any longer but i went to Wally World last week and found it on the cat food shelf. I want to get her off the fish kick with tuna and egg and tuna because i have known for a long time that fish isn’t good for cats let alone a kitten. My older two cats i lost last year both to cancers, only had raw human tuna on there birthday, christmas and thanksgiving. I feed them purina dry food products , and canned food but no fish products. because of some of my research on what is good and bad for cats to eat that is why i did not feed them fish products. I want to get my kittens off of raw tune and 9 lives tuna and egg , does anyone have any idea how i can do this for her to eat other products so i kill my kitten and hurt her at all. thank you and i hope to hear from someone soon with a diet for Muffy. She does eat Purina kitten dry.

  • Tor Rognmo says:

    My cat pumpkin is a picky eater who refuses to touch any of the available wet catfood (those that quickly stink out your kitchen) and she’ll only eat the dry stuff if she has had nothing to eat for several days.
    However she absolutely loves human grade tuna and has been getting a three ounce can of that daily for the last year.
    When I started giving her that I did some research and the information I found indicated that the tuna used for canning was the smaller fish which had very little mercury accumulated, as compared to larger tuna used for tuna steaks, which can be high in mercury.
    Now I am a bit confused as to how to proceed as I have not yet found a commercial grade wet cat food that she is willing to eat and she does need to eat.

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