Is tuna bad for cats?

Can cats eat tuna?

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.

Related Posts


  1. I can hardly believe that you are telling us that feed our cats with products that contain mostly fillers is better for them than 100% real fish.

  2. I have been feeding my 10 year old cat a small amount of tuna twice a day since she was a kitten with no problems at this time. Just had a full blood work panel done on her and all was very good. She is also fed a high quality dry food. Grain free and made in the USA. Her teeth are in very good shape too.

  3. My cat was 16 years old – We did feed her a tablespoon of canned tuna with her regular cat food and the vet said that was fine – or we could even give her the tuna water only the vet said (She didn’t like any oil) – There was no concern for mercury poisoning and I looked it up and studied it for quite a while – What did develop was hyperthyroidism – Some online details said the tuna or the cans it came in could have contributed to the hyperthyroidism – Tigger passed at 16 years old and I still don’t know if I could have done something different or even left it out of her diet even though she loved it so much : (

    • I am sorry to hear that Patti #2 cats do not live much more than that……..I have a friend who has three old ones…..they have lost all control of their bowels…..her house is a constant mess…but so is she………I know mine is in love with life as yours was…….trigger loved every day she had with you………you are a good mom……..sorry for your loss…..

  4. I am concerned my cat loves tuna…….she is 13 she does very well. mostly indoor cat she also gets treats and her dry food only two or three times a day a little tuna in water……she dearly loves it…..she is fine….should I worry…..other foods she licks the juice, and leaves the so called meat? I love to see her eat the fish………………meat…….protein……..

  5. I have been feeding my cat tuna and a high quality dry food. I would think real fish would be healthier for cats rather than typical wet cat food. The canned food has a lot of ingredients; Whereas tuna only has the fish. Not too sure about the health problems of the mercury in the tuna. Because cats are strict carnivores I would think fresh meat should be part of their normal diet; Just my opinion. My cat is 3 years old and free from any health issues.

  6. I have a 10 year old with kidney disease. He gets saline every other day, a kidney diet and a tuna flavored liquid medication. He hates the diet and liquid so I mix these in with a spoonful of tuna daily so that he will take the medicated food and liquid. If I didn’t then he would never eat the kidney food or take the liquid. Not sure if I’m doing more harm than good, but at least he’s taking the meds this way. Hopefully I’m not making this worse….

    • Julie, this isn’t on the topic of tuna, but I also have a kidney cat (diagnosed 6 1/2 years ago) and I’ve been giving him Azodyl almost the entire time, along with periodic saline as needed, and he eats regular canned cat food since he won’t touch the kidney food. Azodyl is a veterinary probiotic intended especially for cats & dogs with kidney failure, and it has helped him tremendously. He takes 3 capsules daily–2 a.m. & 1 p.m. Check it out online if you’re interested. It facilitates enteric dialysis–meaning that many of the toxins normally filtered by the kidneys are eliminated in the intestines instead via this probiotic. Not quite as efficient as the kidneys, but pretty close. It has worked really well for us. Just FYI.

  7. I have a burmese that eats dry food and seems to only want to eat “fish”; Applaws, states it all natural, Dolphin friendly, no additives, rice is added. My previous Burmese ate fresh raw steak, this one tried mince for a little bit, then i tried chicken. Although she has Science diet dry food available all day she eats minimal amounts and looks for something else occasionally. She a gets a tin 70g over two days at the most. Any suggestions on what else to try rather than “Fish”

    • Hi Wendy. A fish variety of cat food is fine. The concern is in regards to feeding large amounts of plain canned tuna which, on its own, is not a balanced diet.

  8. “wendy…SCIENCE DIET IS AWFUL FOR YOUR CAT and that is why she doesnt eat it. Cats are very smart and are as sensitive as humans. If they arent eating it then CHANGE BRANDS…They add sooo much garbage in these pet foods…do you KNOW what is going into them? READ THE LABELS and do the research,,then you will know why the cat doesnt want to eat it.

  9. My 7 year old Burmese is on a dry prescription food diet, but he recently developed a taste for tuna and since I’ve discovered that I can hide his daily heart pill in it (better than shoving a pill down his throat every day), I give him a table spoonful a day. He doesn’t like wet food (just licks the gravy off it), so perhaps I should find something of a similar texture that’s just as appealing so we can alternate.

  10. I have a 10 yr old boy and have wasted lots of money over the yrs, as he ll just walk past wet foods, some he used to eat.
    The one type he doesn’t pass up, is tuna flavors. Ill take my chances now. Hes 20 lbs, he’s on prescription dry, and to prevent him scratching or waking me up meowing for wet food, ill continue this tuna wet.
    If you have an HEB, try Fortis canned food – my boy loves that and cleans the plate. Plenty of times he’d lick only the juices up.

  11. I have a problem. My cat wont keep anything down except tuna! She is losing weight. Please help

    • I hope there has been an improvement. If your cat isnt eating enough, she will get hepatic lipidosis (skin will have a yellow tint & she will vomit bile). Catsure has helped my cat, but take her to the vet as it is a deadly condition. There are several options for treating this & getting her back to eatng normally.

  12. My past cat, Vanilla died from kidney failure. He ate can of tuna every day for 10 years. He loved it. He hate can of cat foods. So I stopped feed him with can of tuna. Then I feed him with special k-d food for 5 years. Vets told me that tuna was bad for cat. I wish I would not feed him can of tuna but he was stubborn. He always want to have can of tuna. I don’t feed my present cats with can of tuna. I feed him can of cat food with turkey and chicken. No tuna.

  13. My cat Baba was diagnosed with kidney disease 2 years ago. She would not eat the kidney food. So for the last 2 years she ate her regular dry food and tuna with water. She recently went to the vet for a check up and her blood work had returned to almost normal. The vet couldn’t believe it. The only thing different was the tuna with water. She will be 18 in January. So I take what is said about tuna with a grain of salt.

    • Thank you Laura! My cat eats tuna in spring water EVERY DAY FOR EVERY MEAL. He loves it and refuses to eat any type of wet cat food. He does eat regular dry Adult Original Science Diet cat food. We have had him now for 3 years and he is very healthy and active. We adopted him from a shelter, and he had been homeless, which is how I think he acquired the taste for tuna, as some people would have probably fed him that since he is very friendly. We think he’s about 4-5 years old now. I bought every possible brand and flavor of wet cat food at first, and he would not touch any of them! So now it’s white tuna in spring water only! With biscuits on the side. Surf & turf…

  14. My Husband insists on feeding our 17 r old cat(with kidney disease) tuna made with mayo and other additives. Usually from a tuna salad made at a restaurant. When I try to explain that this is not healthy for the cat. he gets upset at me. What are your thoughts about this practice.

Leave a Comment