Food safety
Can Cats Eat Tuna? As a Small Treat, Not Every Day
Yes, in moderation: a little plain tuna is safe for most cats as an occasional treat, but it should never become their regular food. Tuna canned for people is not nutritionally complete for cats, and the Merck Veterinary Manual notes that commercial fish products such as tuna have caused long-term mercury poisoning in cats. Choose tuna packed in water, with no salt, oil or seasoning, and give a teaspoon or two at a time.
By Matt GarnettUpdated November 13, 20264 min read2 sources
Why tuna works as a treat but not as a diet
Cats are obligate carnivores, and plain tuna is a meaty, high-protein food most of them adore. The problem is balance. Tuna made for people lacks the full range of vitamins and minerals a cat needs, and Cornell's Feline Health Center warns that some cats fed canned fish products meant for humans developed potentially serious neurological disorders.
Tuna also has a strong smell and flavor that can make ordinary cat food seem dull. A cat that gets tuna often may hold out for it and eat less of its complete diet, which is how a treat slowly turns into an unbalanced menu.
Mercury, salt and oil
Large predatory fish build up mercury over their lives. The Merck Veterinary Manual states that tuna products have caused long-term mercury poisoning in cats, with signs that include hind-leg stiffness, lack of coordination and tremors, and that neurological damage may be irreversible. Occasional small amounts are not the concern; frequent, large servings are.
How the tuna is packed matters too. Tuna in oil is much fattier and can cause vomiting or diarrhea. Tuna in brine adds a lot of salt. Flavored pouches may include onion or garlic, which are unsafe for cats. Plain tuna in spring water is the only kind worth sharing.
How to serve tuna to your cat
Open a can of tuna in water, drain it well and flake a small portion with a fork, checking for any bones in fresh or home-cooked fish. Serve it on its own or as a little topper on your cat's usual food.
If you cook fresh tuna, cook it all the way through with no seasoning. Raw fish carries a risk of bacteria and parasites, and Cornell does not recommend raw diets for cats. Tuna sushi and sashimi made for people should not be shared.
Many cats do better with small, slow portions, and a puzzle feeder or a slow feeder bowl helps with both.
How much tuna can a cat have?
A teaspoon to a tablespoon of drained, plain tuna is a reasonable treat for an average adult cat, offered once or twice a week. Cornell suggests treats stay under 10 to 15 percent of a cat's daily calories, so the complete diet still covers everything a cat needs.
Cat foods made with tuna and labeled complete and balanced are a different product, formulated with added nutrients. If your cat eats those, there is no need to add people tuna on top. Cats with kidney disease or on a prescription diet should not have extras without a vet's approval.
Kittens and tuna
Kittens grow fast and need a complete kitten food to support that growth. Filling a small stomach with tuna takes the place of the nutrients a kitten needs most, and strong-tasting foods early in life can set up a picky eater.
A tiny taste of plain, drained tuna in water is fine once a kitten is on solid food, but keep it to a fingertip amount and not every day. Never use tuna as a substitute for kitten food or formula.
Signs tuna disagreed with your cat, and when to call a vet
Too much tuna, or tuna in oil, can cause vomiting, soft stools or a greasy coat within a few hours to a day. If that happens, stop the tuna, offer water and return to your cat's normal food.
Call your vet if your cat has repeated vomiting, diarrhea lasting more than a day, or refuses its normal food for more than 24 hours. Call promptly for any wobbliness, tremors, trouble walking or changes in vision or behavior, especially in a cat that has eaten a lot of tuna over time.
Better ways to treat a fish-loving cat
Rotate the treats. Small pieces of plain cooked salmon, cod or other white fish, plain cooked chicken or turkey, or a cat treat made with fish all satisfy the craving without leaning on tuna every time.
A spoonful of a complete wet cat food in a fish flavor can also be used as a reward, since it is formulated for cats. Keep the tuna for a once-in-a-while moment rather than a habit.
This page is general information, not veterinary advice, and it cannot replace an examination by the vet who knows your pet.
Common questions
Can cats eat canned tuna in oil?
It is better to avoid it. Tuna in oil is much fattier than tuna in water and can cause vomiting or diarrhea. If your cat had a little, watch for stomach upset and choose water-packed tuna next time.
Can cats eat tuna every day?
No. Daily tuna can unbalance a cat's diet and, over time, add to mercury exposure. Keep plain tuna to once or twice a week in small amounts, or use a complete cat food made with tuna instead.
Can cats drink tuna water?
A small splash of the water from tuna canned in spring water is usually fine and can tempt a cat to drink. Avoid brine, which is salty, and oil, which is fatty, and do not let it replace fresh water.
Can cats eat raw tuna?
Raw fish can carry bacteria and parasites, and Cornell does not recommend raw diets for cats. Cook fresh tuna through with no seasoning, or use plain canned tuna in water, and share only a small amount.
Is tuna cat food the same as canned tuna for people?
No. Cat food made with tuna and labeled complete and balanced has added vitamins and minerals cats need. Tuna for people does not, which is why it works only as an occasional treat.
Sources we checked
This guide is general information, not veterinary advice. If your pet is unwell or injured, contact your veterinarian.
