Can cats eat tuna?

Can cats eat tuna every day?

No. Tuna is fine as a treat, but it shouldn’t be part of your cat’s daily diet. Plain tuna is high in protein and cats love it, but it lacks the balance of vitamins, minerals and fats a cat needs to stay healthy.

Vets usually recommend that treats make up no more than 10% of your cat’s daily calories. The rest should come from a complete and balanced cat food. Our cat calorie calculator can show you how many calories your cat needs.

Cats fed mainly tuna over weeks or months can develop nutritional problems, take in more mercury than is good for them and become so fond of the taste that they refuse anything else.

Is canned tuna safe for cats?

Plain canned tuna packed in water is the safest option. The problem is usually what the tuna is packed with.

Onion and garlic are toxic to cats in any form, including powder. They damage red blood cells and can cause anemia, sometimes days after eating. If your cat ate tuna seasoned with onion or garlic, call your vet. For a large amount, or if your cat seems weak or has pale gums, see our cat emergency guide.

Oil adds a lot of fat. It can trigger vomiting or loose stools and adds unneeded calories.

Brine is salt water. Too much salt isn’t good for any cat, and it’s a particular concern for cats with heart or kidney disease.

Raw tuna carries a risk of bacteria and parasites. Stick to cooked or canned.

Is the mercury in tuna a risk for cats?

Tuna is a large, long-lived fish, so it builds up more mercury than many smaller fish. The occasional treat isn’t a concern. The risk comes from feeding tuna often, over a long period.

According to FDA testing, albacore (“white”) tuna tends to contain more mercury than canned light tuna, which is mostly skipjack. If you share tuna, light tuna in water is the better pick.

Commercial cat foods made with tuna are generally considered safe, but rotating between fish and meat flavors is a sensible way to avoid feeding one fish all the time.

Can tuna cause thiamine or vitamin E deficiency in cats?

It can, if tuna makes up a large part of the diet.

Thiamine (vitamin B1) is essential for cats, and they need more of it than dogs do. Cats fed diets based heavily on fish, especially raw fish, can become thiamine deficient. Some raw fish contain an enzyme that breaks down thiamine, and it can also be lost during processing. Early signs include poor appetite and vomiting. Later, cats can develop wobbly walking, a head that bends down toward the chest, and seizures. Thiamine deficiency is a medical problem that needs a vet.

Vitamin E deficiency is the other classic risk. Tuna is rich in unsaturated fats, which use up vitamin E. Cats fed large amounts of tuna, particularly red tuna, can develop steatitis, sometimes called yellow fat disease. Body fat becomes inflamed and painful, and cats may have a fever, stop eating and dislike being touched.

Both problems are rare in cats eating a complete cat food with the odd tuna treat. They mostly show up in cats fed tuna meant for people as their main food.

Why do some cats get hooked on tuna?

Tuna has a strong smell and taste that many cats find irresistible. Some cats fed it often start holding out for tuna and turn down their regular food.

That’s more than a nuisance. A cat that refuses to eat for more than a day or two is at risk of hepatic lipidosis, a serious liver condition. If your cat has stopped eating, don’t wait for them to come around.

Tuna can be a handy way to tempt a sick cat or hide a pill, but ask your vet first. Some cats with kidney disease, allergies or other conditions need a special diet. Fish is also one of the more common food allergens in cats, so itchy skin or ongoing stomach upset after fish is worth mentioning to your vet.

How much tuna can I give my cat?

Keep it small. A teaspoon or two of flaked tuna in water, no more than once or twice a week, is a reasonable treat for an average adult cat. Count it within the 10% treat allowance.

Good ways to serve it:

• as a topper on a spoonful of their normal food
• as a reward during grooming, nail trims or carrier training
• frozen in tiny amounts in a lick mat for enrichment

Stop and call your vet if your cat vomits, has diarrhea or seems unwell after eating tuna.

Wondering about other human foods? See our is it safe for cats? guides.

Written by the CatsMed Team from the sources above. This guide isn’t reviewed by a veterinarian and isn’t a substitute for one. See how we research.