Can Cats Eat Tuna? Safe Amounts, Best Types and Real Risks

Can cats eat tuna? Yes, but only a little and not often. Plain, cooked tuna packed in water is safe as an occasional treat for adult cats. PetMD suggests no more than about 1 tablespoon once a week. Fed often, human tuna can lead to mercury build-up, vitamin E problems and an unbalanced diet.

Below we cover which kinds of canned tuna are safe, how much to give, and what to watch for. We also explain why tuna cat food is a different story.

If you are building a homemade diet, also read our guide to taurine for cats.

Is Tuna a Safe Treat for Cats?

A small amount of plain, cooked tuna is generally safe for healthy adult cats. According to PetMD, in an article by veterinarian Sandra C. Mitchell, DVM, tuna in small amounts is a safe and nutritious treat.

The problem is quantity, because human tuna is not a complete diet for cats. Also, some cats start to hold out for tuna and turn down their regular food.

So the honest answer to "can cats eat tuna" depends on three things: the type, the amount and how often. Get those right, and tuna can be a fun extra.

Why cats love tuna so much

Tuna has a strong smell and a rich, meaty taste, so it grabs attention fast. Cats are obligate carnivores, as Cornell explains, so they rely on nutrients found only in animal foods. That is one reason fish appeals to them.

That is why owners so often ask, can cats eat tuna at all? However, a strong appeal does not make a food complete. Tuna lacks the full balance of vitamins and minerals that cats need every day.

Tuna in Water, Oil or Brine: Which Can Cats Eat?

Not all canned tuna is equal, so use this table before you open a can for your cat.

PetMD advises canned tuna packed in water, not oil, with no added spices or flavors. In addition, the ASPCA warns that too much salt can cause thirst, vomiting and diarrhea in pets.

Albacore vs Light Tuna: Mercury Compared

When people ask "can cats eat tuna", mercury is the main worry. PetMD notes that tuna is high in mercury, especially albacore. So the type of tuna matters as much as the amount.

The U.S. Food and Drug Administration tracks average mercury levels in fish. Here is how common choices compare.

The FDA also notes that albacore typically has about three times more mercury than canned light tuna, as its fish advice for families explains. Those guidelines are for people. Still, the same ranking helps you pick a safer fish for your cat. So can cats eat tuna of any kind? Light tuna is the safer pick.

How Much Tuna Can a Cat Eat?

PetMD advises no more than about 1 tablespoon of plain, cooked tuna once a week for an adult cat. That is a small amount, so think of it as a topper rather than a meal. So, can cats eat tuna every week? Yes, in that small amount.

Treat calories add up

Cornell advises that treats should not exceed 10 to 15 percent of a cat's daily calories. Similarly, the WSAVA Global Nutrition Committee suggests that foods not labeled complete make up 10% or less of the diet.

Tuna also adds calories, and PetMD lists weight gain as one risk. So if your cat gets tuna, trim other treats that day.

Can kittens eat tuna?

Can cats eat tuna as kittens? PetMD says kittens should not eat human tuna. Instead, it recommends waiting until a cat is at least one year old. Until then, a complete kitten food meets all their needs.

Risks When Cats Eat Tuna Every Day

Mercury

Mercury builds up in the body over time, especially with frequent meals. According to PetMD, cats that eat large amounts of tuna can develop mercury toxicity. That is why the answer to "can cats eat tuna every day" is no for human tuna.

Vitamin E deficiency and steatitis

The Merck Veterinary Manual reports that vitamin E deficiency has occurred in cats given large amounts of canned tuna. This can lead to pansteatitis, also called yellow fat disease.

In this painful condition, body fat becomes inflamed and sore. The Merck pet owner guide notes that most known cases involved cats whose diet was partly or fully fish.

Fish allergy

Fish is a common food allergen in cats, although many cats tolerate it. In a 2016 review in BMC Veterinary Research, fish caused skin food reactions in 13 of 78 cats, or about 17%. Only beef was more common. So if your cat has itchy skin, the answer to "can cats eat tuna" may be no.

An unbalanced diet

Human tuna lacks the balance of vitamins and minerals in complete cat food. For example, Cornell notes that some cats fed canned fish made for people developed serious nerve problems.

Signs Your Cat Has Eaten Too Much Tuna

Most cats that sneak a bite of tuna will be fine. In other words, can cats eat tuna by accident without harm? Usually, yes. The concern is a fish-heavy diet over weeks or months.

The Merck pet owner guide lists these signs of yellow fat disease:

• A dull coat or dry skin early on
• Tiredness and clumsy movement
• A tender back or belly, or lumps under the skin
• Fever, which is always present, and often a poor appetite

See your vet if you notice any of these, especially after a diet heavy in fish. Merck adds that treatment means changing the diet and, usually, adding vitamin E.

Tuna Cat Food vs Human Tuna: What Cats Should Eat

Cat food made with tuna is a different product, because makers balance it for cats. PetMD explains that tuna made for cats has added ingredients that make it more balanced.

That said, the key is the label. According to AAFCO, the nutritional adequacy statement is perhaps the most important part of a pet food label.

• "Complete and balanced": This food can be your cat's daily diet.
• "For intermittent or supplemental feeding only": This is a treat or topper. AAFCO even uses canned cat tuna that lacks vitamins and minerals as its example.

What the name on the can means

So can cats eat tuna cat food every day? Yes, if the label says complete and balanced. But note that a "tuna flavor" food may hold very little tuna. Meanwhile, you can feed a complete "tuna dinner" daily if it suits your cat's life stage.

Tuna and taurine

Fresh whole tuna is rich in taurine, just like other oily fish. However, the UC Davis taurine study found far less in canned albacore and chunk light tuna. So canned tuna is not a good way to cover taurine needs. Our guide to taurine foods for cats lists better sources.

What If Your Cat Eats a Whole Can of Tuna?

Don't panic. A single large serving of plain tuna in water is rarely an emergency for a healthy adult cat. However, it may cause a short bout of vomiting or loose stool.

The details matter, though. So check the can and think about what else was in it.

• Plain tuna in water: Watch your cat for a day, and skip treats until the stomach settles.
• Brine-packed tuna: Offer fresh water, since the ASPCA warns that too much salt can cause thirst, vomiting and tremors.
• Tuna salad with onion or garlic: Call your vet, because these foods can damage red blood cells in cats.

Also call your vet if vomiting continues, or if your cat seems weak or stops eating. In short, one can is a lesson in storage, not usually a crisis.

Can Cats Eat Tuna With Health Conditions?

Some cats need extra care with any treat, including fish. Because tuna is rich and calorie-dense, it can upset a special diet.

• Cats on a prescription diet: Ask your vet first, since extra food can undo the diet's balance.
• Cats with food allergies: Fish is a common trigger, so tuna may cause itchy skin.
• Overweight cats: Count tuna as part of the 10 to 15 percent treat limit.
• Picky seniors: A small topper can tempt appetite, but ask your vet if your cat stops eating.

A sample weekly plan

Here is how tuna can fit into a normal week. First, feed a complete cat food every day. Then add one tablespoon of plain light tuna on one day only.

On the other days, use different small treats, or none at all. That way, can cats eat tuna becomes a simple yes without the risks of daily fish.

Can Cats Eat Tuna Raw, as Sushi or in Tuna Salad?

Can cats eat tuna raw? No. PetMD recommends cooking tuna thoroughly before feeding it. Raw fish also brings germs into your kitchen. The ASPCA warns that raw meat can carry bacteria such as Salmonella and E. coli.

• Sushi: Skip it. It is raw, and soy sauce adds a lot of salt.
• Tuna salad: Skip it, too. The ASPCA warns that onion and garlic can damage a cat's red blood cells.
• Tuna steak: A small piece of plain, fully cooked steak is fine as a rare treat.

What about the water in the can?

Some owners drizzle a little water from a no-salt can over food to tempt a picky cat. Keep it to a small splash. Also, never use the liquid from tuna in brine or oil.

How to Let Cats Eat Tuna Safely: 7 Simple Rules

If you decide to share, these rules keep it safe. They turn "can cats eat tuna" into a clear yes for the right cat.

1. Pick light tuna packed in water, with no salt added.
2. Then drain it well and flake it into small pieces.
3. Serve about 1 tablespoon at most, once a week.
4. Also, mix it into regular food so it stays a topper, not a meal.
5. Skip it for kittens under one year old.
6. Next, avoid albacore, oil, brine, mayo and seasoning.
7. Finally, ask your vet first if your cat has kidney, thyroid or allergy issues.

Better Alternatives for Cats Who Love to Eat Fish

Can cats eat tuna less often and still enjoy fish? Yes, because you have safer options. For example, canned salmon and sardines carry far less mercury than tuna, according to FDA data.

• Plain cooked salmon, with bones and skin removed
• Sardines packed in water, with no salt added
• A complete fish-flavored cat food
• Baked chicken thigh, which is rich in taurine

Many owners offer tuna for the omega-3 fats in fish. If that is your goal, read our omega-3 for cats guide before you rely on tuna. You can also see the Kittysum Omega-3 powder.

Myths vs facts about tuna

Related guides: Taurine for cats, Taurine foods for cats ranked and Omega-3 for cats.

Related guides: Taurine dosage for cats · Taurine foods for cats · Tuna salad for cats

If you have a young cat, read our new guide on whether kittens can have tuna before you share any.

More taurine guides: Can cats have eggs? · Taurine in fish for cats

Key Terms Explained

• Methylmercury: a form of mercury that builds up in large fish such as tuna.
• Steatitis (yellow fat disease): painful fat inflammation linked to diets high in fish and low in vitamin E.
• Thiamine (vitamin B1): a vitamin that raw fish can destroy, leading to deficiency.
• Complete and balanced: a label claim that a food meets all of a cat's nutrient needs.
• Treat rule (10% rule): the guideline that treats should make up no more than about 10% of daily calories.

This article is for general education and is not veterinary advice. These statements have not been evaluated by the Food and Drug Administration. Kittysum products are not intended to diagnose, treat, cure or prevent any disease.