Can Cats Eat Tuna? A Science‑Based Guide

Imagine this: I crack open a can of tuna in the kitchen, and within seconds, my cat Luna is weaving between my legs, meowing with anticipation.

Our feline friends love the smell and taste of tuna – it’s like kitty catnip from the sea. Can cats eat tuna safely?

In this article, we share our first-hand experience and veterinary-backed knowledge to answer that question. We’ll explore tuna’s nutritional perks in small doses, the potential risks of overindulgence, which types of tuna are safest, and how to serve it properly.

We’ll also provide a handy feeding chart, special cautions for kittens, and a quick do’s-and-don’ts summary.

Our goal is to give you practical, science-based guidance so you can treat your cat while keeping them healthy. Let’s dive in!

Nutritional Benefits of Tuna (In Small Quantities)

When offered occasionally and in moderation, tuna does have some benefits for cats. Here are a few positives of tuna as a treat:

High-Quality Protein

Cats are obligate carnivores, meaning they require a meat-based diet. Tuna is packed with protein, which supports your cat’s strong muscles and energy needs. A small tuna snack can complement your kitty’s protein intake.

Rich in Omega-3 Fatty Acids

Tuna (especially fatty tuna cuts) contains omega-3 fatty acids like EPA and DHA. These healthy fats can help maintain a shiny coat and healthy skin, and they have anti-inflammatory benefits for the heart, joints, and kidneys.

In cats with certain inflammatory conditions, a little omega-3 boost from tuna might be beneficial.

Low in Carbohydrates

Unlike many commercial treats, plain tuna has virtually no carbs. This is a plus because cats aren’t built to process a lot of carbohydrates. In fact, too many carbs can predispose cats to weight gain and even diabetes.

Tuna’s carb-free nature means an occasional bite won’t upset a carnivore’s diet plan.

Enticing Aroma and Flavor

Practically speaking, tuna’s strong scent can be very motivating for a finicky cat. We’ve used a dab of tuna to entice a sick cat to eat or even to hide medication. The “tuna magic” often gets cats interested in food when nothing else does.

Just be careful – your cat might start demanding tuna at every opportunity!

While these benefits sound great, remember that they apply only to small, infrequent servings of tuna. Tuna is not a complete food for cats – it’s missing some key nutrients (more on that next). Think of tuna as a yummy bonus to reward your cat now and then, not as a daily staple.

Risks of Feeding Tuna to Cats

Even though cats go crazy for tuna, there are serious reasons to limit how much and how often they get this fish. Let’s break down the major risks when it comes to cats eating tuna:

Mercury Toxicity

Tuna, especially large ocean tuna like albacore, accumulates mercury – a heavy metal that’s toxic to nerves. Too much mercury can damage a cat’s nervous system, leading to neurological signs (like loss of coordination, balance problems, or tremors) that may be irreversible. 

Cats are small compared to humans, so even a little mercury can have a big impact. Signs of mercury poisoning in cats (wobbly gait, dilated pupils, tremors) might not show up until significant damage is done. 

This is why experts warn to strictly limit tuna treats and avoid high-mercury tuna varieties for cats.

Nutritional Imbalances

Tuna is not nutritionally complete for cats. Dr. Christine Klippen, DVM explains that while tuna has protein and some fats, it lacks many essential vitamins and minerals cats need.

Notably, tuna is deficient in vitamin E and also low in taurine, B vitamins, and other nutrients that must be in a cat’s diet.

Addiction & Food Refusal

It’s no secret that cats become obsessed with tuna. Many a pet parent has made the mistake of spoiling their kitty with frequent tuna snacks, only to find the cat starts turning up its nose at regular food.

Tuna’s tastiness can create a “tuna junkie” – a cat that holds out for tuna and refuses balanced cat food.

This is dangerous because your cat might end up eating an unbalanced diet or not eating enough overall. We recommend never letting tuna become a daily expectation; keep it a surprise treat so your cat doesn’t develop a fishy fixation.

Overfeeding & Obesity

Tuna may seem light, but those flaky morsels carry more calories than you’d think. A few ounces of canned tuna (about half a can) can approach ~100 calories – which is over a third of the daily calories an average indoor cat needs!

It’s easy for well-meaning owners to accidentally overfeed tuna as treats, causing weight gain.

Always count tuna as part of your cat’s total calorie intake for the day. Moderation is key to prevent your treat from turning into a health burden.

Bacterial or Parasite Risk (if Raw)

Serving tuna raw (or any raw fish) to cats is not recommended. Raw fish can carry bacteria like Salmonella or Listeria, which can make your cat (or you) very sick.

Additionally, raw tuna contains an enzyme called thiaminase that destroys vitamin B1 (thiamine).

In large amounts raw tuna could actually cause a thiamine deficiency, leading to neurological problems and heart issues in cats. Cooking the tuna denatures (eliminates) thiaminase, so always feed tuna cooked.

Which Types of Tuna Are Safer for Cats?

Not all tuna is created equal. The way tuna is prepared (and what kind of tuna it is) makes a big difference in how safe it is for your cat. Here’s how to pick the safest options:

Fresh Tuna – Only If Cooked and Plain

f you have a fresh tuna steak (or sashimi-grade tuna), do not give it to your cat raw. Instead, cook it thoroughly (bake, boil, or pan-cook with no oil) until it’s well done.

Cooking kills harmful bacteria/parasites and destroys thiaminase enzyme. Never add salt, marinades, or seasonings – the tuna should be served totally plain.

Once cooked and cooled, offer a small piece. Fresh, cooked tuna (in moderation) is generally safe as a treat.

Canned Tuna – Choose Water-Packed, No Salt

Canned tuna can be a convenient cat treat, but you must read labels. Opt for tuna packed in water, not oil. Tuna in oil adds unnecessary fat and can upset your cat’s stomach. Also look for “no salt added” or low-sodium versions if possible.

Regular canned tuna often contains added salt for flavor, which cats don’t need. Before serving, you can rinse canned tuna in fresh water to remove excess sodium. Again, no flavors or seasonings – just simple tuna in water is acceptable.

Many veterinarians specifically warn against tuna in brine or oil for cats because of the additives.

 “Light” Tuna vs. “White” Tuna (Mercury Levels) 

The species of tuna matters due to mercury content. Smaller tuna species, often sold as “chunk light” tuna (e.g. skipjack tuna), tend to have lower mercury levels. In contrast, “white” tuna (albacore) and larger tuna like yellowfin or ahi accumulate much more mercury in their flesh.

Tuna-Based Cat Products

An alternative to giving “people tuna” is to use tuna-flavored cat foods or treats. Many pet food companies offer formulated tuna treats or wet foods that smell and taste like tuna but are balanced with vitamins and minerals for cats.

For instance, tuna-flavored lickable treats or pouch toppers can satisfy your cat’s craving without the nutritional gaps of plain tuna. These products use tuna as an ingredient but supplement taurine, vitamin E, etc., making them safer for frequent use.

Just be sure any commercial treat you choose is from a reputable brand and is intended for cats (and still feed them sparingly). Using these can let your cat enjoy the tuna taste guilt-free, since they’re designed to meet feline dietary needs.

How Often Can Cats Eat Tuna? (Feeding Frequency & Safe Serving Size)

With tuna, frequency and portion size are everything. The golden rule we follow is: tuna as an occasional treat, not a regular meal. Both veterinarians and nutrition experts agree that tuna should be at most a small percentage of a cat’s diet.

One guideline is the “10% rule” – treats (including tuna) should make up no more than 10% of your cat’s overall calories. The rest should come from a complete, balanced cat food.

So what does 10% look like in practical terms? Dr. Klippen (a vet nutritionist) helped create the chart below to illustrate approximate maximum tuna amounts for cats of various sizes. This chart assumes tuna is the only treat and the cat is otherwise eating a normal amount of regular food.

Safe Tuna Treat Guidelines (Approx. 10% of Diet by Cat’s Weight):

Finally, always monitor your cat after giving tuna. Watch for any stomach upset (vomiting or diarrhea) that might indicate it didn’t agree with them. Also observe their appetite at the next meal – if they start holding out for tuna and snubbing their kibble, scale back the tuna treats.

Consistency is key: your cat should see tuna as a rare bonus, not an expected part of dinner.

Can Kittens Eat Tuna?

If adult cats should have tuna only occasionally, what about kittens? Generally, it’s best not to give tuna to kittens at all. Kittens (under one year old) have developing bodies and very specific nutritional requirements for growth.

A kitten’s diet should be 100% complete and balanced for kittens – usually a quality kitten food – with no room for “empty” treats like tuna.

There are a few reasons to be extra cautious with kittens:

Nutrient Needs

Kittens need higher levels of protein, calcium, and certain vitamins/minerals than adult cats to support their rapid growth. Tuna on its own doesn’t supply the right balance for a growing kitten.

For example, kittens require plenty of calcium for bone development, and tuna meat has very little calcium. Over-reliance on tuna could seriously unbalance a kitten’s diet.

Sensitive to Deficiencies

Because kittens are growing, even a short-term deficiency in an essential nutrient can harm their development. An adult cat might tolerate the lack of vitamin E in tuna for a while, but a kitten could develop problems more quickly.

Kittens are also more at risk for thiamine deficiency if fed raw fish (which, again, you should never do) and for fatty acid or taurine deficiencies on an unbalanced diet.

Higher Vulnerability to Toxins

A kitten’s body weight is small, so toxins like mercury have an even more pronounced effect. The mercury in tuna that might be a minor concern for a 10 lb adult cat can be a big deal for a 2 lb kitten.

Young animals also may not detoxify or excrete substances as efficiently. According to veterinary guidance, kittens are especially sensitive to dietary toxins and imbalances, so it’s safest to avoid tuna until they’re older.

Summary: Tuna Treat Do’s and Don’ts for Cat Owners

We’ve covered a lot of info, so here’s a quick rundown of the most important do’s and don’ts when it comes to feeding your cat tuna:

Do:

· Offer Tuna as an Occasional Treat, not a meal replacement. Keep it infrequent (for example, a small bite once a week or a few times a month). Cats should get most of their nutrition from balanced cat food, with tuna only as a special reward.

· Use Plain, Cooked Tuna with no added salt or seasoning. If using canned tuna, choose water-packed, low-sodium light tuna (skipjack). If cooking fresh tuna, cook it thoroughly and let it cool, with no oils or spices.

· Keep Portions Very Small. A teaspoon or two of tuna is plenty for one serving. Remember, treats (including tuna) should be <10% of daily calories. When in doubt, err on the side of less.

· Monitor Your Cat’s Reaction. After giving tuna, watch for any digestive upset or allergic signs. Also ensure they continue to eat their regular food normally. If you notice any issues (vomiting, itchiness, refusal of normal food), cut out the tuna and consult your vet.

· Consider Tuna-Flavored Cat Treats as a safer alternative. It’s fine to indulge your cat’s fishy cravings with commercially made cat treats or foods that include tuna in a balanced formula. These can satisfy your cat while providing the taurine, vitamins, and other nutrients that plain tuna lacks.

Don’t:

· Don’t Feed Tuna Daily or in Large Quantities. Frequent tuna feeding can lead to mercury buildup, nutrient deficiencies, and picky eating habits. Avoid letting tuna become a significant part of your cat’s diet – no matter how much they beg.

· Don’t Give Raw Tuna or Fish. Raw fish poses a risk of parasites and contains thiaminase, which can cause vitamin B1 deficiency in cats. Always cook tuna before offering it to your pet.

· Don’t Serve Tuna with Oil, Brine, or Seasonings. Oil-packed tuna and salty brine are not healthy for cats. And any tuna seasoned with ingredients like onion, garlic, or spices is unsafe (onion and garlic are toxic to cats). Stick strictly to plain fish.

· Don’t Replace Balanced Cat Food with Tuna. It might be tempting if you run out of cat food to open a can of tuna instead, but this is not a good long-term plan. Even short-term, a diet of only tuna can cause malnutrition. Use tuna sparingly and get your cat back on a complete diet ASAP.

· Don’t Give Tuna to Kittens (<1 year). Kittens have special dietary needs and sensitivities, so they should not eat tuna treats. Wait until they’re older to introduce any “human” foods. In the meantime, focus on quality kitten food to ensure proper growth.

Conclusion

In the end, the answer to “Can cats eat tuna?” is yes – but only in moderation and with precautions. Our SnuggleSouls team lives by the mantra “tuna is an occasional treat, not a staple.” 

A bite of tuna can make your cat’s day, providing extra protein and tasty excitement, but too much tuna or the wrong kind can spell trouble.

Always prioritize a complete and balanced diet for your cat’s everyday meals, and view tuna as a special indulgence. Serve it plain, in tiny portions, and infrequently.

Your cat’s health and happiness are worth the effort – a little restraint with treats now will help ensure they thrive for years to come.

Want to learn more about your cat’s diet?

FAQ

Can cats eat canned tuna?

Yes, but only in moderation and under specific conditions. Choose water-packed, low-sodium tuna without any seasonings or additives. Avoid oil-packed or flavored varieties.

Is tuna safe for kittens?

No. Kittens have sensitive systems and higher nutritional needs. Tuna can cause imbalances, mercury exposure, or allergic reactions. Wait until the kitten is at least one year old.

How much tuna can I give my cat?

As a rule, tuna should not exceed 10% of your cat’s daily caloric intake. For a 10 lb cat, that’s around 0.7 oz (≈20 grams) a day — and even then, not every day.

What are the signs of mercury poisoning in cats?

Symptoms may include poor coordination, tremors, dilated pupils, head tilting, or seizures. If you suspect mercury poisoning, seek veterinary care immediately.

Can cats become addicted to tuna?

Yes. Some cats may start refusing their regular food in favor of tuna. This can lead to nutrient deficiencies and picky eating behavior.

Is raw tuna okay for cats?

No. Raw tuna contains thiaminase, which can destroy vitamin B1 (thiamine), and may also carry harmful bacteria or parasites.

What are safer alternatives to plain tuna?

Tuna-flavored cat treats or wet foods formulated for feline nutrition are safer alternatives, as they contain balanced nutrients and are designed for cats.

References

Blakley, B. R. (2024). Mercury poisoning. Merck Veterinary Manual. Retrieved June 9, 2025, from https://www.merckvetmanual.com/special-pet-topics/poisoning/mercury-poisoning

Harari, J. (2020). Yellow fat disease in cats and other animals (Nutritional steatitis). Merck Veterinary Manual. Retrieved June 9, 2025, from https://www.merckvetmanual.com/musculoskeletal-system/myopathies-in-small-animals/yellow-fat-disease-in-cats-and-other-animals

Klippen, C. A. (2022). Should you feed tuna to your cat? Veterinary considerations. Tufts Clinical Nutrition Service. Retrieved from https://vetnutrition.tufts.edu/2022/08/tuna-and-cats

Mitchell, S. C., DVM. (2024, April 1). Can Cats Eat Tuna? PetMD. Retrieved from https://www.petmd.com/cat/nutrition/can-cats-eat-tuna

WSAVA Global Nutrition Committee. (2021). Nutrition guidelines for healthy cats and dogs. Retrieved from https://wsava.org/global-guidelines/global-nutrition-guidelines/

Boyers, L. (2025, April 30). Can Cats Eat Tuna? Chewy. Retrieved from https://www.chewy.com/education/cat/food-and-nutrition/can-cats-eat-tuna

ASPCA. (n.d.). People Foods to Avoid Feeding Your Pets. Retrieved June 9, 2025.