Can Cats Eat Tuna? What You Should Know Before Cracking Open a Can

Our feline friends love fish! However, with so many fish in the sea, you might wonder about a particularly popular favorite—tuna. That brings us to the question: can cats eat tuna?

If you've cracked open a can of tuna, you've likely heard little paws pitter-patter your way immediately after. It's an aroma—and taste!—most cats can't resist. But as your furry friend nudges your hand, pleading for the delicious fish, should you share?

While tuna is not toxic to cats, making it safe to eat, it's not recommended as a staple in your cat's daily diet.

cat with background pattern of tuna; can cats eat tuna?
cat with background pattern of tuna; can cats eat tuna?

Luxx Images / bigacis / Getty

Is Tuna Good or Bad for Cats?

Tuna is a low-calorie, high-protein food packed with nutrients like vitamin B12, omega-3 fatty acids, and vitamin D. These are known to promote healthy blood and nerve cells, cardiovascular health, and strong bones and muscles, respectively.

But is this savory saltwater fish just as nutritious for cats as it is for us? Or is tuna bad for cats?

Tuna undoubtedly has its nutritional benefits. But if fed too often, it can lead to potential health problems in cats.

According to the Merck Veterinary Manual, fish is among the top foods cats are most often allergic to. (In fact, it's the first food mentioned!)

Signs of food allergies in cats include:

  • Small, crusty bumps

  • Hair loss

  • Redness

  • Itching

  • Vomiting

If your cat starts displaying these signs after introducing tuna (or any other kind of fish) to her diet, it's quite possible she's allergic.

RELATED: Can I Give My Itchy Cat Benadryl?

Another concern is mercury poisoning. Mercury is a toxic metal found in the water, air, and soil. All fish contain mercury, but tuna has higher levels compared to other types of fish. Both cats and humans can get mercury poisoning if they eat too much tuna over a long period of time.

Signs of mercury poisoning in cats include:

  • Loss of coordination

  • Unsteady gait

  • Abnormal behavior

  • Tremors or seizures

  • Involuntary body and eye movements

  • Central nervous system depression

  • Vision loss

  • Death

Note: Before you start throwing out your cans of tuna, it's important to mention that mercury poisoning cases have—fortunately—declined in recent years. (Whew!)

Lastly, too much tuna can lead to weight gain in your cat. Tuna is a relatively healthy food for us humans, but those calories hold much more weight for our four-legged friends—literally. And though chonky kitties are absolutely adorable, excess weight can result in chronic inflammation, heart disease, diabetes, and cancer.

By following the 10 percent rule with snacks and treats for our cats, we can help keep our beloved felines at a healthy weight so they can live a longer life.

Can Cats Eat Tuna Sometimes?

On one hand (or paw), tuna can pose health risks if fed too much and too often, while on the other, cats can technically eat it since it's not toxic. So, you might be wondering if you can—and should—feed your cat their favorite fish at all.

The good news?

"Tuna can be fed to cats but in moderation. It is best used to flavor food or for a cat who is temporarily off her food," says Debra Eldredge, DVM at Senior Tail Waggers and award-winning author of Cat Owner's Home Veterinary Handbook.

If your cat just can't get enough of tasty tuna, look out for the different types of tuna since they can contain various levels of nutrients—and mercury—depending on the kind you get, Eldredge explains.

"Straight tuna is high in unsaturated fats and does not have antioxidants, such as vitamin E, to balance that. It is also not balanced," she says. "Tuna, especially the albacore variety, can be high in mercury. (This is why tuna is not recommended as a daily meal for people either.) Because it is a protein food, there is always potential for allergic reactions as well."

Similar to other fish, like salmon, it's recommended to cook tuna before serving it to your kitty-cat to ensure a safe feed. Bon appétit!

How Much Tuna Can I Feed My Cat?

Our cats would eat tuna all day, every day if they could. But we know that as much as they fancy it, it's in their best interest that they don't eat too much tuna. As the saying goes, "Everything in moderation."

"Putting some juice from tuna canned in water into your cat's water bowl occasionally may encourage drinking—always a good thing. Tuna flavored cat foods (make sure the label says balanced and complete) are popular with many cats," Eldredge says. "The bottom line: don't look at tuna as a meal for your cat. Instead, it can be a rare treat or a flavoring/ingredient in a balanced food."

RELATED: How Much Should I Really Feed My Cat?