Can Dogs Eat Tuna?

By the Animal Wellness Desk · Facts last checked October 21, 2026 · General information, not a vet visit

Tuna is a common pantry staple, so dog owners often wonder if it is safe to share. The answer is that dogs can eat tuna, but only in small amounts as an occasional treat. A little bit of cooked or canned tuna is generally safe for most healthy dogs, but it should not become a regular part of their diet.

While many dogs enjoy the taste, tuna comes with certain risks that make it unsuitable for frequent feeding. It is best reserved as an infrequent addition to a balanced meal, not as a meal on its own.

Tuna and dogs: the facts in one table

Why tuna can be tricky for dogs

The primary concern with tuna is its mercury content. As a large, long-living fish, tuna can accumulate mercury from its environment. This heavy metal can build up in a dog’s system over time if tuna is fed regularly, which is the main reason it should only be an occasional food item.

Another issue is sodium. Some canned tuna products contain added salt, which is not healthy for dogs in large amounts. To avoid excess salt, always choose tuna packed in water instead of brine and check that the label shows no salt has been added. It is always wise to read the ingredient label on any food you share with your pet.

How to offer tuna safely and what to avoid

If you choose to give your dog tuna, preparation is key. Always supervise your dog when introducing any new food. Follow these guidelines for safer sharing:

• Choose the right kind. Offer only plain, cooked fresh tuna. If using canned tuna, select one packed in water, not oil, with no added salt or other seasonings. Even with the correct type, the portion should be small.
• Keep it simple. Never give your dog tuna salad. These preparations often contain ingredients like mayonnaise, onions, or other spices that can be harmful to dogs.
• Introduce it slowly. As with any new food, start with a very small piece to see how your dog’s digestive system reacts before offering a few more bites.

Remember that treats should only make up a small part of your dog’s overall balanced diet.

When it’s better to skip tuna

Tuna is not a suitable treat for every dog. It is best to avoid giving it to dogs with specific health conditions or dietary sensitivities. If your dog has a sensitive stomach, it is wise to stick to their regular food to prevent potential upset.

Because the risks associated with mercury are related to accumulation over time, do not make tuna a frequent offering. If you are looking for a fish to share more regularly as a small treat, you can ask your veterinarian about other options that are lower on the food chain and contain less mercury.

When to call your vet

Most dogs who eat a little plain tuna need nothing more than watching. Call your vet if anything below shows up, or if your dog has a health condition or is on a special diet.

If your dog eats a large amount of tuna, especially if it was prepared with oil, salt, or other seasonings, watch for signs of digestive upset like vomiting, diarrhea, or a sore belly. Contact your veterinarian or the ASPCA Animal Poison Control Center if you have concerns. Be prepared to tell them what your dog ate, how much, and when it happened. If possible, keep the packaging for reference.

Emergency signs: go now

• Collapse, fainting or severe weakness
• Seizures, tremors or trouble standing
• Trouble breathing or blue, gray or very pale gums
• Repeated vomiting or retching, or a swollen, painful belly
• Any known contact with a substance listed as toxic, even before signs appear

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• Vomiting or diarrhea that lasts or keeps coming back
• Not eating or drinking, or drinking much more than usual
• Drooling, pawing at the mouth or a swollen face
• Lethargy, hiding or acting unlike themselves

ASPCA Animal Poison Control Center: (888) 426-4435 (a consultation fee may apply). Your own vet or nearest emergency clinic is always a good first call.

Sources

• American Kennel Club: Can Dogs Eat Tuna?
• American Kennel Club: People Foods Dogs Can and Can’t Eat

Last checked October 21, 2026. Listings and guidance can change; your veterinarian knows your pet’s health history.