Dogster is reader-supported. When you buy via links on our site, we may earn a commission at no cost to you. Learn more.

Dog Nutrition

Can Dogs Eat Tuna? Vet-Verified Health & Nutrition Facts

Kit Copson
By Kit Copson · Reviewed & fact-checked by Dr. Ashley DarbyVet Approved
Dr. Ashley Darby
Reviewed & Fact-Checked byDr. Ashley DarbyBVSc (Veterinarian)
Dr. Ashley has worked in mixed and small animal emergency clinics and general practice ever since 2017 after studying Sydney University. She grew up in South Africa and England before moving to Australia, and her passion for animals came from many childhood safaris in the Kruger National Park.View authorThe information is current and up-to-date in accordance with the latest veterinarian research. Learn more
Updated on June 29, 2026
Share
Can Dogs Eat Tuna

Many dogs love fish, and its strong, distinctive scent never fails to get their mouths watering. But does that mean dogs can safely eat tuna? Tuna is not toxic to dogs. Adult dogs can eat plain, water-packed, light canned tuna in moderation. However, you need to be mindful of the amount of mercury your dog is consuming when they eat tuna.

Certain kinds of fish—including albacore tuna—have higher mercury content and are not a good option for dogs, although they are not inherently toxic, so a one-off meal is unlikely to hurt them. Read on to find out more.

Dogster divider_v2_NEW_MAY_24_

Why Can't Dogs Eat a Lot of Tuna?

Tuna is a large fish that's harvested quite late in life, and this means over time, there is a build-up of the heavy metal called mercury in the fish's tissues. Fish meat in general has higher concentrations of mercury compared to chicken or beef, therefore even commercial fish based dog food has higher mercury concentrations than diets based on other proteins. However, it has been concluded that commercial fish-based diets are unlikely to cause any mercury poisoning in dogs 1.

Mercury poisoning due to chronic exposure is unlikely in domestic animals. Most cases of mercury poisoning are due to exposure to inorganic mercury sources. That being said, it’s a good idea to be on the safe side with dogs and assume they are more sensitive to mercury in food than we are. In addition, fetuses and young animals may be more sensitive to the effects of mercury, so dietary mercury is best avoided in pregnant female dogs and puppies.

While mercury poisoning is uncommon, it can be severe so we recommend exercising caution, and not feeding tuna as the only source of protein in your dog’s diet. Your dog won’t be missing out if you don’t offer tuna regularly, and if only fish must be fed due to a food allergy, there are options with lower mercury levels which should be used.

Be mindful of the human recommendations for tuna consumption, and remember to take the weight of your dog into consideration; smaller dogs will have a lower tolerance for mercury in the diet.

Image Credit: Jaromir Chalabala, Shutterstock
Dogster divider_v2_NEW_MAY_24_

Benefits & Dangers of Feeding Tuna to Dogs

Tuna is low in fat and a source of various nutrients, including protein, omega-3 fatty acids, niacin, selenium, vitamin B12, and vitamin D, so your dog may receive some benefits from small amounts on occasion. For example, omega-3 fatty acids are good for keeping the coat healthy and shiny. However, there are some risks involved in feeding too much tuna to a dog. Let's explore this further.

Mercury Poisoning

A case of mercury poisoning was documented in the 90s; the source of toxicity was not identified in this case, but chronic consumption of fish was suggested as a plausible cause. The early signs of mercury poisoning are subtle and include brain and nervous system depression.

Later signs of mercury poisoning include diarrhea, vomiting, lethargy, appetite loss, struggling to walk, incoordination, convulsions, and tremors.

In some cases, mercury poisoning can cause dogs to go blind or suffer from kidney failure. Paralysis and anorexia are also a possibility for dogs with serious mercury poisoning, and it can be fatal. Please contact a vet right away if you suspect mercury poisoning.

Stomach Upset

If your dog eats tuna packed in oil, this could lead to gastrointestinal upset because the oil is too harsh on the system. Your dog may vomit or experience diarrhea. In serious cases, pancreatitis may be triggered by the consumption of too much oil, so be careful about the kind of tuna your dog eats.

Small amounts of water-packed tuna should be the only kind offered and—again—in moderation only. If your dog has managed to eat a lot of tuna—especially oil-packed tuna—be on the lookout for after-effects and contact your vet if you spot anything strange.

Parasites

Raw tuna and other kinds of fish and meat can carry pathogens that could cause diseases. Salmonella and Listeria are two of the possible infection types dogs and humans may get from raw fish. On that basis, the American Veterinary Medical Association does not recommend feeding raw animal products to dogs or cats.

Image Credit: Przemek Iciak, Shutterstock

Seasoning Toxicity

If you do feed tuna on occasion, make sure it's only plain, water-packed canned tuna and that there are no added oils. These can cause pancreatitis in dogs. Additionally, some seasonings, such as onions and garlic, are toxic to dogs. Other additives may be simply irritating to their gastrointestinal system and cause digestive upset.

Dogster divider_v2_NEW_MAY_24_

Which Fish Have the Highest Mercury?

You can check the mercury content of certain seafoods on the US Food and Drug Administration (FDA) website. In addition to albacore tuna, a few other kinds of fish can contain very high mercury levels so are not recommended for dogs.

These include:

  • Albacore tuna
  • Bigeye tuna
  • Yellowfin tuna
  • Tilefish
  • Shark
  • Swordfish
  • King mackerel
Dogster divider_v2_NEW_MAY_24_

What Kinds of Fish Are Safe for Dogs?

If your dog is a fish fan, they're in luck because there are plenty of safe types they can eat as a treat. These are harvested much earlier than unsafe types of fish, so their mercury levels aren't as high, and several can be found in dog food formulas. Remember to feed these plain, cooked, and without seasonings, and feed in moderation only.

As a reminder, your dog's complete and balanced food formula should be the bulk of their diet, and treats should make up no more than 10% of the daily calorie intake. Even the safe fish listed below should be treated as occasional snacks rather than a regular part of the diet unless they're part of a complete and balanced food formula that you feed every day.

  • Salmon
  • Herring
  • Whiting
  • Cod
  • Whitefish
  • Catfish
  • Sardines packed in water (not oil)
Dogster divider_v2_NEW_MAY_24_

Conclusion

Tuna is a tricky business because while a little bit now and then isn't considered harmful to dogs, going overboard can make them sick, so be sure to be mindful of how much tuna you are offering your dog and stick to fish with a lower mercury content. Ideally, your dog’s main protein source is from dog food, and some light canned tuna in water is given as a treat occasionally. They don’t need to have tuna every day as there are plenty of accessible, safer fish options. Talk to your veterinarian if you want to provide a healthy, balanced fish diet to your dog for health reasons.

See also: 

Sources

Featured Image Credit: DronG, Shutterstock

Want content like this delivered to you?

Sign Up For Our Newsletter

News, insights, expert advice, and everything dog

* By submitting, you agree to our Terms & Conditions and Privacy & Cookies Policy.

Kit Copson
Authored by

Kit Copson

Can Dogs Eat Fish? Vet-Verified Facts & FAQ

Can Dogs Eat Fish? Vet-Verified Facts & FAQ

Though fish is most commonly associated with cats, many dogs love it, too. If your dog goes bonkers for a fishy treat, they’re in luck—in most cases, dogs can…

Kit Copson
By Kit Copson · 1 week ago
Can Dogs Eat Swordfish? Vet-Approved Facts & FAQ

Can Dogs Eat Swordfish? Vet-Approved Facts & FAQ

Many owners choose to feed their canine companions a kibble-based diet, which has been proven to be a reliable source of all the necessary nutrients that dogs…

Jana Blagojevic
By Jana Blagojevic · 1 week ago
Can Dogs Eat Sardines? Vet-Verified Nutrition, Types & Preparation

Can Dogs Eat Sardines? Vet-Verified Nutrition, Types & Preparation

Sardines or pilchards are a type of oily fish used for bait purposes or served as food. They are noticeably rich in healthy fats, vitamins, minerals, and prote…

Sarah Psaradelis
By Sarah Psaradelis · 1 week ago
Can Dogs Eat Mackerel? Vet-Verified Nutrition Facts

Can Dogs Eat Mackerel? Vet-Verified Nutrition Facts

Mackerel is a term that applies to various species of swift-moving fish that are mainly part of the Scombridae family. These oily fish are rich in nutrients, p…

Rachel Giordano
By Rachel Giordano · 1 week ago
June 29, 2026

Can Dogs Eat Cod? Vet-Approved Facts & FAQ

Ocean fish like cod can provide many health benefits for humans and our dogs. Cod is a protein-rich fish that is great for dogs, and they can eat it without an…

Beth Crane
By Beth Crane
Can Dogs Eat Cod? Vet-Approved Facts & FAQ
June 29, 2026

Can Dogs Eat Seafood? Vet-Reviewed Health Facts, Benefits & Risks

Seafood is a delicacy and is loved by many people, but what about humans’ best friends? Can dogs also indulge in the delights of the ocean? The short answer is…

Genevieve Dugal
By Genevieve Dugal
Can Dogs Eat Seafood? Vet-Reviewed Health Facts, Benefits & Risks
June 29, 2026

Can Dogs Eat Squid? Vet-Verified Health Benefits & FAQ

Dogs can eat squid in small amounts occasionally. The squid must be cooked to ensure that there aren’t any food-borne illnesses in the squid. Seasonings should…

Kristin Hitchcock
By Kristin Hitchcock
Can Dogs Eat Squid? Vet-Verified Health Benefits & FAQ
June 17, 2026

Can Dogs Have Tilapia? Vet-Verified Nutrition Facts & FAQ

Tilapia is one of the most commonly eaten fish around, so if you’re a fan of fish, chances are you eat this fairly often. As such, you may be tempted to feed y…

Misty Layne
By Misty Layne
Can Dogs Have Tilapia? Vet-Verified Nutrition Facts & FAQ
June 27, 2026

Can Dogs Eat Salmon? Vet Reviewed Nutrition Facts & Precautions

When you think of dog food, you probably think of beef or chicken instead of novel protein sources like salmon. Part of the reason lies in the habitat we assoc…

Kerry-Ann Kerr
By Kerry-Ann Kerr
Can Dogs Eat Salmon? Vet Reviewed Nutrition Facts & Precautions
June 29, 2026

Can Dogs Eat Mahi Mahi? Vet-Reviewed Facts

Providing your dog with the best possible diet is a top priority for all dog owners, but sometimes we may feel like our dogs get bored with the same meals ever…

Nicole Cosgrove
By Nicole Cosgrove
Can Dogs Eat Mahi Mahi? Vet-Reviewed Facts
July 4, 2026

Can Dogs Eat Trout? Vet Reviewed Facts & Info

Are you considering giving your dog some tasty trout? You may be wondering if this popular fish is safe for them to digest. So, can dogs eat trout? To cut a lo…

Hanh Duong
By Hanh Duong
Can Dogs Eat Trout? Vet Reviewed Facts & Info
June 29, 2026

Can Dogs Eat Raw Salmon? Vet-Verified Nutrition Facts & Advice

Salmon is packed full of healthy nutrients and is considered by some to be one of the healthiest protein sources since it provides essential vitamins and is a…

Lorre Luther
By Lorre Luther
Can Dogs Eat Raw Salmon? Vet-Verified Nutrition Facts & Advice

Love Dogs? So Do We! Join the Dogster Community

Stay informed with expert pet care insights delivered straight to your inbox! Discover professional guidance on animal behavior, feeding tips, trusted product picks, and much more.

You may opt-out at any time. View our Privacy Policy for more information.

The Dogster app on a phone