Can Dogs Eat Tuna? (We Find Out)

  • By: Andrew
  • Time to read: 16 min.

As a responsible dog owner, you’ll know that certain foods are simply off-limits, such as chocolate and onions, which are big no-nos for dogs. However, you also know that your dog is at its healthiest when it gets a well-balanced diet full of healthy proteins and fats. If you’re looking to branch out from kibble, you might be wondering if you can include tuna in your pup’s new diet.

Dogs can eat tuna, however, only certain types, and in moderation. Tuna is high in fatty acids, and too much can have adverse effects. Only give tuna to adult dogs and do so slowly, monitoring your dog for signs of any allergic reactions. Adding tuna will improve your dog’s coat and general health.

In this article, we will discuss the health benefits of tuna to your dog along with the different kinds you can feed them. We’ll also look into how and when to feed your dog tuna and when it may not be the best idea. Lastly, we’ll look into mercury poisoning and how to look for signs your dog may have become ill.

What You Should Know About Tuna

Tuna is a type of fish found in the ocean and is a lovely treat for humans and pets alike. However, there are nearly twenty species of tuna, the majority of which are not safe for your dog to consume. Of the twenty species, only seven are safe for dogs, so it’s vital you check the source before feeding. These include:

  • Skipjack
  • Albacore
  • Yellowfin
  • Bluefin
  • Bigeye

You may have heard in the past that tuna is unsafe for your dog due to the mercury levels sometimes found in the flesh. However, this has been debunked, and though tuna has minor concentrations of mercury, it is too insignificant to cause any real alarm. In general, only giant tuna carry high enough mercury concentrations for you to be concerned about, and given the price of such fish, it is unlikely you’ll be feeding this to your dog.

Should You Feed Your Dog Tuna?

There are a number of health benefits your dog will get from eating tuna. It is full of vitamins, protein, and Omega-3 fatty acids, which help to keep their coats shiny and healthy. However, as with anything high in fat, it is important to note that the quantities should be kept low, and it is not recommended to feed your dog tuna on a daily basis.

Tuna Is High in Protein

Like human beings, your pup deserves a well-balanced diet for a healthy and fruitful life. What you feed your dog is directly proportional to the quality of its health, which is why you may be looking into adding tuna in the first place.

Protein is essential to dogs, and they need a variety of different kinds, such as red meat, fish, and vegetables. Being low in calories and fat, tuna is a fantastic source of close-to pure protein for your dog. This protein builds and repairs healthy muscles, and your dog will, in turn, be more active and less likely to suffer from obesity.

Tuna Is High in Vitamins and Minerals

Just like us, your dog’s body needs essential vitamins for maintenance and growth. To ensure they’re getting everything they need, it’s crucial to avoid kibble that is cheap and full of fillers, such as animal by-products and corn.

Tuna will provide your dog with essential minerals, including:

  • Magnesium
  • Phosphorous
  • Choline
  • Iodine Selenium
  • Potassium.

Your dog will also get plenty of the complex vitamins B and D for enhanced immunity. These vitamins and minerals also facilitate a healthy nervous system for your dog, so, hopefully, you won’t need to visit your vet so often.

Omega-3 Gives Your Dog a Healthier Coat

Tuna is rich in Omega-3, a fatty acid that is great for maintaining healthy skin free from itching and inflammations. With healthy skin comes healthy fur, and you’ll likely see your dog’s coat become fuller and shinier when you include tuna in their diet.

Omega-3 also promotes a healthier heart and better eyesight for your dog.

Why You May Not Want To Feed Your Dog Tuna

As with anything, there are pros and cons to what you feed your dog. Other than the (very) small chance of mercury poisoning, you should also know that tuna is not cheap, and it may become quite expensive to try and include it in your dog’s diet.

Always remember to consult with your vet before giving your dog new foods, and do so slowly so you can see how they react. The last thing you need is to find your dog has an allergy after you’ve already fed them a big portion.

You Are on a Budget

While the benefits of feeding your dog tuna are extensive, doing so may become an issue when you see your weekly grocery bill. Unlike other fish products, tuna is relatively expensive and is a highly sought-after delicacy.

Instead, maybe look for kibble or wet food that includes tuna (or any kind of fish). Alternatively, try dried fish as treats if you’re specifically seeking those Omega-3s.

You Fear Poisoning Your Dog

As mentioned earlier, the chances of your dog becoming ill from mercury is very low. However, tuna do absorb mercury from the ocean, so it is not completely off the table. This is why we recommend feeding your dog tuna only in moderation and never every day.

Keep in mind that larger varieties of tuna are known to have a considerable amount of mercury due to their long life in the oceans. However, smaller tuna don’t have such quantities, making them safer for your dog.

In general, small portions of tuna will have more benefits than the risk of mercury poisoning.

Your Dog Is Allergic to Tuna

As stated above, it’s always best to speak with your vet before adding new foods to your dog’s diet. Your dog can develop intolerance to any food, just like humans and if you notice anything unusual, immediately visit the animal emergency room near you.

Start with very small quantities and watch for any signs of distress. This could include lethargy, vomiting, or diarrhea.

Your Dog Isn’t Ready for New Foods

When you get a new puppy, it is always advised to keep them on the same type of food, be it from the pet store or the breeder – unless that food is particularly poor. This is because you already know that the food is safe for your dog.

As they grow, it is best to stick with the same brand of food and limit their exposure to human foods. For puppies, it’s not unusual to see adverse reactions to new foods, so it’s a good idea to hold off on feeding them tuna until they mature.

Which Types of Tuna Are Safe for Your Dog?

There are three main forms of tuna you might consider feeding your dog. These include canned, cooked, and raw. Each has its own set of pros and cons, and it will be up to you to make the final choice. However, we’ll go over each below to help you make the most informed decision.

Canned Tuna

As the name suggests, this type of tuna has undergone industrial processing and is packed in a can for marketing. It is available in almost all grocery stores and has a long shelf life.

This type of tuna is inexpensive, highly nutritious and can be found packed in either water or oil. Tuna packed in oil is usually higher in fat and calories than when packed in water, so is not the best choice if you have a dog breed that is prone to obesity, such as Golden Retrievers. However, you also need to note that canned tuna is also higher in sodium when compared to fresh tuna and when packed in water, it usually has more docosahexaenoic acid.

Depending on how tuna is packed, the nutrient content can vary between brands. You are advised to check the label to find the one with the least sodium and calories.

Below are the advantages and disadvantages of canned tuna.


  • Some canned tuna brands are inexpensive. If your budget for your dog food is limited, this is a great option.
  • Canned tuna keeps for longer. Most brands are known to have a shelf life of between 2-5 years. This is an advantage since dogs should only be given small portions of tuna.
  • Low in calories. This benefit only applies to tuna packed in water and can aid in weight loss for your pup.
  • It is minimally processed. Most brands try to reduce the processing, making them as close to raw tuna as possible.


  • Some brands have broth or seasoning. While this may be good for human consumption, these additives are not suitable for your dog.
  • Tuna packed in oil has more fats. This is not good for your dog’s cardiovascular health as it leads to increased weight.
  • Canned tuna is known to have sodium. Sodium is not good for your dog’s health. This could occasion excess sodium in the dog’s blood leading to hypernatremia.
  • Safety concerns of the cans. If not properly sanitized before packaging, cans can be a source of contamination which could affect the health of both humans and pets.

Raw Tuna

Unprocessed and uncooked tuna has many health benefits but just as many downsides in some people’s eyes. It depends on where you stand in the raw food diet argument.

Although your dog has a strong stomach, and the acid can kill bacteria and aid digestion, raw foods can be challenging for some dogs to digest. If your dog struggles with this, you may find that it can cause intestinal parasites.

Whether to give your canine raw tuna or not depends on your dog’s medical history, the size and age of your pup, and the source and quality of the fish.

Below are a few advantages and disadvantages of feeding your dog with raw tuna.


  • Small tuna fish have low mercury concentrations. The chances of mercury poisoning are lower in smaller tuna fish that haven’t lived as long. These should be safe to feed raw.
  • Has no food additives. This is a top health benefit for your canine as you don’t need to check the label for anything unnatural.
  • Has no risk of excess fats. Tuna is an excellent option for dogs looking to cut calories.


  • Small sharp bones can pose a health risk to your dog. If you are not diligent when it comes to deboning your tuna, you run the risk of your dog ingesting a bone. This can lead to choking or internal injuries caused by the piercing of the sharp bones.
  • It can carry intestinal parasites. Raw tuna can be infested with parasites which can endanger your dog’s health.
  • It can have adverse health effects on some dogs. Your dog could be affected by raw tuna and manifest symptoms such as weight loss, diarrhea, fever, vomiting, and swollen abdomen.

Cooked Tuna

The last choice you have here is cooked tuna. Cooking tuna is beneficial since it eliminates possible parasites which could otherwise cause a health risk to your pup. However, it is time-consuming and may not be the best option if you run a busy household.

Below are a few advantages and disadvantages of feeding your dog with cooked tuna.


  • Cooked tuna reduces the effects of infections. Just like we cook chicken to remove anything that may harm us, cooking your tuna will ensure it is safe for your dog to consume.
  • It offers the chance to blend other food items. Cooking tuna for your dog is beneficial since it gives you the chance to add other dog feed to the meal before serving your pup. This may go a long way to enhance the nutritional value of the food for your dog.
  • You can remove dangerous bones. Before cooking your tuna, you have the chance to remove all bones from the fish. It will also be easier to see them in the cooked fish.


  • If the tuna is cooked elsewhere, packaging can pose a contamination risk. Like with any other packaged food, cooked tuna can acquire contamination during the packaging process or from the packages. This may lead to a health concern for the dog.
  • It is time-consuming. If you have a DIY plan, you may find it time-consuming to prepare and cook your dog’s tuna.

How To Feed Your Dog Tuna

If you are still curious and hoping to give your dog the health benefits of tuna, you’ll need to know the best way to introduce it to their diet. Once you have consulted with your vet and purchased the correct kind, it’s not just a matter of adding it to your dog’s bowl.

Below we will cover the important facts to bear in mind when introducing your dog to tuna.

Feeding Your Dog Tuna for the First Time

As already stated, avoid feeding new foods to puppies. They have very sensitive stomachs, and it’s not uncommon to see certain foods give them negative side effects. Tuna, especially, being rich and fatty, may cause your puppy to vomit or have loose stool. You’ll see similar symptoms if they enjoy a bone too early.

To give your dog tuna for the first time:

  • Feed them a small amount. Don’t get overly excited and feed your dog too much – spoonful is enough, to begin with.
  • Monitor your dog for signs of illness. Your dog might react to the new meal with some form of allergy, diarrhea, or vomiting, so be sure to take note of any changes in health, mood, and behavior.
  • Don’t feed tuna to your dog every day. While tuna is beneficial to your dog, feeding it daily isn’t a great idea. Instead, try adding tuna to their dinner once or twice per week.
  • Consider your dog’s weight and size. The bigger and the heavier the dog, the higher its nutritional needs. For example, you can give a large pitbull more tuna than you would a Yorkie.

For context, a can of tuna should last your 20-pound (9.07 kg) dog for three weeks. On the other hand, the same quantity would only last five days if your pup is 90 pounds (40.82-kilogram).

To Feed Canned Tuna

When choosing canned tuna, ensure it is in date and packed in water. Ideally, it should be low in sodium and have no garnish or seasonings, such as salt, onion, or garlic, which are all very dangerous to your dog’s health.

If you can only find tuna that is packed in oil, be sure to drain it thoroughly and pat it dry with a paper towel.

To Feed Raw Tuna

If you are looking into a raw diet, you’ll know that you need to include a variety of food. This could be raw beef, eggs, and vegetables. Since your dog needs plenty of protein, tuna is a great addition when used in moderation.

Be sure to remove all of the bones and wash the fish before adding it to the bowl.

To Feed Cooked Tuna

Cooked tuna is more time-consuming, but you will have peace of mind knowing that it is safer for your dog. When looking to add cooked tuna to your dog’s diet, look for tuna steaks and remember that they do not need seasoning. The best way to cook your tuna is to boil or bake it before allowing it to cool so you can double-check for stray bones.

Should You Mix Tuna With Other Dog Food?

Since you’re only supposed to give tuna sparingly to your dog, you’re no doubt wondering if it can be mixed with their regular food. If you want to add fatty acids and fish proteins, surely you can simply mix it in with their kibble?

The answer is yes, you can and should mix tuna with other dog food. This will enhance the health of your pup and the taste of their kibble. Again, this should only be done as a treat and never for pregnant or breastfeeding dogs or puppies.

It Will Enhance Your Dog’s Nutrition

Like human beings, a lack of essential nutrients may cause your pup to become ill. If you are not using a top-quality dog food brand, chances are, your dog is not getting the nutrients it needs.

At this point, you need to enhance the nutritional value of your dog’s meal. A small portion of tuna is the ideal choice to add vitamins and minerals, along with much-needed protein.

You can do this once a week or a fortnight, depending on the needs of your pup. Remember to keep a keen eye on any possible effects on your dog.

It Will Encourage Fussy Eaters

It’s not uncommon for dogs to become bored of their food. This can happen at any time, but especially if they have been sneaking other foods. If you notice your dog not eating their meals, it may be time to add something else to their bowl. If you don’t want to try new brands of kibble, a spoonful of tuna might do the trick.

We, however, advise that you do this with caution and, better still, with your vet’s guidance. This is because your dog may have other underlying problems that may need some medical attention. If they are still not eating, you should bring your dog in for tests.

It’s also important to note that you should only add tuna to dog food if it does not already have tuna in the mix.

It Is Great for Variety

Many dog owners choose to make their own dog foods. They do this so that they can be in complete control of what their dogs are eating and know that it is healthy and well-balanced.

While this could be okay with some breeds, it may not be the same with your dog. Some dogs are very intolerant of human foods, and it is not safe to give them anything.

However, if you have had success with this, adding some tuna to your food regime will certainly be beneficial. Just remember to not make it a habit and introduce the new food slowly.

Signs of Possible Mercury Poisoning in Your Dog

Though unlikely, it is still important to know the signs of mercury poisoning if you are going to be feeding your dog tuna. If you are feeding small amounts, as recommended, symptoms may not appear until a few weeks after the first bite.

You should know these symptoms and be on the lookout for them, as early intervention is key. These symptoms are not a grave risk to your dog’s life when caught early, but you also do not want them to suffer needlessly.

We highly advise you to see your veterinarian as soon as you notice any of these symptoms:

  • Bloody or watery diarrhea
  • Vomiting blood
  • Loss of coordination
  • Loss of hair
  • Tremors
  • Blindness
  • Lack of feeling in the paw
  • Abdominal swelling
  • Difficulty urinating
  • Anxiety

Diagnosis of Mercury Poisoning in Your Dog

In the event you have been feeding your dog tuna inappropriately, and you notice any of the symptoms above, tell your veterinarian as soon as possible and stop feeding your dog tuna right away. Just remember that it may take up to two months for any signs to manifest after exposure.

Your vet will do a complete examination, which will involve checking your dog’s breathing, pulse rate, temperature, and blood pressure. They will also check the weight and height of your pooch.

Secondly, further tests will be done, such as fecal culture, fecal flotation, urinalysis, blood chemical analysis, blood count, and blood gases. If needed, to get a small sample of your dog’s kidney for a kidney biopsy, a fine needle will be used. CT scans, abdominal ultrasound, and MRI may also be done to evaluate the extent of the possible damage.

In case your dog’s nervous system is damaged, an electroencephalogram is performed to check its brain activity.

Treating Your Dog With Mercury Poisoning

Once it is known beyond any reasonable doubt that your dog has mercury poisoning, it will be hospitalized. After that, it will be given the following:

  • Oxygen therapy. This will enhance lung function, brain protection, and blood health.
  • Antibiotics. These will clear any possible infections caused by bacteria and enhance wound healing.
  • IV fluids. In the event a surgical procedure is carried out, these fluids help to maintain your dog’s electrolytes, blood sugar levels, and maintain hydration.
  • Anti-inflammatory medicine. These relieve pain in your dog.

Further, to bind and enhance the excretion of mercury from the dog’s body through urine, your vet will use a chelation medicine like dimercaprol or penicillamine and activated charcoal. Your pooch will be closely monitored for any signs of negative reaction to any of these measures.

Your Dog’s Recovery From Mercury Poisoning

Unfortunately, it is not possible to medically reverse mercury damage on your dog. Any damage to the renal system, liver, nervous system, or even the heart is permanent. When the dog is severely incapacitated and its quality of life is low, dog owners often choose euthanasia.

However, dogs rarely suffer to this extent from mercury acquired from tuna. Your best option is to keep anything with mercury far away from your lovely pooch and only feed it tuna sparingly.


Hopefully, after reading this, you can make an informed decision on whether or not to feed your dog tuna. It has some amazing health benefits, and the chances of mercury poisoning are very low. Its nutritional value and what it can offer your dog are much higher than any fears associated with tuna.

If you choose to include tuna in your dog’s diet, remember to do so sparingly and slowly. Never give tuna to puppies or pregnant or breastfeeding mothers.

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