Can dogs eat tuna? I smell something fishy

Can dogs eat tuna?

Can dogs eat tuna? If you are one of the many people that sit down to enjoy a tuna sandwich for lunch, then you may find your dog trying to convince you to share it with them.

If you can’t resist those pleading eyes and want to share your favourite food with your dog, then it’s worth knowing the benefits and the risks of giving your dog tuna.

The benefits of tuna

Like all fish, tuna is an excellent source of lean protein and is packed full of healthy fats, vitamins and minerals. Rich in vitamin C, zinc, manganese and selenium, tuna is a great way of providing all you need to boost the immune system.

Not only that tuna is a great source of omega-3 fatty acids that contribute to overall health and will ensure that your dog has a beautifully shiny coat.

Fish is a low-fat protein source and is easy to digest which makes it a healthy choice for dogs that are overweight or recovering from illness.

So if you want to treat your dog to some tuna,  you can, but stick to tuna packed in water. While alternative options include tuna packed in brine and oil, it’s best to keep away from them. On the one hand, it is high in salt which isn’t a healthy option for our dogs. On the other, please be aware that too much oil is likely to affect your dog’s digestive system adversely!

However, if you prefer to give your dog fresh tuna steak then as with any fish, make sure you thoroughly cook it first. Parasites can survive in raw fish, so cooking them will kill them off.

These parasites can be life-threatening to your dog so be on the safe side and make sure you cook it properly before offering it to your dog.

The risks of tuna

So what’s the downside? Well, the bad news is that tuna fish contains mercury. Mercury has been classified as a heavy metal, similar to iron and zinc.

However, unlike iron and zinc that carry out essential functions in the body, mercury has no business being in your body and is highly toxic.

Unfortunately due to pollution the fish that we eat are swimming in a less than clean oceans. When Mercury is introduced into our oceans, it gets converted into something called methylmercury by the natural bacteria in the water.

For large, long-lived fish like the tuna, it’s bad news. Not only do the tuna absorb poisonous mercury from the surrounding water they are swimming in; but when they eat smaller fish, they also get an extra dose.

Unfortunately, this means that tuna ingest a lot of heavy metal in the duration of their 15-30 year’s lifespan. In fact, reports suggest that tuna has been found to contain 10,000 times the concentration of mercury in their bodies than exists in their surrounding environment.

Don’t be fooled into thinking fresh is better either. Fresh tuna steaks contain even more mercury than the canned variety.

It’s a red herring

So why bother sharing your sandwich when there is such a risk. Moderation is the key. Although fish should never be the sole protein source for your dog, a small amount added to their diet can be a fantastic treat.

If you are concerned about the mercury levels in tuna, you could choose a different fish. Smaller, shorter-lived fish like anchovies, mackerel, haddock and herring contain much less mercury than tuna.

As with all new foods, introduce it slowly to your dog. Despite fish being easy to digest it can cause allergies so test with a small piece first.

You may find fish as one of the ingredients in commercial dog food. It’s there for a good reason, the benefits of eating fish are well documented, (which is the reason why the manufacturers include it!).

So, can dogs eat tuna?

Yes they can, the fish itself is a tasty treat. However, it should only be given in moderation because of the mercury levels.

If you want to include fish in your dog’s diet, then experiment with other fish or try one of the tasty recipes below.


Tuna or Salmon Fudge 


  • 2 x 6-oz cans undrained tuna or 1 x 15-oz can of undrained salmon (look for salmon that is deboned)
  • 2 eggs
  • 1 ½ cups flour
  • ¼ cup parmesan cheese
  • 1 – 2 tsp garlic powder*


  1. Mix all ingredients together and press into a greased 9” x13” pan (mixture will be stiff).
  2. Bake at 350º for 20 minutes.
  3. Remove from oven and let cool.
  4. Cut into narrow strips; then dice strips into small cubes. Refrigerate or freeze.

*Garlic can be toxic to dogs. Avoid garlic in your dog’s diet generally, but be particularly careful to avoid large quantities of fresh garlic. Ask your veterinarian if garlic seasoning is appropriate for your pet. Alternatively just leave it out of the recipe and make your fudge garlic-free!

Homemade Turmeric and Fish Gourmet Dog Treats


  • 300g organic oats
  • 65g organic turmeric
  • 270g sardines in oil – two tins
  • 2tbsp organic wholemeal flour; heaped
  • 1tsp black fresh cracked pepper
  • 1tbsp organic cold pressed virgin coconut oil; heaped
  • 1 egg
  • 100ml fish stock


  1. Preheat the oven to 180C and line two large trays with baking paper.
  2. In a large bowl place the oats, flour, turmeric, pepper, egg and sardines and stir. Add the coconut oil and pour the hot stock over the top of it all (this will help to melt the coconut oil).
  3. Continue to mix all the ingredients until well combined but remember to wear gloves if you are doing it by hand. The first time I made these cookies I didn’t wear any gloves and my hands were a lovely yellow/orange for days afterwards despite multiple washing and soakings in the hope of getting rid of the colour.
  4. Once your dough is well-combined, move it onto a work surface, and roll out flat until your mixture is about 0.5cm thick.
  5. Use a cookie cutter to give your treats the desired shape and place on the lined baking tray. I wanted to make a lot of small cookies, little and often, as it ended up we do not own any small cookie cutters so I was using an upside down shot glass to make my cookies.
  6. Bake in the earlier preheated oven for around 20 minutes. As with any baking, they will be ready when they have turned a pleasing golden colour, and they should be firm to a light finger press.
  7. Remove from the oven and let them rest for 5 minutes before placing on a cooling rack to allow them to cool completely.

Four Herb Tuna Tots


  • 1 1/2 cup rolled oats
  • 1 cup cornmeal
  • 1/2 cup whole wheat flour
  • 1/2 tsp dried dill
  • 1 tsp dried oregano
  • 1 tsp dried thyme
  • 2 tsp dried parsley
  • 5 oz can tuna in oil (do not drain)
  • 3 tbsp extra virgin olive oil
  • 1/4 cup water
  • 1 egg


  1. Preheat oven to 350° F
  2. In a large bowl, whisk together the oats, cornmeal, flour and herbs.
  3. In a blender puree the tuna, oil, water and egg.
  4. Make a well in the centre of the oat mixture and pour in the tuna mixture.
  5. Stir until combined.
  6. Lightly spray a baking sheet with non-stick cooking spray.
  7. Using a 1-inch cookie scooper, pack the dough into the scooper with your hands and release on the baking sheet.
  8. Bake for 25 minutes.
  9. Cool completely on a wire rack.

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