Can Dogs Eat Tuna Fish? (Raw or Canned?) How Much Is Safe?

Can Dogs Eat Tuna Fish? Photo of a French Bulldog licking his lips with a can of tuna by his side.

If you’ve made yourself a delicious tuna salad or sandwich and want to share it with your dog, you might be wondering just whether or not it’s a good idea! Here’s what you should know.

Tuna isn’t toxic to dogs, but it does have the highest mercury count of all fish, meaning that the mercury content in the tuna can be dangerous for dogs. For this reason, dogs should not eat tuna fish, whether fresh or canned.

While a tiny little bit now and again is considered safe, it’s best to find alternative fish options to feed your dog.

Why is tuna safe for humans but unsafe for dogs?

Technically, tuna is dangerous for humans, too, in larger portions. However, mercury isn’t as damaging to us and our systems as dogs because of its size.

We require higher concentrations of mercury to cause toxicity. Since dogs, even larger ones, are smaller than the average human adult, it takes less mercury to cause toxicity.

Humans can safely eat tuna in standard serving sizes, whereas dogs cannot safely eat the same amount of tuna without the possibility of mercury poisoning.

Can dogs eat raw tuna?

No, raw tuna is very dangerous for dogs. On top of its mercury levels, raw tuna also contains a lot of parasites and bacteria that can make your dog sick. Raw tuna should never be given to your dog, even in small servings.

Can dogs eat canned tuna?

Whether you are considering giving your dog canned tuna fish in water or canned tuna fish in olive oil, both will be dangerous for your dog.

While cooked and therefore free of parasites and bacteria, both still have mercury amounts that make it unsafe for dogs to eat. Dogs should also avoid tuna steak, tuna pasta, and tuna salad. 

How much tuna is safe for dogs?

As far as your dog’s health is concerned, you don’t need to panic if your dog scarfs down a few bites of tuna from your plate. Thes won’t be enough to hurt him as long as it only happens once in a while.

Generally, you’ll want to make sure that you never feel a large dog more than a can of tuna over a week. This could be in the worst-case scenario as far as dosages are concerned, as you shouldn’t deliberately feed your dog tuna at any point.

Can a dog with pancreatitis eat tuna?

A dog with pancreatitis will benefit from omega-3 fats, which makes many people immediately grab a can of tuna and spread it on their dog food. However, as you’ve learned, the cons and potential risks of tuna will outweigh the advantages that are there.

Without question, omega-3s are good for dogs with pancreatitis. But tuna is still considered too dangerous for dogs due to the mercury content. More on the potential for omega-3s later!

Can tuna upset a dog’s stomach? 

Yes, tuna can upset a dog’s stomach, especially if it is canned with olive oil. Both are high in fat and rich foods so that it can create stomach upset. Fresh tuna can also upset a dog’s stomach because of the omega-3 content. 

Interestingly, it’s a great source of protein that doesn’t tend to be as hard to digest for dogs as some of the more traditional forms of protein, but the mercury makes it a bad idea.

Tuna can give dogs diarrhea, too, between its richness and potential for mercury poisoning (more on that in a bit.)

What to do if my dog eats tuna?

If your dog eats tuna, it’s not an immediate cause for concern. First and foremost, you’ll want to remove any tuna from around him to keep him from eating more. If you can interrupt him while eating, do so and take away anything he hasn’t yet eaten. The less he gets, the better.

From there on, you’ll need to start watching for signs of mercury poisoning in your dog.

Below are some of the symptoms that can tell you that your dog is struggling with too much mercury. They can occur altogether or one at a time:

  • Fur loss
  • Anxiety or nervousness that doesn’t quell
  • Sudden blindness
  • Incapable of urinating
  • Stomach swelling
  • Loss of coordination
  • Numb paws
  • Tremors or shaking
  • Vomiting blood
  • Watery or bloody diarrhea

If you see any or all of these, you’ll want to get your dog to a vet right away.

The other thing is that if you know that your dog’s consumed more than a can’s worth of tuna, or your dog is tiny, bring him to the vet to have him be tested for mercury poisoning so that he can receive care.

Benefits of tuna for dogs

Despite the danger of mercury poisoning, tuna is thought to have great benefits for your dog regarding the omega-3 content.

This helps with inflammation in your dog, if they have any, and it’s a reliable source of protein for those dogs that have an issue with digesting classic protein, like chicken or beef sources.

What’s the best way to serve tuna to dogs?

In an ideal world, not at all. Tuna is well-thought to have more risk than reward when it comes to your dog’s health and safety. But there will be some who simply want to do it anyway.

If you have your heart set on feeding tuna to your dog, however, and your vet has approved it in small doses, then you can do it carefully.

First of all, see it as a very rare treat. Once a month, and in very, very small servings. The smaller your dog, the less you should feed, and less frequently you should feed it. It should not be a part of their daily diet, no matter how small the amount is or how large your dog is!

As far as the tuna is concerned, you’ll want to make sure it is well cooked or that it is canned (preferably in water) and drained.

You can feed a few flakes at a time or mix with their food in tiny, tiny amounts. You can also mix it with gravy or another carrier to help spread it further to benefit your dog’s taste and safety.

Even in doing it as carefully as possible, you’ll still need to monitor your dog for signs of mercury poisoning closely. You’ll definitely need to take him in for regular testing and watch for the symptoms mentioned above.

Even in the best-case scenario, you’ll find most vets will be wary about dogs eating tuna, and most will recommend it for short-term use only. This prevents the likelihood of mercury build-up in the body. 

Alternatives to tuna for dogs

If you’re feeling apprehensive now, then you’ll be relieved to know that there are quite a few options that you can consider for dogs.

Some of the best fish options that will be much safer for your dog (and you) include:

  • Salmon
  • Arctic char
  • Flounder

You can also ask your vet about foods or supplements that you can feed your dog that will be easy on their stomach and still give them the omega-3s you’re looking for.

Vets often will be able to recommend safe doses of all of these omega-3s, too, which will help maximize the potential benefits and minimize any downsides.

Some dog experts will say that any kind of fish-based protein isn’t a good idea for your dog’s health. Still, it depends on your dog’s dietary concerns and your vet’s personalized advice. That’s why a vet is going to be such a helpful professional to ask for advice!

In General

Tuna fish isn’t toxic, but mercury can be very dangerous for dogs of all ages, sizes, and health profiles.

You’ll want to avoid feeding it to your dog without your vet’s explicit approval.

There are plenty of other safer choices for your dog’s omega-3 needs!

Dogs can eat tuna fish but shouldn’t, especially if your dog has health complications and concerns.

If you know someone who is known for sneaking this canned treat to their dog, consider sharing this with them to help keep everyone safe and sound!

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Writer, Editor and member of the Council, I am a dog person and I thrive to get the answers that will help you provide the best care a dog can have.