While we typically think of cats loving the taste of fish, it’s easy to forget that dogs are big fans, too. Dogs might love a meat-based diet but our canines will usually be happy to tuck in to fish and fish-based food, too. You can read more about why dogs like fish here.

However, this doesn’t mean that dogs can, or should, eat all types of fish. When you’re preparing a meal including fish, it’s highly likely that your dog will be pretty close by, showing a great deal of interest in what’s on your plate — no doubt with nostrils twitching in anticipation. So, can you share your fish supper with your pup? It largely depends on what type of fish it is. 

We’ve written a guide to whether your dog can eat seafood here, but we’re going to focus in depth on tuna. Can dogs eat tuna? Let’s find out.

This is difficult to answer definitively. Can dogs eat tuna? From research, it’s clear there are differing opinions — the American Kennel Club (AKC) advises that you shouldn’t give your dog tuna to eat  as a staple part of their diet.

Why? Well, while tuna is fine for dogs to eat in occasional, small portions, there’s a genuine concern about the level of mercury tuna contains.

As a large species of fish, tuna has a higher level of mercury than many other types of fish, so there’s a risk of a condition called mercury poisoning if you do feed it to your dog. Mercury poisoning can be a serious condition — even fatal — and it can affect humans too. The mercury level in fresh tuna is higher than when it’s been cooked, so you should definitely avoid giving that to your dog.

The symptoms of mercury poisoning can be varied, but typically include anxiety, tremors, vomiting and diarrhea and abdominal pain.

Yes, this does sound frightening — but if you’ve given your dog some tuna to eat, or your pup has nabbed some without you knowing, if it’s only a small amount there is no reason to worry. If your dog has consumed a lot of tuna, or has been eating it regularly over a period of time, as a pet parent you should be aware of the risk. Contact your veterinarian immediately if you think there’s cause for concern.

If you have a puppy, avoid tuna completely — even small amounts. Because puppies are smaller than full-grown adult dogs, the risk of mercury poisoning is higher.

There are different varieties of tuna, and some are safer for your dog to eat than others. This is because these different varieties of tuna have different levels of mercury within them. Skipjack tuna and light tuna have lower levels of mercury than yellowfin and bigeye tuna.

Another popular tuna type is albacore tuna. Can dogs eat albacore tuna? The answer is no, as albacore tuna has relatively high levels of mercury.

No. Dogs should never eat raw tuna, so if you’re preparing a tuna steak and asking ‘can dogs eat ahi tuna?’ the answer is no. Ahi tuna is traditionally served raw or rare, lightly pan seared at most, so it’s not suitable for dogs to eat.

In fact, dogs shouldn’t eat any type of raw fish as there’s a chance it contains bacteria and parasites; these are eliminated when fish is cooked, so it’s fine to serve to your pup. But raw fish of any sort is a total no-no; don’t be tempted to share your sushi lunch with your dog. 

Can dogs eat canned tuna? Yes. Tuna that comes in canned form is usually fine for dogs to eat, but there are some considerations to bear in mind.

Check the ingredients of any can of tuna carefully. Try to avoid any canned tuna that contains too much extra seasoning, preservatives and, especially, salt. Dogs need a certain amount of sodium in their diet but too much of it (in the form of salt) can have a negative effect on them, not least risking dehydration.

Something else: canned tuna tends to come in spring water, oil or brine. Always choose a version in water. Oil can upset your dog’s stomach, and brine is too salty. So, can dogs eat tuna in water? Yes — but not tuna in oil or brine.

Tuna — like a lot of fish — is a healthy type of food and can be beneficial for dogs, if fed in small amounts as an occasional treat. Tuna contains a series of vitamins, including niacin (B3), Omega-3 fatty acids and protein.

Remember, though, that your dog should be getting all the nutrients it needs from its regular dog food; your pup shouldn’t need extras. Read our guide to choosing the best food for your dog here.