Can dogs eat tuna?

Caution — small amounts, not often

Small amounts of plain tuna (in spring water, not oil or brine) are fine occasionally, but tuna is high in mercury so shouldn't be a regular food.

The full picture

Tuna is safe for dogs in small amounts but isn't ideal as a regular food. As a large predatory fish, it accumulates mercury in its flesh, and frequent tuna consumption can lead to mercury poisoning over time — especially in smaller dogs. Tinned tuna is safest if it's in spring water, not brine (too much salt) or oil (unnecessary fat). Fresh tuna should be cooked plain. It's a useful 'emergency protein' if you've run out of dog food, but don't make it a habit. Salmon or sardines are better regular choices.

If your dog has eaten tuna

A small amount is fine. A whole tin of tuna in brine could cause salt issues — watch for excess thirst and contact your vet if concerned.

Risks to watch for

  • Mercury accumulation over time
  • Excess salt from brine varieties
  • Excess fat from oil-packed varieties

Potential benefits

  • High-quality protein
  • Omega-3 fatty acids
  • Most dogs love it

Safe portion size

A tablespoon once or twice a month for a medium dog.

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Safer alternatives

  • salmon
  • plain tinned sardines in spring water

Unexpected vet bills can run into thousands

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Related foods

Salmon yes Sardines yes Chicken yes
Written and reviewed by
The Can My Dog Eat editorial team

Every food page is cross-checked against UK veterinary sources including the Veterinary Poisons Information Service (VPIS), the Animal PoisonLine, PDSA, and the Merck Veterinary Manual before publication. We do not accept paid placements from brands. If you spot an inaccuracy, please let us know — we take errors seriously and correct them quickly.

Spot an error? Report it

Checked against UK veterinary guidance — see our editorial standards and source list. If your dog has eaten something and you need urgent advice, call a vet or the Animal PoisonLine on 01202 509000.

Important: This page is general information, not veterinary advice. Every dog is different, and individual factors (age, breed, health conditions, medications) can change what's safe. If in doubt, always contact your vet — or the Animal PoisonLine on 01202 509000 in the UK.