✓ Reviewed against PDSA, Blue Cross & Animal PoisonLine guidance · Last reviewed: 2026-07
Can dogs eat tuna?
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 ate more than a safe amount
If your dog has eaten a large amount of tuna or tuna regularly, watch for digestive upset in the short term. Long-term concerns are mercury accumulation — switch to sardines or mackerel as a better-tolerated oily fish.
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.
Safer alternatives
- salmon
- plain tinned sardines in spring water
And while you're thinking about what's good for your dog, keeping on top of flea and parasite prevention is just as important as diet.
Common questions
Is tuna safe for dogs?
How much tuna can a dog eat?
What are the risks of tuna for dogs?
What should I do if my dog eats too much tuna?
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