Can Dogs Eat Tuna?
⚠️ In moderation — with a couple of catches
Tuna contains high levels of mercury that can build up with regular feeding — small amounts of light tuna in water as an occasional treat only, never oil-packed, salted, raw, or to puppies.
Maybe — a tiny amount of plain light tuna packed in water is OK as a rare treat, but tuna is genuinely a caution food. The real issue is mercury: tuna is a large, long-lived predatory fish and accumulates more mercury than salmon or tilapia. Canned tuna in oil can cause pancreatitis, raw tuna can carry parasites, and tuna should never replace a balanced meal — PetMD says outright: don't feed tuna to puppies at all.
How much tuna can my dog eat?
A 30-lb adult dog needs about 794 kcal/day, so treats should stay under 79 kcal. That's up to about 2 ounces of canned tuna in water a day as a treat.
A treat limit (10% of daily calories), not a target — assumes an adult dog. Puppies and special diets: use the full calculator.
PetMD's specific guideline: very small amounts as an occasional treat — and it should not be your dog's main source of nutrition or a regular ingredient. The calculator gives a calorie-based per-serving ceiling for water-packed canned tuna, but frequency matters most: think a teaspoon or two now and then, not weekly.
Is tuna good for dogs?
Tuna is genuinely high in protein and omega-3 fatty acids — the same nutrients that make salmon a healthy fish for dogs. The catch is mercury: tuna sits higher on the food chain than salmon or tilapia, and AKC notes 'the larger the fish and the longer it lives, the higher the concentration of mercury in its tissues.' So the protein and omega-3s are real, but you can get them from safer fish.
How to serve tuna
- Water-packed only — never tuna in oil. Drain the water before serving.
- Plain only — no salt, no seasonings, no garlic, no onion, no sauce. AKC explicitly flags canned tuna's added salt and preservatives.
- Always cooked, never raw — even canned tuna is already cooked. Raw seafood can carry parasites and bacteria.
- Treat only, not a meal replacement — PetMD explicitly says tuna should not be a main source of nutrition or a regular ingredient.
What to avoid
- Tuna packed in oil — PetMD says it can cause an upset stomach and lead to pancreatitis. Water-packed only.
- Salted or seasoned canned tuna — AKC flags added salt and preservatives. Plain, water-packed, drained only.
- Regular tuna feeding — mercury bioaccumulates. AKC: 'the larger the fish and the longer it lives, the higher the concentration of mercury in its tissues.' Tuna is bigger and longer-lived than salmon or tilapia.
- Raw tuna — parasites and bacteria. Cooked (or already-canned) only.
- Tuna with garlic, onion, lemon, mayo, or any seasoning — tuna salad, tuna casserole, tuna sushi with sauce. Garlic and onion are separately toxic to dogs (see our garlic and onions pages).
- Tuna for puppies — PetMD is explicit: do not feed tuna to puppies at all, even occasionally.
💡 What next?
Common questions
- Canned tuna in water vs in oil — which can my dog have?
- Water only. PetMD says tuna packed in oil 'can lead to pancreatitis in dogs' and is more likely to cause an upset stomach than water-packed. Drain the water before serving, and choose a plain (no salt added) variety if you can find it.
- How much tuna can my dog eat, and how often?
- PetMD's rule: 'very small amounts as an occasional treat.' That means a teaspoon or two now and then for a medium dog, not weekly. The calculator above gives a calorie-based per-serving ceiling for water-packed canned tuna — but frequency matters more here than portion size, because mercury accumulates over time.
- Can dogs eat raw tuna?
- No. PetMD: 'Raw seafood can contain harmful bacteria and/or parasites that can cause illness in dogs.' Stick to cooked or already-canned (cooked) tuna only — no tuna sashimi, poke, or tartare.
- Can puppies eat tuna?
- No — PetMD is explicit: 'Do not feed tuna to puppies, even if it's just a tiny bit on rare occasions.' Mercury bioaccumulates and puppies' developing systems are more vulnerable. Stick to puppy food and safer treats.
- Why is mercury in tuna a concern for dogs?
- Tuna is a large, long-lived predatory fish that sits higher on the food chain than salmon or tilapia. AKC: 'the larger the fish and the longer it lives, the higher the concentration of mercury in its tissues.' Small one-off amounts are fine, but regular feeding lets mercury build up — and chronic mercury exposure can damage kidneys and the nervous system.
- What if my dog ate a whole can of tuna?
- PetMD: 'If Fido happens to steal an entire can of tuna, he might experience an upset stomach, especially if the tuna was packed in oil instead of water.' Watch for vomiting, diarrhea, lethargy, or loss of appetite. Oil-packed tuna can trigger pancreatitis — if symptoms persist or worsen, call your vet.
- Is tuna actually good for dogs?
- Nutritionally tuna does have real upside — PetMD: 'Tuna is packed with protein and omega-3 fatty acids, which are important nutrients for maintaining your dog's skin, coat, and joints.' The catch is mercury. You can get the same protein and omega-3s from salmon or sardines with much less mercury, which is why most vets recommend salmon over tuna for dogs.