Can dogs eat canned tuna?

A small amount of tuna canned in water with no added salt is fine occasionally. Skip oil-packed and brine-packed versions, and anything flavored — the fat and salt cause more immediate trouble than the mercury.

Why is mercury a problem for dogs?

Tuna are large, long-lived predators, so they accumulate more mercury than smaller fish. Dogs are smaller than us and portions add up faster, so regular tuna feeding builds the dose week after week.

How often can I give my dog tuna?

There's no established safe schedule, which is itself the point — keep it an occasional treat measured in small bites, not a routine protein source. Smaller fish do the same nutritional job without the accumulation question.

What fish is safer than tuna for dogs?

Smaller, shorter-lived fish — sardines, cooked salmon, white fish like cod. They deliver the same omega-3s with far less mercury, which is why they're the standard fish in commercial dog foods.

Can Dogs Eat Tuna? Vet-Sourced Answer

Can Dogs Eat Tuna?

Feed with caution

Only occasionally, in small amounts. Tuna carries more mercury than most fish, and it accumulates in a dog's body over time.

Quick facts

Quick facts
Verdict	Caution
Risky amount	No safe or toxic dose is established — treat any amount as a risk.
Key symptoms	Vomiting or diarrhea (rich or oil-packed tuna), Excessive thirst (salty brine), Tremors or incoordination (chronic mercury buildup — rare), Loss of appetite
What to do	A stolen bite of tuna is not an emergency. If a dog that eats tuna regularly develops tremors, wobbliness or other unusual neurological signs, call your vet.

Why tuna is a sometimes-food

Tuna isn’t toxic to dogs — a stolen chunk of your sandwich is a non-event. The caution is about repetition. Tuna are big, long-lived predatory fish at the top of the food chain, which makes them one of the higher-mercury fish people commonly eat. Mercury accumulates in the body, and a dog’s smaller size means the same “harmless” portion is a much bigger relative dose, meal after meal. Chronic buildup is rare but serious, showing up as neurological signs like tremors and incoordination.

Choose tuna canned in water with no added salt, or plain cooked fresh tuna — never oil-packed, brined or seasoned versions, and no raw tuna (see raw fish). Keep the portion small relative to your dog and make it an occasional event, not a habit. Cats famously get in trouble with tuna-heavy diets; dogs are simply less often given the chance.

Better fish for the routine

If your dog loves fish, feed the small stuff: sardines, cooked salmon or white fish deliver the same omega-3 benefits with a fraction of the mercury. Save tuna for the odd shared bite.

If your dog ate it

A stolen bite of tuna is not an emergency. If a dog that eats tuna regularly develops tremors, wobbliness or other unusual neurological signs, call your vet.

In the US you can also call the ASPCA Animal Poison Control Center at (888) 426-4435 (a consultation fee may apply).

Frequently asked questions

Can dogs eat canned tuna?: A small amount of tuna canned in water with no added salt is fine occasionally. Skip oil-packed and brine-packed versions, and anything flavored — the fat and salt cause more immediate trouble than the mercury.
Why is mercury a problem for dogs?: Tuna are large, long-lived predators, so they accumulate more mercury than smaller fish. Dogs are smaller than us and portions add up faster, so regular tuna feeding builds the dose week after week.
How often can I give my dog tuna?: There's no established safe schedule, which is itself the point — keep it an occasional treat measured in small bites, not a routine protein source. Smaller fish do the same nutritional job without the accumulation question.
What fish is safer than tuna for dogs?: Smaller, shorter-lived fish — sardines, cooked salmon, white fish like cod. They deliver the same omega-3s with far less mercury, which is why they're the standard fish in commercial dog foods.