Can Dogs Eat Tuna? Canned vs Fresh Safety Guide

The Short Answer

Cooper discovered tuna when I dropped a forkful of salad on the floor, he was a fan immediately. But after researching mercury levels in tuna, I've kept it as a very occasional treat rather than a regular addition. Here's what you need to know.

Canned Tuna vs. Fresh Tuna

Canned Tuna

• Light tuna (skipjack), lower in mercury than albacore. This is the safer option if you're sharing with your dog.
• Albacore (white) tuna, contains roughly three times more mercury than light tuna. Best avoided for dogs.
• Choose tuna packed in water, not oil. Oil adds unnecessary fat and calories.
• Check the sodium content. Many canned tuna products are high in salt. Choose low-sodium or no-salt-added varieties.

Fresh Tuna

• Cook it thoroughly. Raw tuna can contain parasites and bacteria. No sushi for dogs.
• No seasonings. Plain, cooked tuna only, no garlic, onion, lemon, or soy sauce.
• Remove all bones. Small fish bones can splinter and cause choking or internal damage.
• Fresh tuna steaks (bluefin, yellowfin) tend to have higher mercury levels than canned light tuna.

Mercury Poisoning Symptoms in Dogs

Mercury poisoning from tuna is rare with occasional feeding but worth knowing about:

• Loss of coordination and difficulty walking
• Tremors or shaking
• Vomiting and diarrhea
• Hair loss
• Kidney damage (increased thirst and urination)
• Anxiety or nervousness
• Vision changes

If your dog has been eating tuna regularly and shows any of these symptoms, stop feeding tuna immediately and see your vet. Mercury poisoning develops gradually with chronic exposure, not from a single serving.

Safe Serving Guidelines

• Small dogs (under 20 lbs): 1 tablespoon of canned light tuna, no more than once every two weeks
• Medium dogs (20-50 lbs): 2 tablespoons, no more than once a week
• Large dogs (50+ lbs): up to 3 tablespoons, no more than once a week

Safer Fish Alternatives

If your dog loves fish, there are lower-mercury options that can be fed more frequently:

• Salmon, lower mercury, rich in omega-3s (always cooked, never raw)
• Sardines, tiny fish with minimal mercury accumulation and packed with nutrients
• Whitefish, cod, tilapia, and pollock are all low-mercury options
• Herring, excellent omega-3 source with low mercury

These fish provide the same protein and omega-3 benefits as tuna without the mercury concerns. Sardines in particular are an excellent choice, they're small enough that mercury isn't a concern, and they're packed with omega-3 fatty acids that support your dog's skin, coat, and joint health.

Related Reading

Wondering about other foods? Our complete guide to human foods dogs can eat covers dozens of common options. For more on safe vs. unsafe foods, see our toxic foods list. And if you're looking for healthy treat ideas, check out our guide to carrots and green beans as low-calorie alternatives.