Can Dogs Eat Canned Tuna

The Short Answer: In Very Small Amounts Occasionally — But Not Regularly

Canned tuna is not toxic to dogs in small amounts, but it is not a food you should give regularly. The primary concern is mercury — tuna is a large, long-lived fish that accumulates mercury in its flesh, and regular consumption can lead to mercury toxicity in dogs. Canned tuna in water (not oil) with no added salt is the safest option if you choose to share it, but even then, only in very small amounts and infrequently.

Why Canned Tuna Should Be Limited for Dogs

1. Mercury Accumulation — The Primary Concern

Tuna is a large predatory fish that sits high on the food chain. It accumulates mercury from the smaller fish it eats throughout its long lifespan. Mercury is a heavy metal that is toxic to dogs and accumulates in the body over time. Regular consumption of tuna can lead to mercury toxicity, causing:

• Neurological symptoms — tremors, loss of coordination, blindness
• Kidney damage
• Digestive problems
• Hair loss
• Anxiety and behavioral changes

Albacore (white) tuna has significantly higher mercury levels than skipjack (light) tuna. If you share canned tuna with your dog, choose canned light tuna (skipjack) over albacore.

2. High Sodium in Most Canned Tuna

Canned tuna packed in brine or with added salt is very high in sodium. Always choose canned tuna in water with no added salt for dogs. Even "no salt added" varieties contain some natural sodium.

3. Tuna in Oil

Canned tuna packed in oil adds significant fat, raising pancreatitis risk. Always choose tuna in water, not oil, for dogs.

4. Thiaminase in Raw Tuna

Raw tuna contains thiaminase, an enzyme that destroys thiamine (vitamin B1). Canned tuna is cooked during processing, which inactivates thiaminase — making canned tuna safer than raw tuna in this regard.

When Canned Tuna Is Acceptable

A small amount of canned light tuna in water with no added salt, given occasionally (once a week or less), is unlikely to cause harm in a healthy adult dog. It provides omega-3 fatty acids, lean protein, and B vitamins. The key is moderation and choosing the right product.

How to Safely Give Canned Tuna to Dogs

• Choose canned light tuna (skipjack) — lower mercury than albacore
• Packed in water — not oil or brine
• No added salt — check the label
• Small amounts only — a teaspoon for small dogs, a tablespoon for large dogs
• Infrequently — once a week or less
• Drain thoroughly before serving

Safe Fish Treat Alternatives

👉 Natural Balance Limited Ingredient Rewards Crunchy Biscuits with Real Salmon — dog-specific fish treats made with real salmon and formulated for canine health. All the fish nutrition without mercury concerns or sodium overload.

👉 Pet Oil Omega 3, 6, 9 for Dogs — provides the omega-3 fatty acid benefits of fish without the mercury risk. A safer way to deliver fish-derived nutrition to your dog daily.

The Bottom Line

Canned tuna is not toxic to dogs in very small, infrequent amounts, but it should not be a regular treat due to mercury accumulation risk. If you share it, choose canned light tuna in water with no added salt, give only a small amount, and limit to once a week or less. For regular fish-based nutrition, choose dog-specific fish treats or omega-3 supplements that deliver the benefits without the mercury risk.