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If your cat comes running the moment you pop a can of tuna, you’re not alone. But can cats eat tuna, and is it actually good for them? The short answer: yes—when served properly and in moderation. Below, we’ll cover how tuna can support your cat internally, how much is safe, and the best ways to serve it without risking your cat’s health.

Key takeaways: can cats eat tuna?

  • Tuna can support internal health with high-quality protein and omega‑3s, but it should be an occasional treat—not a daily meal.
  • Choose tuna packed in water with no added salt; avoid oil, brine, and seasonings.
  • Stick to small portions: about 1–2 teaspoons up to 1 tablespoon, once or twice a week for an average adult cat.
  • “Light” tuna (skipjack) generally has less mercury than albacore/white tuna.
  • Raw fish can carry parasites and thiaminase risk; cooked or canned (in water) is safer.
  • Human tuna isn’t a complete diet—don’t let it replace balanced cat food.

How tuna helps cats internally

Tuna can be more than a tasty treat—served wisely, it can support several aspects of your cat’s internal health:

  • Lean animal protein: Helps maintain muscle mass, supports tissue repair, and fuels everyday energy.
  • Omega‑3 fatty acids (EPA/DHA): Found in fatty fish like tuna, these can support heart and brain function, help moderate inflammation in joints and skin, and promote a glossy coat.
  • Hydration boost (if packed in water): Many cats are chronically under-hydrated. A little water-packed tuna—or even a spoonful of “tuna water”—can encourage them to consume more fluids, which supports urinary tract health.
  • Appetite enticement: For picky eaters or cats recovering from illness, a tiny amount of tuna mixed into regular food can help stimulate appetite.

Important note: While tuna contains valuable nutrients (including some taurine and B vitamins), it does not provide the complete and balanced nutrition cats need long-term. Think “treat” or “topper,” not “total diet.”

The risks: why tuna should only be a treat

  • Mercury accumulation: Larger fish like albacore can carry more mercury. Over time, too much tuna can pose neurological and systemic risks. Opt for “light” tuna (skipjack) and keep portions modest.
  • Nutritional imbalance: Replacing complete cat food with tuna can lead to deficiencies (for example, vitamins and minerals that are specifically balanced in cat diets).
  • Sodium and oils: Many canned tunas contain added salt or are packed in oil. Extra sodium isn’t ideal for cats, and oil adds unnecessary fat that can upset the stomach or exacerbate pancreatitis.
  • Food safety: Spoiled fish can cause histamine (scombroid) reactions and GI upset. Store tuna safely and use promptly. Raw fish can carry parasites and enzymes that degrade vitamin B1; choose cooked or canned.
  • Picky eating: Too much tuna can make some cats reject their regular food, which leads to an unbalanced diet.

How much tuna can cats have?

Use the “10% treat rule”: treats—including tuna—should make up no more than 10% of your cat’s daily calories.

  • General guideline for adults: About 1–2 teaspoons up to 1 tablespoon of water-packed tuna, once or twice per week.
  • Kittens, pregnant, or nursing cats: Aim to avoid tuna due to mercury risk. If offered at all, keep it to a tiny taste on rare occasions—ask your vet first.
  • Cats with special conditions (e.g., pancreatitis, kidney disease): Consult your veterinarian before offering tuna, and avoid tuna in oil or with added salt.

Smart ways to serve tuna to cats

  1. Choose canned tuna in water with no added salt; avoid oil, brine, and flavorings.
  2. Rinse briefly under cool water to reduce any residual sodium if needed.
  3. Flake finely and mix a small amount into your cat’s regular food to enhance aroma and taste.
  4. Offer a spoonful of the “tuna water” to increase hydration—without overdoing the fish itself.
  5. If using fresh tuna, serve it fully cooked, plain (no onions, garlic, spices, or sauces).
  6. Refrigerate leftovers in a sealed container and use within 1–2 days.

Healthy alternatives that deliver similar benefits

  • Fish-based complete cat foods: Look for AAFCO-compliant wet or dry diets that include tuna or salmon and are formulated to be nutritionally complete.
  • Omega‑3 supplements for cats: Vet-approved fish oil (usually from anchovies/sardines) can support skin, coat, and joint health with controlled dosing.
  • Hydration hacks: Water-rich wet foods, cat-safe broths with no onions/garlic, and water fountains can help maintain urinary health.
  • Lower-mercury fish treats: Occasional sardines (in water, no salt) can be a good alternative—still in small amounts.

FAQs: tuna for cats

Can cats eat tuna every day?

It’s not recommended. Keep tuna as an occasional treat to prevent mercury buildup and nutritional imbalance.

Is raw tuna safe for cats?

Not advisable. Raw fish can carry parasites and enzymes that interfere with vitamin B1. Cooked or canned (in water) is safer.

Can cats eat tuna in oil?

Best to avoid. Oil adds unnecessary fat and can upset your cat’s stomach. Choose tuna packed in water with no added salt.

Is tuna water safe for cats?

In small amounts, yes. A spoonful can entice drinking and add flavor, but don’t rely on it daily.

How do I know if I’ve given too much?

Watch for vomiting, diarrhea, itchy skin, weight gain, or a refusal to eat regular food. If symptoms persist, consult your veterinarian.

Thinking about welcoming a playful new friend who’d love a treat-time topper now and then? Meet your match:

Cat - Playful Companion for Every Home

The bottom line

Tuna can be a tasty, motivating, and sometimes helpful add-on for cats—especially for hydration and omega‑3 support—but it’s not a complete diet and shouldn’t be a daily staple. Choose water-packed tuna, serve tiny portions only a couple of times per week, and when in doubt, ask your vet. Balanced nutrition first; tuna as a treat.

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