Can cats eat tuna?
As a rare treat, yes — tuna in its own juice, not in oil or brine. As a staple it is unsuitable: mercury load, unbalanced nutrients and its almost addictive appeal argue against it.
Why tuna for cats?
Hardly any food makes cats as weak as tuna — the intense smell is irresistible to many. Occasionally and in small amounts, tuna in its own juice is fine. As a regular food it is problematic: tuna is a predatory fish at the top of the food chain and accumulates mercury, and plain canned tuna is neither balanced nor fortified with the nutrients a cat needs. Some cats also fixate on the strong taste and start refusing their normal food.
How much is okay?
A teaspoon to a tablespoon at most, no more than once a week. Tuna must remain the exception, not the rule — the smaller the cat, the smaller the amount.
How to feed it?
Only tuna in its own juice or water, without salt, oil, spices or sauces. Drain it well. Unsuitable are tuna in oil, in brine, with tomato or spices, and raw tuna. Cat food with tuna is the safer alternative, as it is supplemented to be complete.
Risks & caution
Regular tuna feeds mercury exposure, an unbalanced diet (too little vitamin E, wrong calcium-phosphorus ratio) and picky eating. Salted or oil-packed varieties additionally strain kidneys and weight. Cats with kidney disease should not get tuna at all.
Can kittens have tuna?
Not for kittens: their small body weight makes them more sensitive to mercury, and their diet needs to be precisely balanced. Stick to kitten food.
Signs of intolerance
After a lot of tuna, digestive upset is possible; with chronic overfeeding, coat and nerve problems from mercury. If your cat refuses normal food after tuna treats, pause the treats consistently.
Related foods
Frequently asked questions
Can cats eat canned tuna?
Occasionally a small amount of tuna in its own juice, well drained. Tuna in oil or brine is unsuitable.
Why is tuna problematic as a staple?
It accumulates mercury, is not nutritionally complete and can make cats refuse their normal food. As a staple it harms in the long run.
How much tuna is okay?
A teaspoon to a tablespoon at most once a week — as a treat, not a meal.
Is raw tuna allowed?
No. Raw fish can contain thiaminase, which destroys vitamin B1, plus parasites. Only cooked or canned in water.
My cat only wants tuna — what now?
Stop the tuna treats consistently and mix a mini amount under the normal food at most, reducing further. The fixation usually fades within days.
Important note
This article never replaces veterinary advice. If you suspect poisoning or symptoms persist, contact your vet or the emergency veterinary service immediately.
Sources: General veterinary recommendations on feline nutrition; guidance on mercury in predatory fish. Last updated: 08/2026.
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