Sometimes — with care
Cats adore tuna, and an occasional spoonful is fine — but a tuna-heavy diet causes real problems: mercury, vitamin E depletion, and stubborn “tuna addiction”.
Tuna is protein-rich but nutritionally incomplete for cats: it lacks adequate taurine balance, vitamin E and several minerals. Cats fed lots of oil-packed tuna can develop steatitis (painful yellow fat disease) from vitamin E deficiency, and tuna’s mercury levels are the highest of common food fish. There’s also the behavioural trap every cat owner knows: tuna is so palatable that some cats start refusing normal food — vets literally call them “tuna junkies”. Water-packed, plain, occasional: that’s the formula.
A teaspoon to a tablespoon of water-packed tuna once or twice a week as a treat or food topper is a sensible ceiling. Choose “light” tuna (skipjack) over albacore — about a third of the mercury. Never brine-packed, oil-packed, or seasoned.
Plain cooked chicken or commercial cat treats balance palatability with safety; sardines in water occasionally for omega-3.
Related: Can dogs eat tuna? · Can cats drink milk? · Can cats eat chicken?
This article is general information, not veterinary advice. If your pet has eaten something potentially harmful or shows symptoms, contact your vet or an emergency clinic immediately. Full disclaimer.