Can Cats Eat Tuna?
Caution — cats adore tuna, but tuna cannot be their diet: mercury build-up, an unbalanced nutrient profile, and "tuna addiction" are real problems. A fork or two of water-packed, unsalted tuna occasionally — that is the ceiling.
Last reviewed: July 24, 2026
Why moderation matters so much
Canned tuna made for humans lacks the balance a cat needs (taurine included); a cat eating mostly tuna develops deficiencies and mercury build-up over time. Its intense smell also creates strong preference — the cat that refuses everything but tuna is a classic story.
Raw tuna additionally contains thiaminase; regular raw fish can cause vitamin B1 deficiency. The rule: cooked or canned, in water, unsalted, occasional. Tuna-based cat foods are balanced products and can be used with confidence.
Frequently asked questions
My cat insists on tuna only — what should I do?
Rather than cutting tuna cold, mix it into regular food and shrink its share meal by meal, using the smell as bait. If the standoff continues, ask your veterinarian for a transition plan — a long tuna diet causes serious deficiencies.
Can I give the water or oil from the can?
A little of the water from a water-packed, unsalted can is fine. Skip the oil, and skip salty or sauced can liquids.
Is tuna cat food safe then?
Yes — cat foods are balanced with taurine and other nutrients. The problem is not tuna in cat food but human canned tuna becoming the diet.
Related answers
Sources
This guide is based on publications from the following veterinary bodies. Where sources differ, we take the more cautious position; the final decision is always your veterinarian's.