FaunaHub

Cats Food Safety

Can Cats Eat Tuna?

Depends — cautionModerate risk

Direct answer

It depends — a very small amount of plain tuna, occasionally, is sometimes considered acceptable for healthy adult cats. Tuna is not a recommended regular food, and it is not a complete diet for cats. The main cautions are added salt and oil, the highly palatable nature of tuna (which can make cats picky), mercury concerns at higher exposure levels, and the risk of nutritional imbalance if tuna becomes a major part of the diet.

Why this matters

Cats are obligate carnivores, and plain tuna provides animal-source protein. A small amount occasionally is therefore often tolerated.

Tuna is highly palatable. Some cats develop a strong preference for tuna and will refuse complete-and-balanced cat food in favour of it. This is a real risk because tuna alone does not meet feline nutritional requirements.

Canned tuna products vary widely. Tuna in salted brine or in oil adds sodium and fat that cats do not need; tuna with added flavourings or sauces (onion, garlic, herbs) is not appropriate.

Large predatory fish, including tuna, can accumulate environmental contaminants such as mercury. Occasional small servings are generally not the same risk profile as tuna-heavy diets, but it is one more reason to keep tuna an exception rather than a routine.

Preparation cautions

  • If offered at all, choose plain tuna packed in water with no added salt or flavourings — not tuna in brine, oil, sauce, or marinade.
  • Do not offer tuna mixed with onion, garlic, chives, or other seasonings.
  • Do not let tuna replace complete-and-balanced cat food. Use it as a small occasional topper or treat at most.
  • Wash any utensils or surfaces in contact with raw tuna; do not feed raw tuna casually.

Quantity caution

A small spoonful of plain water-packed tuna as a rare treat is very different from a tuna-based diet. Frequency, amount, and whether tuna is appropriate at all in your cat's diet are decisions for your veterinarian — particularly if your cat has kidney disease, urinary issues, or other chronic conditions.

Warning signs to watch for

Any of the following signs warrant prompt veterinary contact — particularly if more than one appears, if they persist, or if they appear after a known ingestion.

  • Vomiting or diarrhea after tuna
  • Refusing regular complete-and-balanced food after tuna treats (a sign of selective eating)
  • Lethargy or unusual behaviour after eating tuna
  • Symptoms after eating brine- or oil-packed tuna, or tuna with added seasonings

When to call a veterinarian

If in doubt, call. Contact a veterinarian if your cat develops persistent gastrointestinal upset after tuna, refuses complete cat food in favour of tuna, has any chronic condition affecting diet, or accidentally consumed flavored or oil-packed tuna in a meaningful amount.

Safer alternatives

  • Plain cooked, unseasoned chicken in small pieces
  • Plain cooked, unseasoned turkey in small pieces
  • Commercial cat food (wet or dry) labelled as complete-and-balanced
  • Commercial cat treats designed for the species

Frequently Asked Questions — Tuna & Cats

Can my cat have canned tuna every day?
No — tuna is not a complete-and-balanced food for cats, and feeding it daily can lead to nutritional imbalance and selective eating. Tuna is at most an occasional small treat.
Is tuna packed in oil okay?
Oil- and brine-packed tuna add fat and salt that cats do not need. If you offer tuna at all, plain water-packed tuna with no added salt is the better choice — and even then, in very small amounts.
What about cat foods that are tuna-flavored?
Tuna-flavored cat foods that are labelled as complete-and-balanced are formulated for cats and are generally appropriate. They are different from feeding human canned tuna, which is not formulated for feline nutrition.
What about mercury?
Larger predatory fish, including tuna, can accumulate mercury and other environmental contaminants. Occasional small servings of plain tuna are not generally considered a major mercury concern, but tuna-heavy diets are one more reason to keep tuna an occasional treat rather than a staple.