Can Cats Eat Tuna?
Many cats enjoy the taste of tuna, and it can be offered as an occasional treat in small amounts. However, tuna prepared for human consumption should not become a regular part of a cat’s diet. It lacks the specific nutrients cats require to be healthy, and it is not a substitute for a properly formulated cat food.
A cat’s daily meals must consist of a complete and balanced commercial cat food designed to meet their unique dietary needs. Extras like tuna should be considered special treats. Keeping these treats to a minimum helps ensure your cat gets the right nutrition from their main meals and avoids potential dietary imbalances.
Tuna and cats: the facts in one table
| Verdict | Only plain, small amounts, with care |
|---|---|
| How to offer it |
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| Remove or avoid |
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| Main risks |
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| Signs to watch |
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What makes tuna tricky for cats
The main issue with feeding tuna to cats is nutritional. As obligate carnivores, cats have strict dietary needs that are different from those of people or dogs. Their bodies are designed to get specific nutrients from animal-based protein. Commercially prepared cat foods are carefully formulated to provide this complete nutrition.
Tuna intended for people does not contain the correct balance of vitamins, minerals, and other nutrients that a cat requires. Feeding it as a primary food source can lead to serious nutritional gaps. Another concern is the potential for mercury exposure. Tuna can contain mercury, and if a cat eats it frequently, this metal can accumulate in their system over time.
How to offer tuna and what to leave out
When offering tuna as a treat, choose the plainest option available. A small amount of tuna canned in water is the best choice. Before serving, carefully read the ingredient label to confirm there is no added salt, spices, or other flavorings. Simplicity is key to safety.
Some preparations of tuna should always be avoided:
- Tuna in oil: The added oil contributes extra fat to your cat’s diet, which is unnecessary.
- Tuna in brine: This type of tuna has a high salt content that is not appropriate for cats.
- Tuna salad: This dish is typically made with ingredients like mayonnaise, onions, or garlic, which can be harmful to cats.
It is also wise to avoid offering raw tuna. When you introduce any new food, begin with a very small piece and watch your cat’s reaction. Remember that tuna should not be a regular or large part of their food intake.
When it is best to skip tuna
For some cats, it is best to avoid tuna completely. If your cat has a sensitive digestive system or is on a veterinarian-prescribed diet for a specific health issue, introducing new foods can cause problems. Sticking to their approved diet is the safest course of action. Similarly, for cats with known food allergies or those managing their weight, the extra ingredients and calories in a treat like tuna are best avoided.
Always supervise your cat when they are eating a new food for the first time. Before adding anything new to your cat’s diet, including occasional treats, it is a good practice to consult your veterinarian. They can provide guidance based on your individual cat’s health profile.
When to call your vet
Most cats who eat a little plain tuna need nothing more than watching. Call your vet if anything below shows up, or if your cat has a health condition or is on a special diet.
If your cat consumes a large amount of tuna, especially tuna in oil or with added ingredients, monitor them for signs of an upset stomach. These can include vomiting, diarrhea, or abdominal discomfort. Contact your veterinarian if you see these or any other unusual behaviors.
For specific questions about potential risks like mercury, your veterinarian is the best resource. You can also contact the ASPCA Animal Poison Control Center for guidance.
Emergency signs: go now
- Collapse, fainting or severe weakness
- Seizures, tremors or trouble standing
- Trouble breathing or blue, gray or very pale gums
- Repeated vomiting or retching, or a swollen, painful belly
- Any known contact with a substance listed as toxic, even before signs appear
Book an appointment soon
- Vomiting or diarrhea that lasts or keeps coming back
- Not eating or drinking, or drinking much more than usual
- Drooling, pawing at the mouth or a swollen face
- Lethargy, hiding or acting unlike themselves
ASPCA Animal Poison Control Center: (888) 426-4435 (a consultation fee may apply). Your own vet or nearest emergency clinic is always a good first call.
Sources
Last checked October 21, 2026. Listings and guidance can change; your veterinarian knows your pet’s health history.