Why
A small amount of tuna as an occasional treat usually causes no more than mild stomach upset. Fed regularly, tuna for people can cause steatitis, a painful inflammation of body fat. Tuna in complete cat food is fine.
How to serve tuna
- Choose tuna packed in water, not oil or brine.
- Offer a teaspoon or so as a rare treat.
Watch out for
- Do not feed it every day.
- Cats can get hooked on the taste and refuse their normal food.
How much tuna can a cat eat?
Treats of every kind should stay under 10% of a cat's daily calories. Here is that daily treat budget by size, and how much tuna it buys if tuna is the only treat that day. Tuna has about 86 kcal per 100 g; 1 oz (28.4 g) is about 24 kcal.
| Cat size | Daily treat budget | Max tuna a day |
|---|---|---|
| Small cat (6 lb) | 18 kcal | 21 g (two thirds of oz) |
| Average cat (10 lb) | 26 kcal | 30 g (one oz) |
| Large cat (14 lb) | 34 kcal | 39 g (one and a half oz) |
Less is better for overweight or diabetic cats. Work out your own cat's numbers with the cat food calculator. Calories: USDA FoodData Central, Fish, tuna, light, canned in water, drained solids (Includes foods for USDA's Food Distribution Program).
Other meat, fish and eggs: quick answers
| Food | Verdict | Short answer |
|---|---|---|
| Bones | Avoid | No. Bones can injure or block a cat's gut, which may need surgery. |
| Fat trimmings and skin | Avoid | Best avoided. Fatty scraps can cause stomach upset and pancreatitis. |
| Meat baby food | Avoid | Best avoided. Meat baby food is often seasoned with onion or garlic. |
| Raw meat | Avoid | Best avoided. Raw meat can carry Salmonella and E. coli. |
| Eggs | Small amounts | Cooked egg is the only option to consider; raw eggs are a no. |
| Chicken | Safe | Yes. Plain, thoroughly cooked chicken with no bones, skin or seasoning is a safe treat. |
| Fish | Safe | Yes, if it is cooked, plain and boneless. Raw fish is best avoided. |
| Salmon | Safe | Yes, cooked and plain. Raw fish is not a good idea for cats. |
Rules for any new food
- Plain is the rule: no salt, butter, oil, onion, garlic, sugar or sweeteners. Most of the danger in human food comes from what is added to it.
- Keep all treats under 10% of your cat's daily calories . The rest should come from a complete cat food.
- Check labels for onion and garlic powder, which turn up in stock, gravy, baby food and seasoned meat.
- If your cat has a health condition, such as diabetes, kidney disease or a sensitive stomach, ask your vet before adding any new food.
Frequently asked questions
Is tuna safe for cats?
Only a little, once in a while. Tuna made for people should not be a regular part of a cat's diet.
How much tuna can a cat have?
Treats of any kind should stay under 10% of a cat's daily calories. For an average 10 lb neutered cat that is about 26 kcal a day, or roughly 30 g of tuna if it is the only treat that day.
Sources
- PetMD, "Human Foods That Are Dangerous for Cats" (reviewed by Nicole Silva, DVM)
- Pet Nutrition Alliance, "Calculating Calories Based on Pet Needs"
- USDA FoodData Central, SR Legacy (April 2018 release)
Checked October 17, 2026. We are a reference, not a vet: if in doubt, call yours. How we check.