The short answer: It is not recommended.
The long answer: Similar to dogs, cats should not consume tuna on a daily basis. Tuna is a type of fish that contains high levels of mercury and metals in its body. This is because it lives longer compared with other fish. Feeding tuna to your cat regularly may lead to mercury poisoning. It can manifest as loss of coordination, loss of balance, and difficulty in walking. Tuna is also packed with unsaturated fats that could cause inflammation of the fatty tissue.
Be wary of serving your cat tuna in raw, canned, or brined forms. Raw tuna may contain bacteria such as salmonella, which can make your cat sick. Canned tuna, on the other hand, may have other ingredients that are toxic for him. Examples include garlic, chili, and preservatives, to name a few. Meanwhile, brining contains high levels of salt, which is not recommended for your cat.
What to do if your cat accidentally eats tuna: Check the nutrition label or find out the ingredients used to cook the tuna. If it contains toxic ingredients for your cat, get in touch with your veterinarian immediately. Observe her for signs of poisoning: salivation, vomiting, diarrhea, twitching and fitting, difficulty in breathing, shock or collapse. Inflammation or swelling of the skin, depression, coma, and changes in drinking, urinating, and appetite may also occur.
In summary: Cats are obligate carnivores, so their diet should consist mostly of animal-based protein. Unfortunately, tuna is not included in this category. If you want to serve fish to your pet cat, choose salmon and sardines instead of tuna. Clean the fish properly, remove all the bones, cook it without any flavourings or heavy sauces, and serve it to her sparingly.