Few smells are as appetizing to cats as tuna. While canned and fresh fishy treats probably won't harm your feline friend, excessive quantities can foster malnutrition and other issues. As such, it's probably best that you avoid feeding your cat tuna except as an occasional snack.
Cats are natural fish lovers, so it's of scant surprise they're drawn to the pungent aroma of tuna -- whether it's intended for them or not.
"Your cat will see an open can of tuna next to the sink as a dinner invitation," notes an article on WebMD, a popular health website. The site notes that "cats can be addicted to tuna."
All Things in Moderation
Tuna, itself, isn't bad for cats.
"An occasional tuna treat for your cat is generally harmless," says Mindy Bough, a veterinary technician for the American Society for the Prevention of Cruelty to Animals. "However, if a large part of the cat's diet consists of tuna -- or if the cat is fed tuna exclusively -- some problems are likely to arise."
Although it feeds their natural drives as obligate carnivores, cats can't survive on tuna alone because it lacks complete nutrition.
No Bones, No Value
A cat that eats tuna to the exclusion of other foods may suffer malnutrition.
De-boned fish, including processed tuna, lacks calcium, sodium, iron, copper and other vitamins -- all of which can create or exacerbate cat health issues.
One form of malnutrition, vitamin E deficiency, causes steatitis (yellow fat disease). Symptoms include loss of appetite, fever and hypersensitivity to touch. If your cat shows these symptoms, call a veterinarian immediately.
Because few if any single-source diets have complete nutrition, many veterinarians recommend feeding your cat premium commercial or homemade cat food.
Tuna, quite infamously, can have high levels of mercury. Over time, or in acute doses, this can be harmful to your cat; it's best to limit the animal's access to it.
Your cat's lust for tuna can be an asset, though, not just a liability. If the animal isn't warming up to new food -- and you're sure the cat doesn't have an underlying medical condition -- a sprinkle or two of tuna water can help whet her or his appetite.
The same trick works when administering medicine.