Dear Christopher Cat
I offer my cats various brands of dry and canned cat foods, but Smokey, my old guy, prefers the same canned tuna I eat. Is this okay?
As long as tuna comprises less than 10 percent of Smokey’s diet, it’s probably fine. But it sounds like he’s eating more than that.
A diet that contains a significant amount of tuna isn’t balanced. Too much tuna is bad for us for many reasons:
- We cats need large quantities of B vitamins, but tuna has only small amounts, which are further reduced when the tuna is cooked during the canning process.
- Tuna contains enzymes that break down vitamin B1, also known as thiamine. Insufficient thiamine causes neurologic and gastrointestinal problems.
- Tuna also is deficient in vitamin E. Insufficient vitamin E can cause pansteatitis, a painful, debilitating and sometimes fatal inflammation of the body’s fat.
- Internal bleeding due to vitamin K deficiency has been reported in cats eating canned tuna. Some cats have bled to death.
- Tuna is low in calcium and other important minerals.
- Conversely, tuna is high in magnesium, which may increase the risk of feline lower urinary tract disorder.
- Some tuna is contaminated with mercury, which can cause neurologic problems when ingested in excess.
Entice Smokey to eat more of his balanced-diet cat food by offering him less tuna.