Right now my diet mainly consists of tuna, so I decided to check on what risks there could be for eating too much when I heard about too much tuna killing a cat from my stepfather. It turns out that, while the amount of mercury is relatively low in tuna, eating too much can become a health risk. Much like with ingesting too much fluoride.
I have no idea if about two cans a day is too much. Probably is. XD