Light Tuna

I think my sister accidentally fed my cat light tuna instead of his cat food. I was a little worried, so is a little ok? My sis realized eventually that she fed the wrong food because of the strong smell, so my cat didn't eat ALL of the can. The ingredients on the can were: light tuna, water, salt in that order.

Should I be worried?

nope not in my opnion

Not just one time...if it were nightly instead of his food, I'd worry , but not in this situation.

The cat probably thought he had gone to heaven! Most cats love tuna and it is fine occasionally.