How long is opened wet cat food good for in the fridge?

The FDA’s own pet food safety guidance is simpler than most owners expect: refrigerate or throw out unused canned or pouched food promptly, and keep it tightly covered while it’s stored. It does not give a fixed number of days for good reason, since it depends on the food and your fridge. As a practical rule most owners use, a covered container of opened wet food is worth using within about two days and worth a sniff test before serving after that. If it smells sour, looks separated or your cat suddenly refuses a food she normally eats, that is your signal to toss it rather than push through.