I would not personally eat a cat, but that's a matter of cultural upbringing and not because it's ethically wrong. Because, frankly, if it's not ethically wrong to eat pigs, it's not ethically wrong to eat cats or for that matter dogs. As Davros pointed out, pigs are a magnitude of intelligence above the rest mentioned, and indeed above pretty much all common household pets that people might find it revolting to think of as a meal.
There is a point of intelligence though where I would consider it wrong to eat an animal. Or for that matter do anything else to it except out of pure nessecity, including keeping it in captivity. I can't really say there's any scientific base for that opinion of mine, but it's there nonetheless - Suffice to say, past a certain point I consider it a sort of "professional courtesy" to not willfully do harm to a species. The number of animals that are intelligent enough that I consider them in that class are very few though, and as far as I know none of them are eaten anyway.