Some people have dogs with a nose for truffles. My cat Dugal has a nose for butter. Take a stick out of the frig, and his pleading cries for a piece commence! If I forget the butter on the counter, I’ll find him lapping it up like he’s been starving. He shows no interest of any level in other “human food.” If I ever suspected I’d been sold or served fake butter, I’m sure Dugal’s reaction to it would tell me the answer.