Cat (and dog) food is trash. It's basically (tongue in cheek) ground-up newspapers and pressure-cooked old tumours
. What makes it so irresistable to animals is the powerful odourants added which drives their olfactory senses wild. It's the same kind of flavour they put in cat treats. You could sprinkle that stuff on chunks of shag carpet with a dropper and cats/dogs will eat it like it's prime rib dinner.