Hi Dan,
Technically no - since defra say we shouldn't feed animal protein to them (try telling that to the hen running off with a worm!) and cat food contains animal protein from rabbit, chickens, ducks etc but it is a well known fact that during the moult, to give chickens a protein boost (needed for feather production) many old timers scatter a handful of dried cat kibble down as it is very high in protein and helps them to get over the moult faster.
Dog food can't be used since the source of protein is usually cereal based.