From: fan

Unless there is another reason for
giving W/D, aside from "holding it down", it shouldn't be necessary to
continue it, in my personal opinion.

Check with your vet first before taking stranger's advice about changing from a
Prescription Diet to something else.

IF the problem was hairballs,
there are premium cat foods with additives already in them. Also there
are over-the-counter additives if the food doesn't already contain
them.

To my knowledge, there aren't ANY "hairball foods" that have additives in them
with the express purpose of controlling hairballs.