I don't know how, since both of my guys are on Revolution and only go out on a leash, but I found a tapeworm near Angus' butt. I've already called the vet and am picking up a prescription to treat both Angus and Leo. My question is the litter boxes. I'm assuming that a complete change of the litter and a thorough cleaning of all the boxes are a necessity but when? Should I wait until they've finished their medication or go ahead and do it this weekend while they're on the meds? I'm picking up some Droncit today so they'll start it this afternoon.