One of our male cats has recently started dragging his rear end on the ground. At first I figured he must have gotten a tapeworm somehow. All 9 rescue kities are indoor, on Revolution and have their litter cleaned often - but you know how things happen despite your best prevention efforts. Anyway, I took him to the vet and to my suprise - he came up fine. No worms, parasites, or anything abnormal according to the vet. I still keep a close eye when he uses the litter box and haven't seen anything (oh what we moms do, huh?). He continues to drag his rear and I am wondering if I should get a second opinion? Everything looks normal back there on the outside (no inflammation or anything) and he doesn't ever have anything stuck to him that he might be trying to wipe off (he doesn't leave streaks). Any thoughts? Is there something obvious I (and the vet) could be missing?