Doc has said (if you search the posts here) that no superbugs are created IF you stay on the dewormer. Superbugs are "mutated" bugs, but what I think you are asking is if the bugs get resistent to the dewormers. The resistence is created when one goes on a dewormer and then stops and lets the bugs multiply and then goes back to kill them off again. This means more generations of the bugs to deal with. Then they may get a little tougher to kill. I think the thought is maintained here on this forum that if you stay on a dewormer all the time, this doesn't happen.