When do you treat your cows for lice? Some folks recommend the pour or spray on lice treatment. Mine are starting to rub and scratch their heads and necks on the trees and wood fence posts. Here in MO the weather has been changing from 30 to 60 and back to 30! Guess the warmer temps are starting to bring out the bugs. Is it way too early for treatment? Is the pour-on or dust bag preferred?