I usually start doing this early on. When I am sitting on a hog before I tie it. Make a barrier between the pup and the hog with your hand or hat. Tell them back in a stearn voice. May even have to push them back. Continue this treatment after the hog is tied. Tell them back and put yourself between them and the hog. May have to force them back with your body. Dont give in and let them at it.
They will usually get the point at some point and loose interest after the you have the hog. Eventually they will get to where they will ignore tied or trailored hogs.
Some dogs you may have to be a bit more agressive with or may take more time. Just remember you dont want it to be negative. Just have to show them it is your hog and they have to get their own.
