I found you can break most lurchers if not from a pup but some terriers never grasp it-I was given a black pup from a lining off my old dog-got him at 5 months old-kids opened ferret court one day,ferrets walked through a block of my terriers past two lurchers into the last run that the black pup was in-came home all my dogs silent and in boxes-the little black prick was bouncing around his run-my best Jill was half eaten in his kennel -he had to go-only use my terriers for digging but I like them to be 100%-nothing worse than being invited out and your dog mullers someone's ferrets if your ra