Some trainers, both positive and dominance-based, claim that head halters cause dogs to “shut down” and lose their “sparkle”. Any unpleasant experience with a training tool can make a dog shut down, whether that tool is a head halter, a buckle collar, a slip lead, or anything else. Since head halters take more adjustment to get used to than other tools, more dogs are rushed into it and therefore feel negative about the experience. If your dog turns into a robot dog and loses interest in everything when you put on any training aid, you are doing it wrong. If properly acclimated, your dog should come running in excitement when she sees her training tool.