My 6 month old lab is retrieving to hand great, which I have been working on hold, and she will hold. The problem is she likes to mouth the dummy or roll it around when she is holding. She has retrieved live and dead birds when introducing to birds and she is not hard mouthed or destroying the bird. All of her adult teeth are in so its not a teething issue. Have been following Hillmans program in teaching hold. Is there a way to stop the mouthing before force fetch to enforce the hold without discouraging the pup? Thanks to all.