taffyboy,,try these,,,just let it carry it put it on lead nd let it carry it till its board,OR,, get two balls or dummys throw one when it retreves nd you have hold throw other it may let go nd fetch other,maybe,,my mates bull x that did this nd i used to put my fingers near its mouth nd say ouch as though it had bitten me it allways let go but it just depends on dog,some i would not risk that ploy,lol hope this helps,atb mick