I've got the similar problem mate, i took a gamble buying the pup i bought with him being a bull whippet X JRT he's 7 1/2 month now, and i'm just taking him out with other running dogs and letting him watch, when he see's a bunny he's not that intersted yet, but that's just the pup in him, let him be a pup mate, you wouldnt ask a 3-4 year old child to go to work, it's just the same, give it time mate, let me know your progress as i'm in the same prediciment as you. cheers