Hmm. I've got crossbred American cocker spaniel/ miniature poodles here. Two of them got next door, got into the pen, and killed my neighbour's two pet rabbits. Can't think the poodle part made them killers.Their dam, the cocker, kills rats and will certainly kill a rabbit, as her youngsters did, if she gets the chance.All of them go rabbiting in the woods around here.
However, it is just possible that , if your dog has never been allowed or encouraged to hunt AND is introduced gradually by you he won't attack it . Me, I wouldn't chance it because seeing the rabbit lolloping off might set off some hunting instinct in him.