I'm trying to help a friend to teach hold to a 2 yrs old Male Lab. His obedience is very good, heels on both side, steady sit, here is good, but, when a mark is thrown he will drop the bumper on the way back. Now when started to work on hold it has become a battle of he just doesn't want hold the paint roller and practically have to wrestle with him. He rolls around on the grass/floor or tries to take the roller out with his front paw, does anything to not to hold it. Please help with this issue any good comments/suggestions will be greatly appreciate it. Thanks in advance.