"Leave it" is often a misused and undertrained behavior. Too often trainers do not break down this complex behavior into small, manageable pieces and end up saying "leave it," but then yanking on the leash.
I have broken this down into many logical approximations, and take it to the real world. It is all well and good that your dog can "leave it" during a training session, but can they "leave" the pill you accidentally dropped? The puddle that may have antifreeze in it? The poop on the trail? This webinar will provide you with a toolbox to successfully work on it.