Have no clue how to train one. I have a blue heeler that will blood trail providing people do not walk ahead or her. Seems that once the deer's track has been walked on, she gets confused. She is age 4 now, and was a better blood tracker at age 1& 2, but she only get a few chances per year, and lately the tracks have been walked on extensively. She is a herding dog and probably doesn't have the greatest nose. It sure is rewarding when she finds someones deer.