Age to start

I personally work mine very early and often but it is all about having them in the right situation, like goose said it is very easy to ruin a young dog by attempting to force it to do something it is not comfortable with. I use my ace in the hole, a track/ bay crazy jack russell gyp named yeti. from the time pups are weaned off their mom she becomes their new mother/mentor and quickly bonds with them, she lives with/eats/sleeps with them 24/7 in a 50x70 puppy yard. I tote both her and them to the woods at 10-12wks of age on mock hunts and let them run and play and just be puppies following her around until she picks up the track and brings em right to the shoat......she goes crazy and well then its simply puppy see, puppy do! I have have excellent results using this method the last 4 rounds of pups that i have raised, working them like this has been a game changer for me.