Re: Teaching drop it
I know you specified without food, but there's a quick and easy way to teach "drop it" and you don't have to use food for very long.
I take some people food - small cubes of cheese, bits of meat, etc. - and I put several in my mouth. You don't have to do this in front of the dog if you prefer to hide it (I don't mind the dog knowing, but some people are concerned about using food and having the dog focus on it too much). Then I play tug with the dog, and when I want her to let go I say "drop it" and then immediately start spitting the food onto the top of the dog's head. I don't wait for her to let go - I want her to think that "drop it" means "treats fall down fast on you".
Every dog I've ever used this with lets go of the tug and gobbles up the treats. While they're doing that, you can put a few more treats in your mouth and then immediately re-engage the dog in tugging play. Do the whole "drop it and treats fly down on you" exercise again, and repeat that every time you practice "drop it" for several days. By that time, your dog is probably spitting the tug out quickly on command in expectation of the food.
And then I just stop using the food for the most part (although I tend to use a treats for random reinforcements during retrieves anyhow, so the treats do come into play sometimes after a "drop it" command). In order to maintain the anticipation of reward after the dog lets go of the tug toy, you can throw the toy or another toy, or use some other reward that the dog really likes.
Dogs don't usually want to let go because they know that it ends the game - where's the fun in that? You can force them into letting go, but I've found that the treat-spitting exercise keeps enthusiasm and interest high - and it works great!
Melanie and the gang in Alaska
Positive 1ST! More reward, less correction makes a GREAT trainer.
Chows: Khana CD RE SD & Dora NA NAJ GSD: Tazer SDIT
Total of 2UDs 3CDXs 12CDs 2REs 8AgilityTitles 1BH Chow!
20 Yrs Training/Teaching Experience