2 min 22 sec
The joy of interaction is a term we use to represent an idea that we are trying to create in the dog's mind. Basically, through play we are trying to create an experience that holds more value than any other experience, and this is something that needs to be taught or shown to most dogs.
With the help of the leash, we are able to control the dog's behavior immediately after we allow them to win the toy. In the beginning, the dog will most likely win the toy and leave the interaction to go "be with it," so we want to make it clear to the dog that if they bring it to us, we are going to play with them---and that they will win the toy again. By continually repeating this protocol, the dog ends up cherishing the feeling of winning the toy even more than the feeling of owning the toy after it has won it.
After you have allowed the dog to win the tug, the idea is to back away from them in order to invite more play. If the dog chooses otherwise, we can simply use the leash to gently reel them back in to us. When they get withing the appropriate distance, we can reach for the toy and begin playing again. Upon the production of a "power move" by the tug (yanking, thrashing, forward re-grip, etc.), we then release the tug and back up again to invite more play. Sometimes this might take a couple reps before the dog gets hip with the idea, but it can usually be taught within the first session.
3 min 47 sec
I'd just to touch a bit more on the use of leash pressure. By having a leash on the dog all the time, we can ensure that we are always there to reinforce the things we want. It's important to remember that we don't want to get into chase or keep-away games in our play, which is the polar opposite of the idea we are trying to create, so the leash plays a huge part in the teaching process.
Usually, everything done with the leash is done in a subtle, nonchalant kind of way, and I believe the dog more or less forgets about the leash it is dragging around. This works to our advantage because we don't want to be directly involved with what is happening with the leash. You almost want to make it as though there are two sides to you as a handler: a side that handles the leash, which is unemotional, tranquil, and calm in movement and touch, and another side that is happy, trustworthy, always patient, and rewarding of any type of engagement.
These two sides, while functioning simultaneously, must also function independently. Each side must be in perfect tune with the dog and its current state of mind, continually shaping both the behaviors we want to enhance, as well as the behaviors we want to dilute. This might sound complicated, but after trying it, you'll see that it is much easier to achieve than one might think.
2 min 46 sec
We can also use the leash attached to the toy to build and shape some of the innate traits in the dog, such as prey drive and play drive. The leash can really help to bring life to the toy (prey) and the play in general, especially in the beginning. It allows us to move the toy along the ground in a fast, fluid way, without us having to run all about the place trying to make that happen. It also allows us to set the grip once the dog has bitten the toy---again, without showing the dog any potentially adverse pictures. An example of behavior you'd like to avoid would be a dog bolting out of the immediate area when it sees you coming in to reach for the toy.
For many dogs, I will actually start with a leash attached to the collar and a leash attached to the toy. This turns you into a master puppeteer very quickly! This skill takes some time to develop, of course, but by applying the two-leash technique, you avoid any and all chances of the dog experiencing unwanted behaviors without the necessary applications of positive and/or negative reinforcement.