So I tried a little experiment last night.
Scorch and I were practicing obedience in a parking lot in Lakeland. We worked a couple of heeling patterns and the figure 8. I had the dumbbell out in sight and he was reasonably quiet. We broke off from heeling for a reward, except instead of a treat, I allowed him to tug for a few minutes.
I put the tug away and we moved on to dumbbell retrieves. He was much more on edge and even barked. He was also grabby with the dumbbell and I had that "barely contained" feeling that marked so many of our runs.
He loves tugging even more than treats. He'll go into my training bag and ignore an open bag of salmon goodies in favor of a felt tug. But it sends him over the edge.
What do I do? Do I stop tugging altogether for a while? Save it for the end? Tug and then try an exercise and put him away if he vocalizes? Practice exercises with the tug toy around but don't let him have it?
What do I do when his favorite reward makes him bonkers?