Final answer:
Begin the Heel cue when the dog maintains focus on the unbaited hand during movement transitions. This shows readiness for more complex tasks without treat-based incentives, an important step in service dog training.
Step-by-step explanation:
You would begin giving the Heel cue and expect the dog to move with you as you step forward once the dog can keep its nose attached to your unbaited hand as you change between the back-up exercise and the walking Heel. This indicates that the dog has developed the ability to maintain focus and understands the expected behavior without the lure of a treat.
This is an integral part of service dog training, where reinforcement of desired behaviors and gradual removal of bait (like treats) are key to developing a reliable service dog. Continuous positive reinforcement and increasing the complexity of tasks in small steps are crucial to successfully training service dogs to perform their roles effectively.