Teaching your dog to stay is, comfortably, one of the most valuable dog assets your dog can have over the course of their life. It's so, so valuable to have confidence that in any given situation you'll be able to get your dog to remain in one position in a calm, relaxed frame of mind.
Understanding the mechanics of teaching a dog to stay is, therefore, one of the best uses of your time as you begin the journey of teaching your young dog to become a model canine citizen as an adult and throughout the rest of their life.
Here's a great video insight in to teaching the valuable command.
