Early scent introduction (ESI) is a training program for puppies designed to enhance their ability to identify, and react to, specific scents. For practical purposes, this means our puppies have a greater potential to grow into better companion, service, and therapy dogs. Scent abilities are often very important. 
Just as an example, when a dog is a companion to a child with autism, the dog's main function is likely to be a guardian of sorts. If the dog is able to easily follow the child’s scent and locate them, that could actually be a life-saving asset.

What is Early Scent Introduction? image