Giving Puppies the Best Start: ENS and ESI Explained

Puppies grow fast, and those first few weeks of life play a huge role in shaping the kind of dogs they’ll become. That’s why many breeders are turning to proven early-development practices that set puppies up for success. Two of the most impactful are Early Neurological Stimulation (ENS) and Early Scent Introduction (ESI)—simple, short exercises that build stronger bodies, sharper minds, and greater confidence. 

Early Neurological Stimulation (ENS) is a simple set of exercises developed by the U.S. military to give working dogs a head start in life. The process involves gently handling young puppies between 3 and 16 days of age in specific ways—such as holding them upright, placing them on their back, and lightly stimulating their paws. Each exercise only lasts a few seconds, but together they expose the puppy to mild, controlled stressors that encourage stronger development of the brain and nervous system. The benefits are long-lasting: studies show that ENS puppies often grow into dogs with stronger immune systems, better stress tolerance, and improved problem-solving skills compared to those who don’t receive it. So while ENS was originally designed to produce more resilient military and service dogs, those same benefits extend to companion dogs as well—helping family pets grow into well-adjusted, confident adults.

The 5 ENS Exercises:

• Tactile stimulation: Gently tickle the bottom of one paw with a cotton swab for 3–5 seconds.

• Head held erect: Hold the puppy upright, with its head pointing toward the ceiling, for 3–5 seconds.

• Head pointed down: Hold the puppy securely with its head pointing toward the floor for 3–5 seconds.

• Supine position: Place the puppy on its back in the palm of your hand for 3–5 seconds.

• Thermal stimulation: Place the puppy belly-down on a cool, damp cloth for 3–5 seconds.

Early Scent Introduction (ESI) is a training method designed to complement Early Neurological Stimulation (ENS) by focusing on a puppy’s sense of smell. With their eyes and ears closed for the first two weeks of life, puppies rely solely on their sense of smell. Between 3 and 16 days old, puppies are briefly introduced to a new scent each day. Herbs, various materials, or natural items are held near the puppy’s nose for a few seconds to allow them to investigate. The goal isn’t to force interaction but to provide gentle exposure during this key developmental window. Research shows that puppies who participate in ESI often grow up with stronger scenting abilities, better adaptability to new environments, and greater confidence—benefits that are valuable not only for working and service dogs but also for family companions.

At Harpers Ferry Doodles, we incorporate both Early Neurological Stimulation (ENS) and Early Scent Introduction (ESI) into our daily care routine because we believe small, intentional practices make a big difference. These short, simple exercises help our puppies develop stronger bodies, sharper minds, and calmer temperaments—setting the foundation for a lifetime of confidence and adaptability. Whether they grow into loyal family companions or working partners, our goal is to give every puppy the very best start so they can become the best dog they’re meant to be.