When I was with the ASPCA, we did ENS (early neurologic stimulation) and special handling exercises for puppies from the age of 3 days to 16 weeks. It is important for puppies to meet and enjoy the interactions with many different people, play with other dogs and puppies, learn to tolerate all kinds of handling and experience everyday sights, sounds, smells, and sensations. I attached the explanation of all of these items. You may also use a tube sock filled with rice (and a knot in the end) to mimic littermates.
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