Welcome to Yorkietalk and congratulations on your baby. I'm not sure why breeders recommend giving nutrical as a daily supplement. That is sort of like saying give sugar to a baby daily to prevent diabetes. It should not be used as a preventative and should be saved for when the pup is actually hypoglycemic. Regular food and rest are the best ways to prevent hypoglycemic episodes.
For potty training, keep in mind that Yorkies need more than 3 potty breaks a day, especially when they are young. If you visit the training section, you will find lots of threads with tips on housebreaking. There is also a "sticky" thread at the top of the training forum. Whichever method you choose, be consistent and be sure to praise your pup for each correct potty.
__________________ Kristin, Max and Teddy  |