Hypoglycemia is the medical term for low blood sugar. Breeders often refer to this as sugar shock. This is a potential problem in all Yorkshire Terriers, and especially young ones. My experience is, that sugar shock is more prone to occur in Yorkie puppies between 5 to 9 weeks. That is why a teacup Yorkie needs to be held past the usual 8 weeks sale date. This is more so true if the Yorkie puppy is being shipped. A plane ride or even a car ride, can be very stressful on these little Tea Cup yorkies.
If a puppy gets a cold, or is stressed for any reason, or plays for long periods of time, they can experience a drop in sugar. If your puppy acts tired and sleepy, if they refuse food for a meal or two, or they act lethargic, act immediately by giving them a little honey, or the solution that I have sent with your yorkie puppy. Call a veterinarian if your Yorkshire Terrier dog doesn't respond pretty quickly. You can also call me.