Hi from Rowdy's Mom - I'm so glad that your baby is better. I'm glad you called the vet too, it sounds like everything will be OK and if not, then you can call him back, anytime, like he said.
I know that I panicked the first time my baby had diarrhea and wouldn't eat. He was only 9 weeks old and sooo tiny. I grabbed him up so fast and took him to the vet. I'm lucky now though, that I live in the city and have that option, day or night.
And yes, licking the nutrical is my "gauge" with Rowdy. If he will lick the nutical, then I'm not in the panic mode - but when he won't lick it, I know he feels very badly because nutrical is his very most special favorite treat in the whole wide world!
Of course, that doens't mean that he might not be very very sick and still lick nutrical - but at least I know that he will be taking in some nutrition when he will lick it and won't get hypoglycemic.
Anyway, it is always better to be safe than sorry - I bet vets joke about their crazy Yorkie Mom's calling all hours of the day and night. But you know what - I DON'T CARE!!! (I am glad when they answer the phone or call back though!
Keep a close eye on your little one - you are a GREAT Yorkie mom!!!