[Ellie May]

How long ago did the vomiting and not wanting to eat start?
Can she hold down food and water?
Is she pooping liquid or is it formed?

Even a day of not wanting to eat may necessitate testing (when they are vomiting and sick, not when a Yorkie is just being picky).

Are you sure she isn't dehydrated? Honestly in the US if they start vomiting and go off food, it is considered an emergency very quickly. Hours of vomiting or a day off of eating and tests start to get ran. If not and there is an obstruction, the intestines can start to die off. If it's pancreatitis and the dog keeps eating, the pancreas will continue to eat itself. If it's IBD, the inflammation continues without treatment. If it's pyometra, death can occur quickly. IF it's a bacteria and the antibios don't clear it quickly, sometimes supportive care (IV in the hospital) is needed, etc., etc., etc.

I'm not sure what the vet meant by wanting to wait and err on the side of caution. That is erring on the side of danger. Her stress level over having tests done doesn't matter at this point. It didn't matter a day after this started. What matters is that she gets diagnosed and treated before she dehydrates and crashes on you. My dogs routinely gets bloods done. They also sometimes have to have xrays. And they do fine with it...

If there are ANY signs of dehydration I would get this dog to the ER now. That's probably where she should be anyway. Perhaps she should be on an IV while a diagnosis is being made. Vomiting all the time and not wanting to eat every other day is very, very serious.