Chihuahuas-9wks-vaccinations..… is it and what are side effects?

I don't give my chihuahua pups any of their shots until they are over a pound. They give the same dose to a 1/2 lb chi pup as to an adult St Bernard. Also you should keep the tiny pup until it is at least a pound. One thing you really need to watch for right now is hypoglycemia(low blood sugar). Specially with the little one. Buy some puppy NUTRICAL from the vet and pet store and give it some in the morning and at night. As far as the vaccines go, make sure they do not have the vaccine for Lepto in it. That is the one that causes the most adverse reactions. If they do have a reaction, their face will swell, and the throat can be closed off where they can't breathe, also they can break out with a rask all over the body.