My puppy has white foam coming out of her mouth she's not gagging she just keeps shaking her head its 2am and I don't know what to do the vet is closed and noones on call when it happens she rubs her face on the floor and she looks so scared but when it passes she seems fine?

Foam can be upset stomach (she may have eaten something on the floor or in the garbage) or it can be serious, like distemper. What shots has she had, and did you let her be outside much before her shots? Will she drink water if you put a tiny dab of milk in it?