Dogs do not eat food, just drink water, and vomit. What medicine can be taken to be human?

Both have been three days. They do n’t eat food, vomit, and have no spirit. They are all thin. At first, they do n’t eat. Now they only drink water and vomit out after drinking. What happened? I don’t eat food for a few days, can I die, what kind of medicine should I take? Can make it better