10 month old son was licked on mouth by dog. no bites or scratches. later tonight he threw up. im worried he will get a disease from this. when will symptoms show up/ am i worried for nothing?

Unlikely a problem: The lack of any bite/scratch makes this less of an issue. Human saliva has properties that suppress bacteria. Viral transfer is possible but unlikely to matter. Kids that age test their system hundreds of times daily when their fingers enter their mouth. I would consider this a minor exposure & monitor him as you always do.