dog bite

Question
What should I do with my 15 mth old lab who just bit my son.

Answer
Get good professional in-person advice as soon as possible. And keep the dog away from your son until then. There is not enough information here to give advice (about the situation, the age of the child, what was going on at the time, the location and severity of the bite etc.) but even with more information, dogs who bite children are a subject for in-person professional help, not internet advice. There are simply too many variables, too much chance for misunderstanding, being unable to see what is going on, and nobody wants a child injured.