Bronchitis in infants?

My son is 2months old and just found out he has bronchitis .. He still hardly eats He said it would take a day or 2 for him to finally go back to normal eatings.. is this common did your child hardly eat when they had bronchitis.. I just worry about dehydration we do try to give him the petialyte.. when he wants it. what else can i do to kind of help him