What is the best thing to do if I believe the other parent is alienating my child from me?

Educate yourself. If alienation is present, your approach should be very different than ‘normal’ co-parenting situations. Besides reading materials by qualified psychologists, you will benefit from a consultation with a family law attorney specializing in parental alienation cases. Before retaining an attorney, ask him or her how many trials they have conducted changing custody regarding an alienated child; ask the attorney if they have a network of experts who can testify at trial and can provide counseling services.