Trademark attorney can help you decide whether your mark is likely to be able to be registered, and what steps need to be taken in order for it to be protected. They will also advise you on how best to protect your mark from other parties who may seek to use similar or identical terms as yours.
General practitioners have no special training in trademark law or practice; they just sit in their offices all day long working on cases that come through the door. General practitioners are good at dealing with people who are having problems with their medical conditions (the kind of clients who might need help filing a lawsuit against an insurance company).