:The system in Germany is different; neither MD nor PhD exist there, and any confusion is likely a result of different ways of translating from the German system. Technically it is possible in Germany to become a physician without obtaining the right to be called "doctor"; I know several such cases including my last German GP. Almost all physicians obtain a doctorate (Dr. med.), though. (Otherwise the patients are confused.) To do so, they must do a certain amount of nominal research. You can either translate this system as physician = MD, Dr. med. = PhD, or as physician = nothing, Dr. med. = MD. Neither translation is completely correct. Since de call him "Dr. Rath" he almost certainly has the degree of Dr. med., which I guess is slightly more than MD and considerably less than a PhD, although it plays a superficially similar role in the German system. Alternatively he could be a physician who obtained a proper research degree (Dr. rer. nat.), but a Google search suggests that that isn't the case. 
 :Short answer, he is neither MD or PhD, but Dr. med., which is the normal degree for a German physician.