they did make a couple of incisions to get rid of the water, and FWIII comments that if they could have done that when he was still alive, he might not have died.
Wait, why is this? Did they think he died of the dropsy?
I think so, yes. Dropsy is repeatedly described as "fatal", and much of the treatment Fritz's doctors were recommending (which he blithely ignored) in his last year was aimed at bringing the water retention down via diuretics. Everyone noticed that people who got dropsy (FW! Wilhelmine! Fritz!) tended to die, but I imagine the connection to underlying organ failure wasn't really well understood.
Re: Various questions from Mildred
Wait, why is this? Did they think he died of the dropsy?
Re: Various questions from Mildred