Yes, I have a girl righ now who has recovered from Distemper (and she was fully UTD on all her vaccinations, too.) Also, waaaaay back in my youth, I watched my mom nurse two seperate dogs through distemper (several years apart from each other).
The most important thing we were told is to get nourishment in them any way you can. The vet said to feed the dogs whatever they'll eat (within reason, of course). My mom fed both the dogs Kentucky Fried Chicken for two to three weeks (it's the only thing either dog would eat). When my girl came down with it, I fed her a Boiled Hamburger Meat/Rice mixture, along with some pedialite (seperate, not with the meat/rice mixture), every few hours. Although she recovered, she does have some problems as a result of the disease (as distemper is a neurological disease affecting the brain and nervous system). She is a happy girl now, and healthy (all things considered).
I hope Zeus makes a full recovery. Get him to eat something. Anything. Start out with just very small amounts. Small amounts of water (or pedialite, or Gatoraid) and small amounts of whatever he'll eat. He's not dehydrated, is he? If he's dehydrated that could be one reason why he can't keep water down (sounds odd, I know, but there comes a point when the body is so dehydrated that it can't keep water down even though it's despirately needed). If you pull up the scruff of his neck, and let it go, does it stay up or does it snap back into place? If it stays up, or is slow to get back into place that is an indication of dehydration. SubQ fluids may be required....
My thoughts are with you.