I have had 2 goats get deathly ill with a couple of weeks of giving birth. They lose weight and get the runs then they're down one has died and the other not far behind. I have several other goats getting ready to kid. I need to figure out how to stop this from happening in the future.

Don't you have a large-animal vet? Ask him to diagnose the problem.

Is this before birth or just after? Are they lethargic? It sounds like ketosis or milk fever I suggest calling your vet.