What symptoms have you noticed with the kits dying? They aren't dying just to die. There is something going on. At that age I would think mucoid enteritis could be the reason they are dying.
Symptoms of enteritis include: Anorexia, listlessness, bloating, weight loss, increased water consumption, teeth grinding, and diarrhea.
What are they being fed? They should be on mother's milk, hay, and pellets, but the mother's milk should still be the main part of their diet. Has her diet changed any?
Emily