To treat this and other problems in the rabbitry the best solution is to consult with your Veterinarian. I give them Oxytocin, a synthetic hormone, which causes the uterus to contract and help the Doe to deliver the Kits. In most cases this is all that is needed to help the Doe to deliver the Kits, if this does not help then a Vet should be consulted. Strict culling is needed to prevent this form happening in the future. This is usually a hereditary trait that can be bred out of the bloodline.
Nest boxes can get dirty fast, from either the Doe fouling it or from the afterbirth.
This is a big problem and must be controlled to ensure the health of the Kits. There is new stress added to the Fryers caused by leaving the Doe. To help prevent these conditions the producer must use preventative measures such as electrolytes in the water. If antibiotics are to be used then a pro-biotic is suggested to replace the good bacteria in the Fryers stomach. Without the good bacteria the Fryers can not digest their food properly and will die anyway.