We just got back from the vet. One of our newborn rabbits got her paw tangled in the bedding. We were using the store-bought cotton nesting material, which I would certainly not recommend. Unfortunately, we did not catch it in time, and the paw was deprived of blood for too long. Much of the paw did recover, but the toes did not.
The odds of surviving the amputation were not good. Even in adult rabbits, the survival rate is low. In a week-old such as this, there was nearly no chance she would survive it. If left untreated, it would spread and eventually kill her.
She was euthanized about an hour ago.
The other four are doing exceptionally well, and we expect them to open their eyes by the end of the weekend. We're using a couple old t-shirts for a nest now, which they and the mother are satisfied with. We're hopeful they will make it through.