I think you're right, sounds like it might be spinda bifida. I'm surprised that I haven't heard more rabbit breeders having this problem. I wonder if it's really rare. What do you think, should I breed her again? Since two kits were affected, it makes me think the next litter will suffer from...
We recently got a NZ buck and two Cali does (mom and daughter). Mom had 7 healthy babies two months ago. Her daughter didn't take the first time, after rebreeding she also had 7 babies. I took each of them out of the nest after a few days and noticed that two had issues with their hind ends...