Documentary, Science and Nature Documentaries - Astonishing visual effects take viewers inside the wombs of pregnant cats and dogs in this remarkable National Geographic series about the miracle of life, the trials of birth and the milestones of fetal development. The cats segment compares the in-utero progress of a house cat to that of two breeds of jungle cats, while the dogs portion charts the development of three domesticated canines and their ancestral cousin, the gray wolf.