Animal Instinct and Child Birth

What, then, is the difference between human and other animals? Are their bodies made differently? As a matter of fact they are remarkably similar. Cat and dog bodies are used in premedical anatomy studies due to the similarity of structures with identical name and function. Is it that they just can't experience pain? Following a natural-childbirth newspaper article, an indignant letter to the editor asserted cats can have kittens without pain because they cannot feel pain as human beings do...