It is a strictly human disease. Did the Good Lord bestow the gift of gonorrhea on Adam, or was it Eve? Who carried it onto the Ark? Why would God instruct Noah to carry any disease organisms or parasites onto the Ark? One of Noah's family had to have been infected, but they were the only people worthy enough to be saved on the whole Earth. Which one had the clap? Why would He create anything so nasty anyway?
Well isn't that an nasty little problem. You can read many other niggling little issues with The Flood story here. Of course, the whole thing could be explained away by allowing that the Noah story was a
rip-off amalgamation of many near east flood stories. But that raises nasty questions about the origins of Christianity.
Nah, it's just easier to dismiss all that troublesome history by claiming Christianity really existed before it ever came into being.