Another question that could be asked is: "Father, is it true that in the Middle Ages the Catholic Church actually taught that there were evil dragons? And do you believe in dragons Father? Have you seen them? And If the Catholic Church believed in dragons then, but doesn't now, what other things did they preach that are no longer "operative?"
The answer to that question is no, it is not. Firebreathing, flying dragons were a popular folk superstition in the Middle Ages, but the Church never taught that such beasts exist.
The LXX text of the Book of Daniel makes mention of a dragon, but this is a generic term for an enormous snake, not a flying, firebreathing beast. The Book of Daniel does not describe any of the magical qualities ascribed to dragons in European folklore, it is just a very big, vicious snake living in a Babylonian temple. In Latin and Greek the words "draco" and "drakon" usually Englished as "dragon" were actually used by the Romans and the Greeks to refer to pythons. There were no pythons in Europe so for the uneducated European peasant of the VIIIth century a "draco" was clearly an enormous and frightening beast, but he had no mental picture of what it actually was. So folktales came up with a more and more elaborate picture of what a "draco" might be.
And If the Catholic Church believed in dragons then, but doesn't now, what other things did they preach that are no longer "operative?"
The Catholic Church never "believed in firebreathing dragons" any more than the Catholic Church "believed cats have nine lives" or the Catholic Church "believed that if a ring suspended over a woman's belly rotates in a circle she will have a girl."
Old wives' tales have nothing to do with Church teaching. It's like saying that "In the 1920s the Catholic Church taught that cigarettes are not harmful" simply because the vast majority of Catholics in the 1920s sisn't think that cigarettes were bad for you. The Church never said such a thing, let alone taught or asserted such a thing, but by your logic, it did, somehow.