Pope Gregory IX declared in 1232 that domestic cats were diabolical, and the Holy Inquisition was almost as exercised about the danger of cats as it was about the threats posed by heretics, schismatics, secret Jews, and the Bible in vernacular languages. Between the 13th and the end of the 17th centuries, many (probably millions) of cats were executed in Catholic Europe, along with a considerable number of their owners, who were understood to be witches.
Sometimes dogs were also eliminated in periodic campaigns against animals thought to be associated with The Devil, a relationship the Church always charged against cats. To this day, dogs are also viewed as particularly haram (forbidden) in Islam, which has maintained a psychology much like that of Christianity in its Medieval golden age. Perhaps all obscurantist, authoritarian, repressive religions share this horror of domestic pets, creatures blithely and scandalously ignorant of the orders dictated by the Church or the Mosque.
In Europe and the Mediterranean, this attitude had an important historical consequence. The superstitious reduction in the cat and dog population naturally led to an increase in the rat population. The latter effect surely helped the rat-borne spread of Yersinia pestis (the bubonic plague bug) which decimated the population of humans in the European and Middle Eastern pandemics of the 14th through the 17th centuries. Dog and cat lovers will perhaps recognize in this history an old proverb: what goes around, comes around.--- Dr. Phage