The key was heated and pressed onto the area where a person had been bitten by a dog suspected of having rabies. If done soon after the bite, the heat could
cauterise and sterilise the wound, potentially eradicating the rabies
virus. The practice was endorsed by the
Catholic Church (though rarely observed in
Orthodox regions), and priests used such keys at places associated with St. Hubert. There, the skin of both humans and animals was branded as protection against rabid dog bites. This practice was recorded in the 1870s in the
Ardennes region of France, where dogs were branded with St. Hubert's Key as "a sure preventative of madness". == Historical significance ==