The invention concerns a device and method for detecting and indicating the preparatory phase of birthing a bovine or equine animal, that can be secured to the tail of said bovine or equine animal. According to the invention, such a detection and indication device comprises: -means for measuring the components of acceleration of said device according to at least one axis, and preferably according to three orthogonal axes -means for processing the measurements of said components, intended to detect an occurrence of said preparatory phase -means for generating a radio communication signal configured so as to generate said signal in case said occurrence is detected -means for transmitting said generated signal to a collector forming a relay or to a terminal.