Abstract: A device to detect and signal the moment when a beast prepares to give birth. A container having fastening means for attachment on the behind of the beast is connected at its upper part to a tube extending so that its free end can be introduced into the vagina of the beast beyond the urethra. In the lower part of the container there emerges a tube of small diameter which is connected to a pressure sensor connected in the electrical circuit of an alarm device for producing an actuating signal for said alarm device in response to an increase of pressure in the container. In this way, an alarm is given as soon as from the breaking of the allantoic and amniotic sacs of the beast. The device further is arranged to monitor the subsequent development of the dropping.