A detecting arrangement is provided for a teat cleaning device including a teat cleaning cup in which teats of milking animals are contained during cleaning thereof. The detecting arrangement comprises a measuring device provided for automatically measuring a teat related parameter in or adjacent to the teat cleaning cup at completion of a teat cleaning process, and a processing device operatively connected to the measuring device and provided for automatically comparing the measured teat related parameter with a reference value and for automatically determining whether the teat of the milking animal has been contained in the teat cleaning cup unfolded during the teat cleaning process based on the comparison.