Abstract: This invention relates to apparatus for monitoring the pulse rate of a human or animal subject, including a pulse detector for attachment to the subject which produces a pulse signal corresponding to the pulse of the subject, a transmitter which transmits the pulse signal to a remote signal analyzer and indicator which exhibits a characteristic of the pulse. The indicator may be a monitor to continuously display the pulse rate or an alarm which indicates an increase in pulse rate. The invention also provides a method of detecting pain by detecting an increase in pulse rate using the apparatus. The invention also relates to a new pulse detection method for an animal for attachment to the underside of the tail of the animal.