Abstract: A collar-mounted electronic apparatus (1) for control of barking by a dog includes a housing (2) supported by a collar for attachment to the dog's neck, first and second stimulus probes (5) connected to a surface (9) of the housing, a vibration sensor (6) supported by the housing for detecting vibrations caused by barking by the dog and control circuitry in the housing having an input coupled to an output of the vibration sensor. The control circuitry includes output terminals producing aversive stimulus signals in response to barking by the dog. A counter included in the control circuitry is incremented in conjunction with each occurrence of an episode of aversive stimulus applied to the dog in response to barking by the dog.