We have a completely out of control RSPCA here in Australia, too. An RSPCA employee inspected my sister's horses, noted that one was underweight (it was a rescue she had had for four weeks and was rehabilitating with the assistance of a veterinarian) and shot it within five minutes of leaving her a voicemail. She was too distraught to take action but that man should have been fired and probably prosecuted himself.
Our RSPCA has three functions as an advocacy body, retail entity and investigatory authority. The latter is an appalling conflict of interest with each of the former two.