In brief the law is:
1. A farmer commits a criminal offence in threatening to shoot a dog, and also in actually shooting a dog, unless he honestly believed his livestock was 'in immediate need of protection' and that ‘the means of protection adopted or proposed to be adopted were or would be reasonable having regard to all the circumstances’. So where shouting, throwing something or shooting over the head would be enough, then that is what should be done first to avoid committing an offence. (Criminal Damage Act 1971).
2. The dog owner can sue the farmer for compensation, and his only def