Actually, it's worse than that - all the dog has to do is go in the same enclosure as the livestock, off-leash, whether it's causing distress or not :smt107 !

I had occasion to check this with the police once, when a neighbour (now dead) threatened to take my dog away and shoot him (for something he had NOT done).

The dog has to be shot in the act, however - it cannot be done afterwards without Court action.

Snorri