Seriously, why don’t you just block any gaps so they can’t come through?
Because I have hedge, stone wall, barbed wire fence and wooden fence and to sure up if that’s the case. It’s not practical.
I didn’t mention in the op but the man who lives there doesn’t technically own the dog. The lady who lives with him bought the house with her ex husband, and shortly after they moved out to the country their marriage hit the rocks. From what I can gather they were both paramedics and they seemed to use drink to cope with the stress of the job. Anyway the dog is apparently owned by either her ex husband who no longer lives there, or her adult son who no longer lives there. Both are apparently nasty pieces of work.
I’m not intimidated in the slightest by that but I’m also somewhat wary of maybe getting into any kind of acrimony which might lead to violence. I’d rather hit the dog in the arse with a ball bearing than strangle the owner.
Anyway thanks for all the suggestions, paint ball gun and even more likely catapult would seem to be the order of the day. Might mess around with catapulting paintballs filled with chilli sauce or something similar.