Two days in a row a large dog has visited when I am not home and my dog is penned up. This large dog that I have not personally seen has spent considerable effort trying to get into on of my breeder pens. Evidence is in ground where it has been effectively plowed by dog pacing perimeter of pen and ripping off the rain cover. My neighbor thinks the dog is a bull mastiff but he does not know owner, nor do I. Tomorrow I have parental leave and will post myself out by front window and wait for dog's return. Dogs activity will be documented with camera before I engage it. Options presently on table are SSS, sub lethal shot with firearm (0.22 rifle or 410 bird shot), pain without serious injury shot with pepper spray or BB gun, putting my dog on to interloper and with me helping out with ax handle, capture and transport to human society shelter, or keeping the dog and breaking it in for use as a livestock guarding dog. My county does not have an Animal Control department. If identification is present then owner may be contacted. I spoke with county sheriffs deputy and he said poultry are livestock according to county and state code so killing dog while harassing my livestock is within my rights but that I will be potentially in civil court if owner comes forth to challenge any harm to dog. Officer suggested SSS and pepper spray options although latter will have dog associating me with unpleasantness and not simply the visit. Keeping dog for myself will be expensive because such a critter will have a major feed bill associated with it and possibly vet bills as well. Anybody want a bull mastiff?