Just one that I am concerned about. I have 4 dogs and 3 are good but one is a rescue who is very headstrong. We got him a few years ago and he still bolts off the property barking and running amok in the forest. If we had a farmer next door he'd be shot by now for sure. It's not all the time, but before we got him he must have been completely wild because he is the most challenging dog we've ever had. He's overly dominant, food aggressive and runs off.
We have fencing for either pasture or the perimiter around about 1/3 of the property and he won't go through it, but at the back there are forest and swampy areas and we get coyote, deer and who knows what else through at night. He is part hound and gets his nose on a scent and zoom! We have quite a bit of experience with dogs and he REALLY respects the electric farm fences so I think a dog collar / fence combo would be an excellent training aid. I don't care if he's not perfect, but if one of the farms near me had a problem with him running a horse or cattle or whatever I'd feel terribly irresponsible.
He's about 100 lbs, part hound and possibly great dane or maybe just a heinz 57 mix. Long gangly legs and he's freindly with animals otherwise, even chickens and kittens.
NOTE: I was actually going to run this above ground in some areas by running it along an existing fence.