Let me start this by saying, I have electric fencing as a deterrent with my horses to keep off my fencing, but never put a lot of faith in it to keep predators out. Here are a few reasons why and one happened yesterday. Four months ago, my neighbors goats were attacked by two dogs that had run away from another neighbors home. They were missing for two weeks. When they found their way back to familiar territory, they attacked the goats, both behind serious electric fencing. One of the goats had to be put down. The victims owners showed compassion for the dogs since they were skin & bones and tick infested when they returned. No doubt starving. The fence was reinforced with from five to six strands of hot wire and an even more powerful unit to charge the fencing. This fence has gotten me on two occasions. Once from touching and once from being four inches from it and it arched. Both times, it took me to my knees. This fencing is no joke. A miniature pony, about 300 lbs. was brought home to keep the remaining goat company. Yesterday, the neighbor came home to find his own three large dogs had dug out from under their fencing and attacking the mini. The goat was ramming the dogs trying to help her pasture mate. It was clearly evident to the owner that the fence had gotten the dogs because they were afraid to go back through it when he charged them with a tree limb to get them off of her. They wanted out, but didnt want to get near the wire. To make a long and grueling story short, the damage was so severe to her hind end, a wound the size of a basketball where theyd actually gotten to her intestines, that she had to be put to sleep. The only fencing Ive ever seen that keeps wandering dogs or coyotes out of a pasture is the 4x2 welded wire with a charged line at the top. Im not saying a fox cant jump it, Ive seen that. However, if the dog wants in, hes going to have to spend some serious time digging, which most passing through will not do. The dogs in question above, had nothing but time to dig out of their own pen. Whats disturbing is that they are well fed, sweet dogs. I know you cant bred the true predator out of them, but this was clearing just a joy attack for them. Needless to say, they will not be around much longer since theyve gotten a taste of blood. My friends dont want any other animals deaths on their hands due to their own dogs.