Hope I ain't too late since I got over 20 miles of electric fence (livestock containment) the biggest problem is with the plastic insulators the wire makes contact and shorts out, I use a 50 mile box with 3 grounding rods which gives me 3 joules of zapping power throughout the fence and yes it hurts like the dickens when you inadvertly touch it. wrapping the wire around the ground rod is worthless use a clamp, keep grass off the wire, clean each contact point of fence wire with sandpaper, or like steve recommended shoot the dog. What I have set up works on over 100 goats, 3 dogs, 16 horses, along with trespassers and myself. good luck.