✔ 最佳答案
You won't need a pen if you dog proof your yard.
dig a trench out from the fence about 2 ft wide & about 6 to 8 inches deep. lay in some 2 ft chicken wire & attach it to the chain link every foot. Then bury the wire. No more digging out. I did this around my little half acre. & that is the same thing the local Wolf Rescues do their pens & some of their pens are 1/2 to 5 acres.