Think like a Berkshire at fence height
A Berkshire does his escaping at ground level. This is a heavy, muscular pig with a strong neck and a habit of rooting that turns soil along a fence line into a shallow trench over weeks, until one evening his snout finds a gap under wire that looked flush a month ago. He also leans and rubs, working a post or rail with his shoulder in the same spot until fixings loosen. A useful inspection therefore happens at knee height and below, not from standing eye level, and it tests the fence the way he does: steady outward pressure, attention to the bottom edge, and suspicion of every corner where two runs of fencing meet and neither is anchored as well as the middle.
Walk the bottom edge and look for rooting work
Walk inside the pen first so you see the side he works on, crouching at intervals to sight along the bottom wire or board and spot daylight underneath. Probe rooted areas with a boot toe: if soil crumbles away and the gap grows, he has already done half the digging, and that stretch needs the bottom line pinned down, buried, or backed with a solid board rather than simply refilled, since loose fill is an invitation to dig again. Check where water collects, because a Berkshire will wallow and root in softened mud right against the fence, undermining posts faster there than anywhere else in the pen. Pull grass and weeds away from the line as you go so hidden rust, broken wire ends, and a snapped lower rail are not left disguised until he finds them.
Test each post by pushing hard at its base and again at pig shoulder height. A post that rocks in softened ground may still hold a person back, but a Berkshire leaning his full weight repeatedly will walk it looser each day, so note rocking posts for resetting rather than trusting them. Run a hand along wire joins and staples, replacing any that lift, and confirm panels overlap at corners with no vertical gap wide enough for a snout to enter and pry.
Give gates and latches a pig-proof test
Close each gate and then push, lift, and rattle it the way an impatient pig does when feed is late. Many pig escapes happen at gates that swing correctly for people but lift slightly on worn hinges, opening a wedge underneath that a snout widens in minutes. Check that the latch cannot be nudged upward by a nose from inside, add a second low fixing if the gate flexes, and confirm the gap under the closed gate matches the fence bottom elsewhere rather than becoming the lowest, weakest point in the whole circuit. Look at the ground just inside the gate for fresh rooting, since pigs concentrate effort where they see people and feed arrive, and move feeding away from the gate line if that patch is always churned.
Recheck on a rhythm and prepare for the day it fails
Repeat the full circuit after heavy rain, after moving the pig to fresh ground, and whenever you notice new rooting along a stretch, because Berkshire fencing fails gradually and then all at once. Keep a simple note of which post or corner needed work each time, as repeat trouble in one place points to a design fix worth doing once rather than weekly patching. If he does defeat a repaired line and reaches the lane, his listing on KinsLe under the Lost Pet Alert System helps local households recognise him and helps the person who pens him in a garden get in touch with his owner.