A dog who digs out under a fence is rarely digging at random. He digs at the spot where the soil is softest, the view through is best, or something on the other side — a passing dog, a cat's route, the front path — rewards the effort. Filling the hole alone never works, because you have simply prepared loose, easy soil for his next attempt. The fix has to make the fence line itself undiggable, while the rest of his day makes escape less worth attempting.
Make the base of the fence solid
The reliable solutions all put something unmovable where his paws expect soil. Paving slabs or a row of large stones laid tight along the inside base of the fence work well and are quick to check. For a dog who digs deeper, dig a shallow trench along the fence line, lay wire mesh flat in it or angled outward underground like a buried skirt, pin it, and cover it back over — he digs down, meets mesh, and cannot tunnel forward. Where he is escaping under a gate, a concrete strip or a threshold slab beneath the gate closes the gap he uses. Work along the whole run he has access to, not only today's hole: a blocked digger simply moves three metres sideways and starts on fresh ground beside your repair.
Deal with the holes he has already made
When you fill an existing hole, make it a place he does not want to reopen: many owners bury the dog's own waste just under the surface of the filled hole, which puts most dogs off digging there again, or pack the hole with rubble and bricks before topping it with soil. Then compact and cover it as part of the solid barrier work above. Watch him on his first garden visits after the repair — where he sniffs and paws tells you where he is planning to try next, and catching a new scrape early, while it is still a scrape, is far easier than rebuilding after a second escape. If he is getting out to reach something specific — a neighbouring dog, for instance — talk to the neighbour about blocking sight lines or access on their side too.
Give digging somewhere legal to happen
Some dogs dig out because the garden is boring and the world beyond the fence is not; others dig because digging is the joy itself, especially terrier breeds bred for it. For the digger-by-nature, build him a digging pit: a sandpit or a loose-soiled corner where you bury toys and treats for him to excavate, and praise him for using it. For the bored escape artist, the answer is upstream of the fence — more exercise before garden time, company out there with him, and not being left alone in the garden for long stretches. A tired dog with his people around digs at his pit; a restless dog left alone for hours works on your boundary.
Check the line daily until the habit dies
Habits fade when they stop paying, but only if every attempt meets the barrier, which means spotting fresh scrapes and lifted mesh before they become a tunnel. For the first few weeks, walk the fence line once a day: look for new soil piles, paw marks at the base, or a slab shifted by persistent work. It is a two-minute job that is easily forgotten when it belongs to everyone in general, so give it to a named person each day. KinsLe's Care Teams makes that simple — the fence check can be set as a care duty for your dog and marked complete with a timestamp, so the whole household can see it was actually done.