We also try to give him exercise by going on long walks when the weather permits. I'm looking for some safe home remedies to completely stop my 2 year old male neutered black Labrador Retriever dog from digging up my backyard. I look forward to hearing your suggestions. Put charcoal in the hole. Then try refilling the holes with junk.
Dogs quickly lose interest and pretty much stop digging.
Fill the hole with whatever is at hand - dead leaves, sticks, pine needles, rocks or even dog feces. Fill the top 2 inches or so with dirt. The dog finds the stuff, gets discouraged and often quits digging. They seem to get the idea they'll never know where they'll find junk, and it's not worth the effort to dig only to find junk so they quit. The Koehler dog method advocates filling holes with water and sticking dog's head under the water for a few seconds or so.