We have Underground electric fencing for our dogs (Invisible Fence) and for our first seven dogs it worked great. Our eighth dog, a shelter mutt, decided that killing our chickens was more important that getting zapped by the strongest collar possible. We added a Ft. Knox physical fence, with electric tape on top, and the IF three feet inside of the 'wall', and it worked great.
Until, years later, the 'motherboard' died, we didn't know it, and another rescue dog dug out and killed many of our chickens, in about an hour, one very sad day. Everything was fixed, and all has been fine since. Our job as owners is to keep our critters contained!
Many/ most dogs will respect a good underground system, but not all.
Mary