My dog has dug many holes in my back yard what can I do to fix it.

Hello. My puppy did the same thing. I would take her to the hole and tell her no, and would also catch her and tell her no. Keep on your dog and they will stop. I went around and filled the holes with top soil and then replanted grass sprinkling seeds on the topsoil.

https://www.wikihow.pet/Stop-a-Dog-from-Digging

All. I can say is good luck. With an electronic training collar, you can give them a tonal warning, but you have to catch them in the act. I advanced to vibration.... But unless you catch them everytime, it is difficult to break

Your dog is probably bored. Give it something else to keep it's attention focused on.

Fix what(it)? The dog or the holes. HaHa

Sounds crazy but works. When you fill the holes bury some of his poop in it. Agree your dog is bored. Long walks a few times a day will tire him out, and play ball with him. If you don't have the time, hire a professional to treadmill train him. Many benefits to it.

Make his/her own little area where they can dig all they want.

I go to Habitat for Humanity and buy old oven racks for $2 ea. Scoop up some poop and cover it with dirt. Lay the rack over the top and plant some grass seed.