A dog eating it's own poop is disgusting to us humans but actually the poop that the dog is eating is beneficial to the dogs health and digestion.
But if you prefer the dog not eat it's own poop you can add some lemon juice, hot sauce or meat tenderizer to the dogs food.
The meat tenderizer added to the dogs food will cause the dogs poop to taste very bad and the dog will not want to eat it.
You can also add a few tablespoons of canned pumpkin to the dogs food and the poop will also taste worse as a result and the dog will not want to eat the poop.
Also when you notice poop in your yard or when your dog poops you should immediately pick the dog poop up and dispose of it.
Picking the dog poop up will keep your yard clean and prevent you or someone from stepping in it and will prevent the dog from eating it.
Still there's no harm if your dog does eat some of it's poop because it's very natural even though it's gross to us and I would also prefer my own dog not to eat it's own poop especially because it licks me on the face sometimes.