A good way to get a dog to stop eating everything is to firmly tell the dog no when you see them trying to eat something they shouldn't.
You should work on drop it, leave it, and exchange games. Both “drop it” and “leave it” are great skills for all dogs to know.
A dog that wants to eat everything may have Pica which is a desire to eat non food items.
Pica in a dog is the consumption of non-food substances.
The most common form of Pica in dogs is the eating of the dogs own feces.
Dogs with Pica will usually eat their own feces as well as dirt, rocks and much more.
The feces is usually not harmful for the dog to eat if it's their own feces and can actually benefit the dogs digestive health.
But it's best to prevent the dog from eating their own feces when possible as it's really gross.
The actual technical term for a dog eating their own feces is Coprophagy although it's a form of Pica.
The condition of both coprophagia and pica in can cause problems for pets, and sometimes are the result of an underlying medical condition.
Pica in dogs is a condition where the dog feels compelled to eat objects that are not food items.
These non food items that the dog with Pica may eat can include metal, plastic, cloth, garbage, dirt, rocks.