How old do dogs know when they are hungry and full?

Dogs have the concept of hunger and fullness since they are born. When puppies are hungry, they will pursue the smell of the mother dog’s nipples and suck the milk on their own. When the dog is full, it will stop on its own. Dogs will not stretch themselves to death. Although dogs are not as intelligent as humans, they still know how to be hungry and full, and rule out the possibility of bulimia. Dogs will generally stop eating after they are full.