is the dog are going to be executed or not for mauling the child is a tough question. If animals attacked human it is logical for the victim or other human to do self defence or defence the other, that mean if I walk pass the street and I see a kid mauled by Pitbull, if I pick up the stick and hit that dogs in the head that might can kill the Pitbull in order to save the kid, this action is not only permissible but morally recommended.
However if the Kid mauled by the Dog, and after the incident you want to find out the culprit. Using moral reasoning you hardly blame the dog because they are animals, they don't consider what they do as a mistake, it is part of their nature, the only one who can be blame for this incident is the man who own the dog, because he is the only person who able to bear responsibility for what the dog did.
But we already did this for centuries, the animals that harm human must die, and deep in our heart we not do that to anticipate other child or other peoples to get harm in the future but we did that to establish justice, to give the sense that the culprit was punish, and justice is prevail. But in this case if one not execute the dogs it may end up no one will get executed, it mean the sense that justice being establish will absence. Killing the dog might not bring back the kids eye, but not punishing anyone or anything to what happen to this child might surely grieve both of the kids and family, as it turn the table completely that the kid actually not a victim of this incident, even though it might be not truth but the family or the kid might find or feel it that way, and no one is wrong for the harm that is suffered by this kid. For those who symphatize to the dog just think what if this kid is your own son, so you might able to see this case in various side.
The only reasonable answer is to form a law regarding pet owner especially those who have special pets like again Doberman, Pitbull, and other kind of Pet including exotic Pets like Fox, Snake, or others, without this the dog will likely to be punished to satisfy the victim, to give the sense that justice is been apply. Sound awful.