CCTV footage caught the dramatic moment the dog was killed
The young boy, Lionel, was knocked over by the dog while on a walk with two friends in Cale Oliva, in the southeast of Argentina, on December 30, 2022.
It then viciously attacked the boy and sank its teeth into his neck.
A passer-by spotted the attack and managed to narrowly save the 12-year-old from certain death.
His father then took matters into his own hands, with CCTV footage recorded outside the owners' home showing the dramatic moment the dad killed the dog.
Oscar Alberto Ernalz stabbed the dog 10 times with a knife until it fell in a heap on the ground, finally slitting the dog down its side to finish it off.
Local media had earlier reported how the father had been berating the dog's owners for allowing it to roam outside without a lead.
It is thought the owners initially denied owning a dog, however it then ran out of the house towards Ernalz.
It was at this point that he decided to enact revenge for the attack on his son.
Ernalz told local media: "I told them they had to put this dog down because if they didn't, I would.
"As soon as I turned around, the dog jumped at me and didn't stop attacking me. To put it coldly, it made my job easy."
Ernalz said that he felt his actions were more than justified, given how close the dog came to killing his son.
"My decision and that of any parent would have been the same.
"You have to be a coward to play dumb and follow the legal process that doesn't amount to anything."
He added: "It was a miracle to have my son there, because no one ends well after a pit bull attack."
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