This is the moment when a furious father stabs a pit bull to death in revenge for a savage attack on his 12-year-old son.

The dog’s victim – named only as Lionel in reports – was knocked to the ground as he walked with two friends in Caleta Olivia, Argentina, on 30th December.

As the pit bull sank its teeth into his neck, a passerby saved the boy from worse injuries and took him home.

CCTV footage recorded later outside the owners’ home shows the father’s furious attack on the dog.

As the pit bull attacks him, Oscar Alberto Ernalz stabs it 10 times with a knife until it falls in a heap on the ground.

Then he slams the knife down into the dog’s side one more time to finish it off.

Earlier, reported local media, the father had been angrily quizzing the dog’s owners.

But as they denied owning a dog, the pit bull ran out and began chasing him.

Ernalz told local media: “I told them they had to put this dog down because if they didn’t, I would.”

He explained: “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.

“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.”