Background he's a 3 year old border collie. He's a gorgeous and can be very affectionate but he has gone at me aggressively 2x now. Once when he was a pup and trying to dig under the gate I kindly (not aggressively) directed him and he attacked me. I know puppy teeth but he lacerated my arm. Got a tetanus shot and thought that ok it's not normal but he's a covid puppy so probably not been socialised. He really went for me again a few weeks ago (bared teeth/ low growling/ snapping at me) I'm scared of him
Had a party at the weekend and loads of dogs were in our garden he turned up and went full on aggression. He attacked other dogs and bit someone who was holding his lead and trying to hold him back
He's terrified of loud noises/ will hide from kios
Would it be kinder to let him go... he's not my dog and his owners are trying for a baby.