This is a dangerous dog at this point. It is good that he is still giving a warning growl (at least part of the time) but having now bitten a person twice, he will have less & less bite inhibition. I would absolutely keep him away from your granddaughter. You might want to contact the rescue or shelter you got him from but realistically, a dog with 2 bites already on his record is not going to have good options. It sounds like the entire litter is not ‘wired right” in the temperament area.
You need to find a local trainer or behaviorist who is skilled & comfortable working with a reactive/aggressive dog. This is NOT something that can be handled over the internet or by the normal obedience trainer. I wish I could be more positive but I am concerned for you & your family.
