First let me say that I'm so glad your son is okay!
Wow, do I feel your pain!!!! I too am an avid animal lover.
Our dog Gus bit my youngest daughter who was 1 yrs. old. I was in the kitchen cooking dinner and I heard Gus snap and then my daughter cry. He bit her on the face above the eye. She had 3 punctures. There was quite a bit of blood and I first thought he had gotten her eye. Thank goodness not!
We still have Gus. He doesn't have have any history of biting/nipping others. He has always been very loving, very affectionate, etc. He would play with my kids and let them love on him.
I'm not sure if my daughter hit him or what but something made him snap where he felt threatened. Don't get me wrong, I don't condone what he did to my child. My children's welfare comes before Gus.
After he bit my daughter he became an outside dog. We only let him in right before we go to bed and he's back outside before our kids get up.
My husband and I couldn't bear to give him to the animal shelter because we knew that he would be put down. Even though Gus doesn't have a history of biting/nipping, it was still a very difficult decision for us.
If your dog has a history of biting/nipping at people, adopting him out might be the best option for you. However, only you and your husband will know what's right for your household. Good luck! It's a very tough thing to go through.