@cristian1980 Honestly IMO very young kids should never be in a dogs’ space like this. Kids are weird to a dog and move quickly and unpredictably and sometimes even very friendly dogs can be put off by young kids. Add to this the fact that young kids cannot read dog body language and you have a recipe for disaster. If you keep the dog he and your son should not be interacting freely until your son is older. Even then they should not be unsupervised.
Your dog was expressing that he is uncomfortable with what happened. He may have shown more subtle signs that were missed (facial expression, body tension, displacement behaviors, etc). I can’t tell you just from this post if this is a dog that will be okay around kids in general, but a warning growl/snap with no contact says to me this was a warning to say “hey I don’t like this”, not necessarily aggression. He’s telling you he is out of his comfort zone.
Do some research on dog body language and observe him closely when your son is around (absolutely do not let the baby close enough where a snap is a possibility). Many dog behaviors that come across to us as friendly and happy can actually be displacement or appeasement behaviors from a dog who is anxious or unsure. Book a consult with a behaviorist if you’re able (like an actual behaviorist not a trainer). They will be best able to asses your individual situation and tell you what your options are.
Kinda side-eyeing a lot of the comments here suggesting BE for this dog. I am a huge proponent of BE in a lot of situations but this isn’t one of them unless there’s more going on than the post indicates. Dogs are allowed to have boundaries. He may not end up being a good fit for your home or a home with young children (many dogs aren’t) but a single snap with no contact is not BE material.