Aggressive neighbors dog. Legal solutions?

My neighbors dog barks and attacks me whenever he is out. He nearly bit me today. I respectfully talked to my neighbors. But so far they do nothing, except for locking the dog. The next time their son lets him out my child or I will be bitten! This get very dangerous!

What legal options do you have at this point? – HOA? – if police department, what can I file? – any other city or government agencies? – any NGOs?

Do I have the legal right to defend myself from a dog? Knife? Firearm? What are the legal consequences? THANK YOU!