Okay, I'm confused as to what the problem is here. 
This dog is clearly a menace, (most likely due to poor owner care) but a menace, nonetheless. WHY is nothing being done? 
In my area, if a dog is a problem, it is put down. The owners are liable for damage.  
It seems to me that there MUST be something else that can be done. Has the media been alerted? Get them on your side. Absolutely find another attorney, if the one you have isn't going to get you more than $50. Your son's (and his dog's) medical bills should be covered AT THE VERY LEAST. I'm with a previous poster. You son may very well suffer from PTSD in the future. That needs to be accounted for, as well. 
I could go on and on, but this injustice seems WAY over the top here.     
				__________________  Cricket   and   Zaccheus' human     |