he shouldn't of brought that dog on our property
I think that's exactly right. If the neighbor's dog can't behave, the fool who owns him should know better and control the dog (leash) or leave him at home.
If you kill that dog, (and it probably deserves it) you may start a warthat could put your own dog's in jeopardy.
Talk to the neighbor about your bills. If he doesn't quickly make right financially - sue. You've got to be a lock (unless you retalliate) for damages, pain and suffering, court costs, etc.
(for the record - I don't think I would have been able to write on this forum tonight if my two dogs were injured because I would have been wearing police issue bracelets after I beat the tar out of the guy.)