UPDATE
Well, things are not going as well as I would have hoped. I was taking Stewart aka Cujo (as Karen calls him) out of the car the other day as some school children were walking home in front of our house. Stewie tried to go after them, barking and snarling. Usually we go from car to house and back without a lead but for some reason I had snapped one on him that time THANK GOODNESS and was able to hold him back.
At the dog park, all his undesirable behaviors have intensified and I just can't take him anymore even with the muzzle unless it's very early in the morning and I confine him to a smaller, enclosed side area. If someone else also wants to use it I have to remove Stew.
We have escalated his care now to a behavioral veterinarian who can prescribe medication if she thinks that will help. We don't know what approach she'll take but we hope it's multi-dimensional because relying solely on psychotropic meds to keep the children of our neighborhood safe isn't something we want to do. We don't know anything about this so we'll of course wait to talk to her (on 2/7) to make a decision. We got her name from three separate sources (our vet, Stew's trainer, and a friend) so this seems the right direction to go.
Sigh.