Just keep in mind the old saying........what goes around comes around. I'm sure you've heard that a million times already though. It is even a bit difficult to get help with animal abuse issues near the city. It's so wonderful to know that there are other people in this world who will not give up punishing the evil people who do things like this. I think you are right when you describe him as a sociopath. And these types of people should be given absolutely no mercy. I bet he is one of those evils souls with no purpose of his own in this world. You seem like you are right on this, but don't let him wear you down. I'm sure that's how they operate......like parasites. I will definitely let you know if I come up with any good resources, ideas, etc. I'll also see if I can find anything on healing dogs who've been poisoned with antifreeze. This might be a little out there, but have you ever heard of Essiac Tea? It's supposed to be a cancer fighter, just about all purpose cure for almost everything. Look it up on the internet. Also can be called Ojibwa Tea. My cat was very sick with a respiratory virus, and I mixed it in her soft food for about a month. She is back to normal completely. I have more stories too about it, but I'll go on only if you want to know more.
I will pray for your dogs, and for this "man" to receive just what is coming to him.