I'm not in any way a legal expert, but while I agree you should say there's no monetary value, too, I don't think he could take your dog. I might be wrong, because I know pets are seen as property in the law, but I'm not sure that could be done, even if you owe money. It's highly unlikely, since your dog is a special needs case, so try not to worry too much.

I also agree that was unprofessional of the lawyer, and next time, tell him it's none of his business.