No offense, but you never say WHERE you are from.
What does "insurance" have to do with owning a dog? Do you mean license?
I'd call the animal control officer, then the cities mayor or county attorney to find out what legal angle (statute and law) they are using to hold your dog. Then tell them you will get a lawyer to fight them, or sue them if they kill your dog. That might buy you some time.
I watch animal planet all the time and I just don't think they can TAKE your dog from your property because it was running loose unless they feel it was a danger to others, or you aren't caring for it properly.
Frankly, if your dog has been deemed a nuissance or danger because you are a moron and can't take care of your dog and provide it secure housing, then that is indeed a very sad story. They impound cars from people who don't pay their tickets, too. I never feel sorry for those people for some reason...
I truly hope the ending is a happy one for the dog's sake.
Candidly, I would have your son stick with a public defender at this point.
The fact that his friend got out earlier had nothing to do with who the defense attorney was. Your son is being accused of armed robbery. The friend is a co-conspirator. But armed robbery is a serious felony.
If I were you, I would focus more on your son's alibi. Does he have one?
And if you are willing to shell out up to $20,000 (which is what it would cost to go to trial) because you believe your son is innocent, I would STRONGLY recommend that you shell out the $200 for a private polygraph first. If your son passes, give the results to his attorney. If he fails, tear up the report, save your money and let him stick with the public defender.