Are shock collars allowed to replace a leash?

[Talk Host]

There is a guy who allows his dog to walk through Chatham without a leash. (I'm pretty sure he lives on Raes Hall) It appears he has a shock collar on the dog. (I'm not sure, but there is never a leash) Is a shock collar a permissable alternative to a leash?

[JohnZ]

I think a shock collar is allowable in most states but my spouse doesn't like wearing the darn thing. Go figure.