Originally Posted by hottoddy

I say leave a properly fitted collar (not tight) on, but you're probably OK if your dog is micro chipped.

Even well behaved dogs can get loose when you least expect it. People leave side gates open, doors ajar, latches break, etc. A collar with your phone number gets the dog returned quick if you have good neighbors - before accidents happen. A microchip requires someone to take the dog to a vet or human society for scanning. A dog without a collar is also hard or impossible for strangers to coral safely and apt to wander much further.