Collar, no dog

While out for a brief walk a few hours after the pond incident, an unleashed dog came out of the woods.
As I struggled to keep two leashed dogs under control, one dog resisted quite well, and was able to back up when I wanted him to go forward.  Like a cork exploding from a champagne bottle, the head of said dog popped out of his collar.  I was left holding it in amazement.  It looked like a cowboy's lasso.
The newly freed dog sprinted off to meet his new friends.