Does your dog wear a collar or a harness?
Our dogs always wore collars, until one day
we were walking Kona at the golf course and she just backed out of her collar. We couldn't believe it. Then it happened with Perry. Finally we wised up and got harnesses
(thats what I call them) We leave them around the house with just a collar because we have double gates, but when we travel we have their collar on with all the tags and also their harness which we connect to the leash. It may sound excessive, but it would only take one time for them to get loose.
Perry may or may not come back if he got loose, but most likely Daisy would be on her way to new adventures, and I could never take that chance.