First make certain your springer wears a collar with a current rabies tag and a current ID tag. Chances are a private citizen will find your dog first and call you. Then, as a backup, microchip your dog in case he does end up in a shelter that checks for chips. The microchip tag should also be on the collar. If your dog becomes lost, circulate flyers with a picture if possible all over the neighborhood.
Many people believe since Springers are hunting dogs that they make good outside dogs.
Springers are people dogs and unless the owner is going to sleep outside with the dog, the dog will not be happy outside. The happiest Springers are dogs that live inside but have a nice big yard for exercise. Most Springers enjoy the company of another dog. Two Springers are better than one. The parent club for the breed, The English Springer Spaniel Field Trial Association, maintains a web site with just about all the information you will need about English Springer Spaniels.