Be sure to have a micro chip installed just under the skin in an ear or between shoulder blades which, if a finder has the sense to have the dog checked by a vet or at a shelter, you will be notified. I had one installed at a special event in a local park and he got a tag for his collar bringing attention to the chip with a tel. number to call. Great service. Costs very little. I think all shelters have the technology to check for the chip.