Many years ago, DOGS helped to get passed a law that requires animal shelters to scan for microchips when an animal arrives at their facilities. One problem has always been determining which registry the owner may have used. Now, thanks to the American Animal Hospital Association (AAHA), there is a central location to look up microchip numbers. Their database includes microchips registered with AKC CAR, HomeAgain, Petlink by Datamars and ResQ by Bayer (AVID, Banfield and 24PetWatch are not included).
The site is www.petmicrochiplookup.org When you enter a microchip number, if it is registered with one of the participating registries, you will be given the number of the proper registry to call to get more information.