I'd call a vet and see if they could get for those microchips. If it is a Lab- there is a strong chance of having a microchip in it, since they are popular pets, popualr breed, etc . I'd might also put an ad in the local newspaper, and put flyers in big stores (target, k-mart, grocery stores etc.) I hope they find their owners or a nice new home. Keep us updated. Good luck.