Lost Pet:
 
It is always best to visit the Animal Control Center to visually look for your pet.  File a lost report with Animal Control and local Welfare Organizations such as the Humane Society.  Contact local Veterinarians to see if anyone has contacted them about finding a

pet.  Your postal carrier is a good resource for possibly seeing your pet.  Place a lost pet ad in the newspaper, and posters in the vicinity of where the pets turned up missing.
 
Found Pets:
 
If the pet has rabies tag, you can call Animal Control and they will contact the owner.  If there is no tag, it can be scanned for microchip by Animal Control, the Humane Society, or any Vets office.