Ask the shelter staff to show you any sick or injured animals, not just the ones available for adoption. Advertise in the newspaper for several weeks and check the found ads every day. Be certain to inquire regarding any possible matches, not just the likely ones. If you find your pet , please inform the shelters and veterinarians and take down your signs from the neighborhood. It is most likely to either be reunited with its owner, or to find a new home if you bring it to the shelter.
Most papers provide found ads as a free service.