OWNER TO DO FIRST
Contact micro-chip company to notify that the dog is lost
Remember, some shelters only keep dogs for 3 days - ACT QUICKLY

OWNER - BRING WITH YOU WHILE SEARCHING  
If there is another dog in the family - BRING IT WITH YOU WHILE SEARCHING
Photos of dog - large ones and in color if possible
Flyers with dog's photo - face view and whole body, description and owners cell phone #
Cell phone ! ! !  Battery charger ! ! 
2 articles of owner's worn and unwashed clothing to leave at the spot where dog was lost & last seen
Bullhorn / Megaphone to call dog
Dog's favorite (familiar) squeaky toy to attract her using Bullhorn
Dog's bed or blanket for SAR dogs or Bloodhounds to smell
Staple Gun and extra staples to put up Lost Posters
Collar, Leash, Muzzle (in case dog is hurt), Blanket, Food and Water in car for dog when found
McDonalds hamburgers to bait dog
Flashlight - yes, even for daytime
Rescue Remedy

BULLHORN / MEGAPHONE - Radio Shack stores sell them  RADIO SHACK

PUT OUT A CB RADIO "LOST DOG ALERT" FOR HELP IN LOCATING DOG

CONSIDER HIRING A PRIVATE DETECTIVE OR BOUNTY HUNTER 

CONTACT THE LOCAL SAR (SEARCH AND RESCUE) GROUP

MAKE FLYERS TO HAND OUT WHILE SEARCHING

MAKE POSTERS - use orange fluorescent paper / poster board only 
TIP:  Use Cell phone # only - do NOT specify $ reward - Say Black & White, not too many
        people know what Harlequin means - Say BIG Great Dane, some don't know a Dane is BIG
        

CONTACT EVERY VET IN THE AREA !  FAX THEM A FLYER

CONTACT EVERY ANIMAL SHELTER IN THE AREA !  FAX THEM A FLYER

CALL RADIO STATIONS TO ASK THEM TO BROADCAST LOST DOG ALERT

WHAT TO DO WHEN YOUR DOG IS LOST: 
Notify all you have previously registered with (Microchip, Tattooing, Identification collars, etc). 
Put out a CB call to all truckers in the area
Contact local SAR ( Search and Rescue ) for help
Use a Bullhorn / Mega-phone to call your dog - Call name, in all 4 directions, then LISTEN for a minute.
Use your dog's favorite squeaky toy over the Bullhorn   
Report to Police and Animal Control and CALL them DAILY - be a pest !
Visit every Humane Society/Animal Shelter within 1 hour drive - in person DAILY - with PHOTO poster
Contact every Vet in the area - leave a poster with them - CALL them all DAILY - be a pest !
Search and re-search the neighborhood DAILY - Call name, in all 4 directions, then LISTEN for a minute.
Flyers/Posters are key - use a photo and description of dog and your CELL phone number
Place "LOST" posters in high traffic areas (Parks, Malls, Bus stops, Grocery Stores etc).
Post flyers at all the dog groomers, dog trainers, pet stores in the area.
Enlist the aid of mail carriers, UPS & FedEx drivers near where dog was last seen
Call all breed clubs and rescue people in the area to help search 
Place an ad in the ALL newspapers 
Scent markers (recently worn UNWASHED owners clothing) left in the area where the dog was last seen. 
Hire a Private Detective / Bounty Hunter
Radio and TV ads 
Renew your ad and don't let it lapse. 
Community bulletin boards 
Call every ad for Great Dane for sale or found dog in the paper 
Search strategy: Someone who found a dog suggested searching a radius of up to 10 miles.
Search: Dress up in a ScoobyDoo costume to search - everyone will notice you, give everyone a flyer
Search: Look near garbage cans, dumpsters, the dog will be hungry.
Search:  at ALL "dog attractive" places such as schools, parks. Post flyers in all of those areas.
Search: Hunting areas - contact Park Rangers and Fish and Game officials. 
Review the deceased animal pick up log at each shelter, DAILY, to rule out the death of your pet. 
Never give a reward to anyone before you have your dog. 
Always meet a person returning your dog at the local Police station.

Do not give up too soon. Keep looking for at least a month. Dogs have been found after several months. 

When you find your dog - go remove all the posters - call radio stations to thank them,
call police, Vets and anyone you asked to help ... so that the next lost dog will get their attention.

Consider a GPS collar for your dog !   
Global Pet Finder  http://www.gpstracks.com  $289 +$12.99 per mo. for monitoring